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Member American Siwiety of Civil Engineers; Member Institution of dvU 

Engineers^ London ; Member Technical Society of the Pacific Coast ; 

Memhiir Engineers and Architects* Association of Southern 

California ; Member Franklin Institute ; Correspond' 

ing Memtfer Amei'ican OeographiccU Society, 




London : CHAPMAN & HALL, Limited. 


Copyright, 1901, 




APR 19 1901 


In 1896 the author was requested to prepare a brief descriptive account 
of such of the principal dams and reservoirs as had come under his observa- 
tion in the course of his professional practice in the arid region of the 
United States, for publication among other Water-supply and Irrigation 
Papers issued by the U. S. Geological Survey for the general information 
of the public on topics of popular interest. 

In compliance with this request a paper was written somewhat hastily 
in the rare leisure intervals of a busy season, which was printed and cir- 
culated as a portion of the 18th Annual Eeport of the Geological Survey, 
in a more pretentious form than had been anticipated when the manu- 
script was prepared. The rapidity with which the edition of the paper was 
exhausted testified to the existence of a widespread interest in the subject 
of water-storage in the West, and a general demand for the facts regarding 
the works which have been built and those which are projected. This has 
encouraged the author to republish the paper in another form, revising and 
adding to it as the material has become available. The work does not 
pretend to be an exhaustive treatise on the subject of dam-construction 
in western America, nor does it assume to cover the field by an account of 
all the important dams which have been built. It is chiefly a straightfor- 
ward description of those works with which the author has become familiar, 
either as a consulting engineer, or as designer and constructor, or merely 
as an interested observer of the development of the ideas of other en- 
gineers. The field is too great to be completely covered by any one work, 
and new projects are developing with such rapidity as to render the task 
of enumerating them all quite beyond the power of any one individual. 

For what it may be worth in the way of information or suggestion to 
the fellow members of his profession, or to others interested in the storage 
of water, the volume is modestly presented, craving indulgence for all 
errors of omission or commission. 

James D. Schuylek. 

OCfTOBER, 1900. 


The development of a water-supply for irrigation in the arid West 
sooner or later reaches a stage where the construction of storage-reseryoirs 
becomes a necessity. If the stream is one of considerable Yolume, numer- 
ous irrigation-canals will be constructed from it at all convenient points, 
and its entire normal flow will be utilized before the impounding of flood- 
volumes is thought of as a possibility. But with the varying seasons there 
will occasionally come a year when the best of streams are so shrunken 
below the normal as to limit sharply the area which can be irrigated from 
it, and emphasize the regret that some means had not been provided for 
holding back the wealth of water which at times pours into the sea without 
benefit to any one, so as to render it available in the drier part of the year. 
Other streams there are, which dram very large districts and at certain 
times of the year are formidable and almost impassable rivers, that in the 
summer and fall are dry for months at a time. If these sources are to be 
rendered servicable storage-reservoirs must be built as the initial step in 
irrigation development. 

All streams, except they be regulated by nature by means of lakes or 
subterranean reservoirs, are subject to great fluctuation. It is the function 
of artificial reservoirs to equalize in a measure these variations in flow, im- 
pounding the floods for use in the season when irrigation is necessary. 
Were it possible to conceive of a stream flowing throughout the year without 
change in volume, such a stream would not have its fullest measure of use- 
fulness without storage of the water flowing during the period of the year 
when irrigation is not needed. 

Inasmuch as the total available water-supply of the arid region is vastly 
short of the quantity needed for irrigating all the land requiring artificial 
watering, it is evident that, under every condition and with every class of 
stream, storage-reservoirs are needed to develop the fullest measure of use- 
fulness of the existing supply. 

Unfortunately it is beyond the possibility of hope that all the water 
flowing can be stored or utilized. There is such a wide range in the total 
run-off of every stream from one season to another that it would rarely be 
possible to flnd storage capaicty for the extremes of flow. On large rivers 


the ratio between maximum and minimum years may vary as 12 to 1, while 
on smaller streams the total flow one year may be one hundred times as 
mu<5h as that of the next year. Hence the reservoirs which might be pro- 
vided to catch all the flow of average years would occasionally be over- 
whelmed by freshets so extraordinary as to fill them several times over. 
This condition has an important bearing on the design of every reservoir 
located in the path of floods, first, in emphasizing the necessity for provid- 
ing ample spillway capacity, large enough to carry safely the greatest possi- 
ble or probable flow, and, second, in fixing the proportion which the 
capacity of the reservoir may bear to the total annual run-off of the stream, 
so as to minimize the ratio of silt deposited to the total volume of water 
impounded. It may be accepted as true that the destiny of every reservoir 
is to be filled with silt sooner or later. If a reservoir were created on a 
stream carrying silt to the extent of 1^ of its volume on an average 
(although few actually carry so much as 1^), and the average annual fiow 
of the stream were, for an extreme example, fifty times as great as the 
capacity of the reservoir, the latter would be filled and become unservice- 
able in two years, assuming that the greater portion of the silt carried was 
deposited in the reservoir. It would evidently, therefore, be unprofitable 
to construct such a reservoir unless provision were made for an immediate 
increase in height of dam, for diverting the river around the reservoir, 
which is usually impracticable, or for sluicing or dredging the silt from the 
reservoir, a process involving great expense. If, on the other baud, the 
reservoir capacity was made great enoagh to store rather more than the 
usual average flow for one year, the period of usefulness of the works would 
be vastly increased, and the consideration of the problem of silt disposal 
would be left for future generations to solve. 

The importance of reservoir-construction and water-storage for irriga- 
tion was not so generally recognized in the arid region prior to about the 
year 1885 as it has been subsequent to that time, and it is only within a 
comparatively recent period that capital has been extensively enlisted in 
such works except for the storage of water for cities and towns. With a 
few prominent examples of successful achievement in that line as precedents, 
however, the subject of water-storage has awakened wide-spread attention, 
and each year it appears to be attracting deeper public interest. Capital 
has been slow to undertake the largest and most important works of this 
character, because of the difficulty of realizing immediate returns upon the 
investment. The development of a new section upon which water is but 
recently introduced, the constraction of distributing canals, ditches, and 
pipes, the cultivation of the land and the planting of orchards — in fact the 
conversion of a desert to a condition of profitable productiveness, is the work 
of time, which cannot be begun until the irrigation-works are actually com- 
pleted, and when begun is slow of full development. Meantime, however^ 


the interest accoant accnmnlates, and often is so far in excess of possible 
revenues as to bring discouragement, and sometimes actual bankraptcy, 
before a paying basis is reached. The uncertainty of the laws of the differ- 
ent iStates governing water rights in reservoirs, the difficulty of establishing 
fixed rates for water that will be high enough to afford an adequate revenue 
to the capital involved and low enough to enable the farmer to pay for the 
water he requires and make a living while developing his farm, and the 
responsibilities involved in the risk fiom floods, accidents, and dry seasons, 
have been potent in deterring capitalists from investing in the business of 
storing and selling water, per se^ unless it were coupled with the ownership 
of the lands to be irrigated, or with the domestic supply of a growing town, 
or with the possibilities of generating water-power. 

The recent development of electrical machinery, by which power may 
profitably be transmitted long distances with comparatively small loss, has 
indirectly benefited the irrigation development of the country by adding 
an incentive to the construction of storage-reservoirs for the primary and 
more profitable purpose of generating power. Many reservoirs are being 
favorably considered by capitalists for the power which they will afford that 
would otherwise be regarded as comparatively valueless or unprofitable 
investments for irrigation alone. As the great bulk of precipitation in the 
arid region occurs in the mountains, where it increases with some degree of 
uniformity with every foot of increased altitude, the mountains are coming 
to be regarded as indispensable to the wealth of the country, valuable not 
only for their precious metals, stone, and timber, but for the store of water 
which they are able to supply to the thirsty plains below. The mountains 
not only supply the water, but they usually afford the best sites for reservoirs 
to impound it, in ancient lake-beds, and high, cool, deep valleys, surrounded 
by forests; while the latter fulfil a most important function and attain a 
value far higher than the mere commercial one to be derived from their 
lumber and firewood, by serving to retard the rapid run-off of the water- 
supply. Forest growth is of primary importance in the preservation of the 
source of streams, in preventing the mountains from being washed down 
wiCh destructive force to the valleys and the sea, and in creating natural 
reservoirs on every square mile of their surface. 

That storage-reservoirs are a necessary and indispensable adjunct to 
irrigation development, as well as to the utilization of power, requires no 
argument to prove. That they will continue to become more and more 
necessary to our Western civilization is equally sure and certain; but the 
signs of the times seem to point to the inevitable necessity of governmental 
control in tlieir construction, ownership, and administration. Those which 
private capital may undertake should only be permitted to be erected under 
the most rigid governmental supervision, to assure their absolute safety. 
Many reservoirs are needed for the development of the arid regions which 


are of too great a magnitade to be andertaken by privato capital or organized 
indiTidaal efiFort. In e^ery other coantry sach works are andertaken by 
the national government. In general it may be said that the lands which 
would be benefited by such works in arid America belong to the govern- 
ment. To make these lands productive and capable of sustaining popula- 
tion, the government of the United States should undertake their reclamation 
and construct and administer the reservoirs. That such a policy will ere 
long be inaugurated seems inevitable. The purpose of this work is to 
familiarize the public with the details of constraction and the general 
features of interest appertaining to the principal reservoirs constructed or 
projected in the Western States and Territories which have come within the 
knowledge or observation of the writer, describing in a popular way their 
characteristics, their water-supply, the results accomplished or sought to 
be accomplished by them, and the methods and materials employed in the 
construction of the dams which form them. 




Varioas types of rock-fill dams described. — The Esoondido dam, faced with 
redwood plank— the first rock-flU dam built for irrigation storage. — Lower Otay 
steel-core, rock-fill dam, general description of construction. — Morena rock-fill 
dam, with concrete facing. — Barrett dam, ander construction. — Upper Otay dam, 
projected and begun. — Ghatsworth Park rock-fill, with concrete and masonry 
tikin, — The Pecos Valley, N. M., type of rock-fill dams, with earth facing. — Quick- 
opening spillway gates. — ^Walnut Grove rock-fill dam, and its disasterous failure.^--'^' 

East Canyon Creek rock-fill dam, with plate-steel center-core. — South Platte 

dam. — ^The English dam, Cal., timber-crib rock-fill. — The Bowman dam, an exist- 
ing example of earlier rock-fill construction. 


Htdbaulic-fill Dahb 70 

Principles of dam construction by the agency of water. — San Leandro and 
Temescal dams, supplying Oakland, Cal., partially built by the hydraulic method. 
— The Tyler, Texas, hydraulic-fill dam, the cheapest on record.— La Mesa, Cal., 
hydraulic-fill dam, and the assorting of rock and earth by the varying velocities 
of water. — The Lake Christine hydraulic-fill dam, San Joaquin River, Cal., in 
process of construction. — The filling of high trestles with earth and rock embaok- 
ment by hydraulic methods on the Canadian Pacific and Northern Pacific railways, 
as illustrating the principles of hydraulic dam construction.— Hydraulic construe* 
tion at Seattle, Tacoma, and elsewhere. 


Mabonbt Daks 117 

Elementary principles involved. — Curved ««. straight masonry dams. — The 
advantages of curvature in all masonry dams as a safeguard against cracks due to 
extreme changes of temperature. — The old Mission dam, erected by the Jesuit 
Fathers near San Diego, Cal., one of the first structures of its kind in America. — 
£1 Molino dam. — The Sweetwater dam, its original design, construction, severe 
test and subsequent enlargement. — The silt problem in the Sweetwater reservoir, 
i— The Hemet dam and the irrigation of land from Lake Hemet reservoir. — The 
Bear Valley dam, the slenderest dam of its height in the world. — La Grange 
dam, the highest oTerflow dam In America.— The Folsom dam, Cal., erected by 




convict labor.— The San Mateo, Cal., concrete dam, the greatest mass of concrete 
in existence. — Ran-off of streams supplying the San Mateo and adjacent reser- 
voirs. — Pacolma submerged dam. — Agua Fria dam, Ariz., and the limited volume 
of underflow in streams shown by its construction. — The Seligman dam. — The 
Williams dam. — The Walnut Canyon dam, Ariz., and the phenomenal leakage of 
the reservoir behind it. — The Ash Fork, Ariz., steel dam, the only one of its type 
in the world. — The Lynx Creek dam, and its failure, a conspicuous example of y 
how dams should not be built. — Concrete dams at Portland, Oregon. — The Basin 
Creek, Mont., masonry dam. — A masonry dam under 640-ft. head. — New Croton 
dam. New York, and other dams of the New York City water-supply works. — 
Indian River dam. — Cornell University dam and the provision made for con- 
traction cracks— Bridgeport and Wigwam dams. Conn. — The Austin dam and its ^ 
recent failure. — Masonry dams in Guanajuato, Mexico. — Foreign dams of Spain, 
France, Belgium, Italy, Wales, Algiers, Germany, Egypt, India, China, and 


Eabthbn Dahb 274 

Ancient earth dams of Ceylon and India, of enormous dimensions. — Modern 
dams of India. — General principles to be observed in earth dam construction. — 
The Vallejo dam. — Cuyamaca dam and reservoir and the irrigation system sup- 
plied. — Merced reservoir dam. — Buena Vista Lake dam. — Pilarcitos and San 
Andr6s dams, supplying San Francisco. — Cache la Poudre dam. — Earth dams 
erected by the State of Colorado. — Doubtful results of State construction of stor- 


Natural RESERYOnis 209 

The Alpine Reservoir, Cal., formed by an earthquake. — Twin Lakes Reservoir, 
Colo. — Larimer and Weld natural reservoir. — Marston Lake, supplying Denver. — 
Loveland basin. — The Laramie basin, Wyo. — Lake de Smet, Wyo. — Natural 
gravel-bed storage-reservoirs on the Los Angeles, San Gabriel and Santa Ana 
rivers, in Southern California. 

Projected Reseryotrs 814 

Reservoir surveys made by the U. S. Geological Survey, tables of capacity and 
area, and contour maps in Appendix. — Government surveys in Wyoming and Col- 
orado, reported on by Col. H. M. Chittenden, Corps of Engrs., U. S. A. — Govern- 
ment reservoir surveys on the Gila River, Arizona, to provide storage water for 
irrigation on the Gila River Indian Reservation. — The San Carlos, Riverside, and 
Buttes sites. — The Tonto Basin reservoir, Ariz., and the projected mammoth dam 
of masonry. — Proposed reservoirs on Rio Verde, Arizona. — Projected dam in Bear 
Canyon, near Tucson, Arizona, for power and irrigation. — Proposed dams and 
reservoirs on the Rio Grande in New Mexico and Texas. — The Elephant Butte 
masonry dam. — Run-off of the Rio Grande and water-supply available for irrigation. 
— Proposed reservoirs in Texas. — Caimanche Lake. — Nueces reservoir, — Fria River 
reservoirs. — Sand Lake reservoir. — Upper Pecos reservoir-sites in New Mexico. — 



Projected dam and reservoir on Rock Creek, Nev., for irrigation in tbe Hnmboldt 
Vallej. — Lost Canyon, Colo., natural rock-fill dam. — Projected reservoirs in Cali- 
fornia. — The Little Bear Valley dam, of concrete, in process of construction by tbe 
Arrowhead Reservoir Co. — Huston Flat reservoir-site, and its projected hydraulic- 
fill dam. — Grass Valley reservoir-site. — The projected masonry dam at Victor, Cal. 
on the Mojave River. — Projected reservoirs in San Diego Co. — Proposed reservoirs 
on Kern River, Cal. — ^The Manache Meadows site and the project of the Kern- 
Rand Reservoir and Electric Co. for power utilization. — Kern Lake reservoir-site. — 
Big Meadows. — Utilization of natural lakes. — The enterprise of the Great Plains 
Water Co. in the Arkansas Valley, Colo., in the storage of flood waters in enor- 
mous natural basins. 


Containing tables of reservoir areas and capacities of selections made by U. S. 
Geological Survey — tables of capacities of various reservoirs in service — tables 
of cost of reservoirs per acre-foot of reservoir capacity, etc 385 



1. Map of Escondido Irrigation District and System of Works 2 

2. Feeder Canal on the Side of Rodriguez Mountain, Escondido Irrigation District 8 
8. Feeder Conduit of Escondido Irrigation District 6 

4. Escondido Irrigation Dam, looking north, showing Spillway 7 

5. Back of Escondido Irrigation Disirict Dam 9 

6. Plans and Profiles of Escondido Dam 13 

7. Details of Gate of Escondido Dam 18 

8. Pick-up Weir at Head of Distributing Sjstem in Escondido Irrigation District. 14 

9. Contour Map of Reservoir of Escondido Irrigation District 16 

10. Construction of Facing of Escondido Dam 17 

10a. Escondido (Cal. ) Rock-fill Dam— Wooden Lining .facing page 18 

106. Site of Dam, South Platte Reservoir Site — Narrowest Part facing page 19 

11. Masonry Foundation of Lower Otaj Dam 21 

JJ^- i Otay (Cal.) Rock-fill Dam— Steel Core facing pages 22. U 

12. Steel Web-plate and Anchor- trench at West End of Lower Otay Dam 28 

12a. Otay (Cal.) Rock-fill Dam— Steel Core. facingpage 25 

18. Crest of Lower Otay Dam, showing Web-plate of Steel embedded in Concrete. 

Dam nearing Completion 25 

aS. Map of Lower Otay Reservoir 26 

*^15. Plans of Lower Otay Reservoir 28 

16. Explosion of Great Blast at Lower Otay Rock-fill Dam 29 

17. Barrett Dam. .' 88 

18. Morena Dam-site, looking Eavt 87 

19. Morena liock-fiU Dam in Process of Construction. Showing Top of Toe-wall 

above the Water-line 89 

20 Murena Rock-fill Dam, showing a Portion of Toe- wall under Construction 40 

v^21. Reservoirs near San Diego, California 41 

22. Upper Otay Dam, Foundation Masonry 42 

28. Sketch of Reconstruction of Chatsworth Park Rock-fill Dam 44 

24. Castlewood Dam, Colorado : Plan, Sections, and Elevation 46 

24a. View of Castlewood Dam, Colorado, during Construction, looking North 

farcing page 46 

246 View of Castlewood Dam and Reservoir, Colorado .facing page 47 

25. Sketch-map of Dam at Head of Pecos Canal 47 

26. Lake Avalon Dam. Rock-fill in Process of Construction 48 

27. Lake Avalon Dam, Pecos River, New Mexico. Showing the Crest of Com- 

pleted Dam and Spillway Discharging 49 

28. Canal Headgates, Lake Avalon Dam 50 

29. Quick-opening Qates in Spillway of Lake Avalon Reservoir, Pecos Valley, New 

Mexico 61 




80. Sections of Lake Avalon and Lake McMillan Rock-fill and Earth Dams, Peooa 

Valley, New Mexico 51 

81. Sketch-map of Pecos Valley Canals 52 

^83. Map of Pecos Valley, New Mexico, showing Location of Reservoirs and Canals 55 

88. Cross-section and Elevation of Walnut Grove Dam, Arizona 59 

84. View of Walnut Grove Dam, Arizona 60 

85. East Canyon Creek Dam, Utah. Rock-fill with Steel Core 65 

86. Balanced Valve, used for Reservoir Outlet, South Platte Rock-fill Dam 68 

87. South Platte Rock-fill Dam. View of False Work and Bridge over tbe Dam-site 60 
87a. Site of Dam, South Plate Reservoir Site — Above .facing page 71 

88. Map of Reservoir formed by Rock-fill Dam on South Platte River, Colorado ... 72 

88a. Plan and Cross-section of the Bowman Dam facing page 74 

886. Plan and Cross-section of the Fordyce Rock-fill Dam, California. . ,facing page 75 

80. Plans and Cross-sections of San Leandro and Temescal Dams 78 

40. Hydraulic-fill Dam at Tyler, Texas, showing Delivery-pipe supported on a 

Grade-line, carrying Material to Opposite Side, and Spillway Cut made by 

sluicing the Earth into Base of Dam 70 

41. Hydraalic Sluicing for building Dam at Tyler, Texas 81 

42. Hydraulic-fill Dam, at Tyler, Texas, in Process of Construction • . . 85 

48. View of Finished Dam and Wasteway of La Mesa Reservoir 87 

43a. La Mesa (Cal.) Dam in Course of Construction by the Hydraulic Process 

facing page 84 

44. La Mesa Reservoir. Beginning of the Construction of Hydraulic-fill Dam 91 

45. Details of Outlet-gate and Well-culvert of La Mesa Dam 08 

46. Construction of Hydraulic Dam, La Mesa Reservoir, illustrating the Method of 

Suspending Pipes 05 

47. Cross-section of La Mesa Dam 07 

48. La Mesa Hydraulic-fill Dam, showing Pipe Discharging Material on the Dam. . 08 
48a. View of Lake Christine Dam-site, showing Outlines of Hydraulic- fill Dam 

facing page 03 
48&. View of Lake Christine Dam-site, San Joaquin River, near Fresno, California, 

where a Hydraulic-fill Dam is in Process of Construction .facing page 00 

40. Hydraulic Sluicing, Canadian Pacific Railway. View of Pit, and Hydraulic 

Giant at Work 101 

50. Hydraulic Fills, jMurtially completed, at Mountain Creek, B. C, Canadian Pa- 

cific Railway 107 

51. Hydraulic Filling of High Trestle at Mountain Creek, B. C, on Canadian Pa- 

cific Railway, near View of Dump 100 

52. Northern Pacific Railway. Bridge 100 Ill 

58. Northern Pacific Railway. Bridge 180, Cascade Mountains 112 

54. Northern Pacific Railway, Hydraulic-fill Construction. View in Pit showing 

Hydraulic Giant in Action 118 

55. Northern Pacific Railway, Bridge 184. Hydraulic Filling in Progress 114 

56. Comparison of Profiles of Zola, Sweetwater, and Bear Valley Dams 120 

57. Old Mission Dam, near San Diego, Cal. The First Irrigation Dam built in the 

United States 128 

58. Original Sweetwater Dam as completed to the Sixty-foot Contour 127 

50. Elevations and Sections of Sweetwater Dam 120 

60. Face of Sweetwater Dam in 1800. After Two Years of Drouth 180 

61. Details of Tower of Sweetwater Dam 183 

62. Sweetwater Dam as finished, April, 1888 188 



68. Sweetwater Dam daring tlie Great Flood of January 17, 1895 185 

68a. Sweetwater (Cal.) Masonry Dam .facing page 187 

64. Spillway of Sweetwater Dam, seen from Below 189 

65. Sweetwater Dam, showing New Apron of Spillway and Protecting Spar- walls 

on Pipe-line 141 

66. Repairing and Increasing tbe Height of the Parapet of Sweetwater Dam 148 

67. Plan of Sweetwater Dam 145 

68. Profile and Sectional View and Plan of Wasteway Tannel, Sweetwater Dam... 145 

69. Details of Sweetwater Dam 145 

70. Sweetwater Dam, showing Head of Outlet Tunnel and Spillway 147 

71. Map showing Ix)cationof Lake Hemet, the Main Conduit, and Irrigated Lands. 158 

72. Hemet Dam, Riverside County, California 155 

78. Hemet Dam as finished, showing the Spillway Ridge south of the Dam 157 

74. Contour Map of the Lake Hemet Reservoir 159 

75. Hemet Dam, Riverside County, California 160 

76. Hemet Dam Construction Plant 161 

76a. Lake Hemet (Cal.) Masonry Dam .facing page 16S 

77. Cross-section of Bear Valley Dam 165 

78. Plan and Elevation of Bear Valley Dam 165 

79. Bear Valley Dam, looking south, toward Spillway 167 

80. Spillway of Bear Valley Dam, with Flashboard Gates 169 

81. Base of New Rock-fill Dam, Below the Bear Valley Dam 171 

82. Map of Bear Valley Reservoir 175 

82a. Plan of La Grange Dam, California • 177 

826. Profile of La Grange Dam, California 177 

88. Upper Face of La Grange Dam 178 

84. Ijower Face of La Grange Dam 179 

85. La Grange Dam, California, during Constuctiun — finishing the Crest 181 

|!^- 1 La Grange Dam. California 181 , 188 

88. La Grange Dam. California, daring Flood 188 

89. Map showing Location of Folsom Dam and the Main Canal 185 

90. Plan, Cross-section, and Elevation of Weir and Headw^orksof Folsom Canal. . . 186 

91. American River Dam at Folsom 187 

92. Hydraulic Jacks for raising Shutter on Folsom Dam 189 

93. View of Masonry Dam on American River, California, at the Folsom State 

Prison, sliowing Canal Head-gates 191 

94. Plant for Mixing and Handling Concrete at San Mateo Dam 198 

95. Construction of Intake of San Mateo Dam 195 

96. Moulds for Concrete Blocks, San Mateo Dam 197 

97. Roughening Surface of Concrete Blocks to receive Fresh Cement, at San Mateo 

Dam 199 

98. San Mateo Dam being Inspected by American Society of Civil Engineers in 

July, 1896 201 

99. Plans and Sections of San Mateo Dam and Map of Crystal Springs Reservoir 

facing page 208 

100. The Newell Curve 204 

101. Excavation of Trench for Pacoima Subterranean Dam 207 

102. View of Flood passing over Pacoima Subterranean Dam 209 

108. Plan and Profile of Pacoima Dam. ... 211 

104. Measuring-box 21^ 



lOo. Cross-sections of Agua Fria Diverting-dam and Storage-reservoir Dam, Arizona. 213 

106. Foundations of West Ciiannel of Agua Fria Diverting-dam 215 

107. Diverting-dam of the Agua Fria 217 

108. Submerged Storage- and Diverting-dam, near Kingman, Arizona 219 

109. Seligmau Dam, Arizona 220 

110. View of Upper Face of Seligman Dam daring Construction 221 

111. Section and Profile of Seligman Dam 222 

112. Ash Fork, Arizona, Steel Dam, View of Steel Construction from Lower Side. . . 225 

113. Ash Fork, Steel Dam, showing Frame ready to receive Plates 225 

114. Ash Fork Reservoir 226 

115. Walnut Canyon Dam, Arizona 227 

116. Section and Profile of Walnut Canyon Dam, Arizona 227 

117. Lynx Creek Dam, Arizona, after Kupture by Flood. View from below 228 

118. Lynx Creek Dam, Arizona. Section showing Facing Walls, and Concrete Heart- 

ing 229 

119. Inner Face of Concrete Dam at Portland, Oregon 231 

120. Exterior View of Reservoir Dams at Portland, Oregon 233 

121. Reservoir No. 2, Portland, Oregon, showing Aerating Fountain 125 feet high. . 235 

122. Masonry Dam under 640-foot Head, the Greatest Recorded Water-pressure on 

Masonry 236 

123. Austin Dam and Power-house, Texas 243 

123a. Austin Dam, during Flood of April 7, 1900, and immediately before the Break 245 
1236. Austin Dam, Texas. View taken during Flood, a few Minutes after the 

Break 247 

123(;. View after Subsidence of Flood of April 7, 1900, showing Section of Masonry 

moved bodily Downstream 247 

124. Upper Dam at Guanajuato, Mexico 249 

125. Lower Dam, or •• Presla de la OUa '* Guanajuato, Mexico frontispiece 

126. The Ekruk Tank, Bombay, Plan and Details 276 

127. Cross-section of the Ashti Dam, India 278 

128. View of Cuyamaca Dam and Outlet Tower 283 

129. Masonry Diverting-dam of the San Diego Flume Co., California 288 

130. Plan and Elevation of Diverting-dam of San Diego Flume Co., California 286 

181. Sample of High Trestle Construction on San Diego Flume, California 287 

131a. Map showing Location of Merced Reservoir, California 290 

132. View of Yosemite Reservoir, Merced, California 291 

^ 133. Reservoir of South Antelope Valley Irrigation Company 801 

134. Map of Little Rock Creek Irrigation District 302 

135. View of a Corner of the Basin of Alpine Reservoir before Work was Begun.. .. 805 

[ 36. Details of Tunnel-outlet of the Alpine Reservoir 804 

[37) Arkansas River Basin. Twin Lakes Reservoir-site .facing page 307 

Detail's of Outlets for Twin Lakes, Colo 308 

189. The ** Devil's Gate," Sweetwater River. Wj^oming 817 

140. Contour Map of Buttes Reservoir-site, Gila River. Arizona .facing page 853 

141. Longfitudinal Section of Buttes Dam-site, Gila River. Arizona 823 

142. Section of Proposed Rock-fil' Dam at the Buttes, Gila River. Arizona 824 

143. Section of Proposed Buttes Dam through Spillway, showing End Wall of Rock 

Fill 824 

y 144. PlanofButtesDam-site, showinq: Location selected for Rock-fill Dam /(7«w/7;?«.<7e 825 
{ 145. Plan of Riverside Dam-site, Gila River, Arizona, showing Location selected for 

Proposed Masonry Dam 325 



146. Contour Map of San Carlos Reservoir-site, Gila River, Arizona. . . . facing page 827 

147. Longitudinal Profile of Sau Carlos Dam-site, showing Elevation of Proposed 

Masonry Dam 836 

148. Contour Plan of San Carlos Dam-site, showing Location selected for Proposed 

Masonry Dam .facing page 329 

149. Maximum Profile of Proposed San Carlos Dam of Masonry 827 

149n». San Carlos Dam-site, looking Down-stream .facing page 829 

150. Section of San Carlos Dam through one of the Outlet Towers, illustrating 

Arrangement of Control 828 

151. Details of Outlet Tower and Gates. San Carlos Dam, Gila River, Arizona.. . . . 829 

152. San Carlos Dam, Arizona, Section through Spillway 829 

152a. San Carlos Dam-site, looking Down-stream 831 

153. Boring Apparatus 881 

154. View of San Carlos Dam-site, Gila River, Arizona 338 

154a. View of Left Abutment V^all, San Carlos Dam-site, showing Dip of Lime- 
stone 885 

155. View of the Buttes Dam-site, looking Down-stream 835 

155a. Buttes Dam-site, looking Up-stream from Upper Toe 337 

156. Buttes Dam- site, looking Up-stream; Proposed Quarries on Left ; Spillway on 

Left Center of Field 887 

157. View of Riverside Dam-site, Gila River, Arizona 889 

158. Plan of Tonto Dam 340 

159. Sections of Dam and Canyon of Tonto Reservoir 841 

160. Map of Tonto Basin Reservoir, showing Elevations of Ten Cross-sections of the 

Reservoirs 842 

161. Tonto Basin Dam-site, Salt River, Arizona, looking Down-stream 848 

162. Dam-eite on Salt River below Mouth of Tonto Creek. 845 

168. Map of Gila and Salt River Valleys, showing Existing and Proposed Irrigation 

Works .facing page 846 

164. Map of Salt River Valley, showing Canals Constructed and Proposed facing page 847 

165. Map of Site of Horseshoe Reservoir, on Verde River 347 

166. Map of Lower Portion of McDowell Reservoir 349 

167. Elephant Butte Dam on Rio Grande, above El Paso, Texas. Plan and Section 

of Dam-site, Profile of Dam, and Plan of Outlets 855 

168. Map of Elephant Butte Reservoir on the Rio Grande 356 

169. Diverting-dam near Fort Selden, Texas, in Process of Construction 357 

170. Wood-stave Pipes, laid under Bed of the Rio Grande 860 

171. Map of Rock Creek Reservoir, Canal Lands, and Lands to be Irrigated 364 

172. Plan of Dam-site and Reservoir-site, Rock Creek, Nevada 365 

173. Sketch of Longitudinal Section of Lost Canyon Natural Dam 866 

174. Sketch of Cross-section at Upper End of Lost Canyon Natural Dam 367 

174a. Comparison of Dams of the System of the Arrowhead Reservoir Company. . . . 369 
174d. View of Huston Flat Reservoir-site 371 

175. Map of Little Bear Valley Reservoir facing page 372 

176. Map of Sources of Water-supply in the Vicinity of San Diego, California 

facing page 378 

177. Cross-section of Dam-sites in San Diego County, California 878 

178. Map of Watershed and the Lands to be Irrigated from Victor Keservoir 874 

179. Cross-section of Dam-site 375 

1 80. View of Victor Dam-site looking Up-stream 377 

181. Map of Victor Reservoir 879 




lb2. Map of Manacbe Meadows Reservoir 880 

188. Map of Manache Meadows Dam-site. 861 



1. Eleanor Lake Reserroir-site. 

2. Toulume Meadows Reservoir-site. 
8. Little Yosemite Reservoir-site. 

4. Kennedy's Lake and Meadows Reser- 



5. Donner Lake Reservoir-site. 

6. Hope Valley Heservoir-site. 

7. Independence Lake Reservoir-site. 

8. Webber Lake Reservoir-site. 

9. Long Valley Reservoir-site. 


10. Cottonwood Lake Reservoir-site. 

11. Sugar Loaf Reservoir-site. 

12. Monument Reservoir-site. 

18. Tennessee Park Reservoir-site. 

14. Clear Creek Reservoir-site. 

15. Hay den Reservoir-site. 
Leadville Reservoir-site. 


16. Sun River Reservoir System, Reser- 

voir No. 1. 

17. Reservoir No. 2. 

18. Reservoir No. 8. 

19. Reservoir No. 4. 

20. Reservoir No. 5. 

21. Reservoir No. 6. 

22. Reservoir No. 7. 
28. Reservoir No. 8. 

24. Reservoir No. 9. 

25. Benton Lake Reservoir. 




The natural fertility of reeoarce in the American people has led to 
many novel experiments in the conBtrnction of dams to adapt them to the 
materials most conveniently available, and this has resulted in the develop- 
ment of nnmerons interesting types. Among these the most conspionoas 
are the rock-fill dams, which may be said to have originated forty to fifty 
years ago in the mining region of California, where dams were bnilt in re- 
mote and almost inaccessible locations, to which the transportation of cement 
was impracticable. These were considered to be of a temporary nature, where 
dams of permanent masonry were not warranted, but where a water-supply 
for mining purposes needed to be impounded. They began with timber or 
log cribs filled with loose stone. Their next stage was an embankment of 
loose stone a portion of which was laid up as a dry wall, with a facing of 
two or more thicknesses of plank to secure water-tightness. The latter 
type has proven so serviceable that it is still regarded as one of the most 
desirable classes of dam that can be built, where economy is of prime consid- 
eration. In the attempt to secure a greater degree of durability other types 
have been developed as follows : 

1. Rock-fill dams with facing of asphalt concrete laid on a sloping dry 

2. Rock-fill dams with a central core of steel plates, and without hand- 
laid facing- walls. 

3. Rock-fill dams with facing of Portland-cement concrete laid on dry 

4. Rock-fill dams with facing of masonry, built vertically, backed with 
earthy and covered on the lower side with blocks of stone laid in mortar. 


5. Kock-fiU (lamB with facing of steel plates laid on the sloping interior 
sarface on a dry hand-laid wall. 

6. Rock-fill dams with facing of earth. 

Existing examples of these Tarions types and the irrigation systems sap- 
plied by them will be considered in the following pages. 

The Escondido District Dam, California. — Few of the irrigation districts 
organized in California under the well-known Wright law have been sac- 


Pig. 1. — Map of Escondido Irrigation District akd System of Works. 

cessfal in accomplishing the pnrpose of their organization, and many 
disastrous and lamentable failures have to be recorded in the practical 
operation of a law which, at one time, was looked upon as a wise and 
feasible measure for the general irrigation of the arid lands of the States. 
Among the very few that succeeded in selling bonds and constructing a 
storage-reservoir and distributory system is the Escondido district in the 
northern portion of San Diego County. The district (Fig. 1) is in a valley 
whose description is implied by its Spanish name, Escondido — ^hidden. It 
is surrounded by mountains and embraces 13,000 acres. The storage-dam 
supplying the district is located on the Yon Segern branch of San Elijo 


Greek, which passes through the town of Escondido. It is aboat two miles 
east of the district at its nearest point, and at an elevation of 1300 feet 
above sea-level, or about 650 feet above the town. 

The immediate watershed tributary to the reservoir measures about 
8 square miles, which in that region affords insufficient run-off to fill the 
reservoir, although adding materially to it at times of heavy rainfall. 
Hence the main supply had to be brought to it from the San Luis Bey 
Biver, the nearest stream to the north, by a conduit which taps the river at 
an altitude of 1600 feet, in a wild, rocky canyon, which is almost inaccessi- 
ble by reason of its roughness. The conduit has a capacity of 28 second- 
feet, and is 5.6 miles long, consisting of 67,287 feet of ditch built along the 
rugged mountain-side (see Fig. 2), 14,142 feet of flume, and 806 feet of 
tunnel. The intake is made by a tunnel 356 feet long, heading in the river 
3 feet below low-water level, while at the other end the rim of the reservoir- 
basin is pierced by a second tunnel 450 feet long. This tunnel discharges 
into a ravine leading down to the dam, 3^ miles below. The intake tunnel 
is cut through solid granite, which is excavated below grade at its lower 
end to form a settling-basin, in which sand accumulates at the rate of about 
1000 cubic feet daily. This is sluiced back into the river by the opening of 
a side outlet-gate. By this means the water of the conduit is kept com- 
paratively clear and but little sediment has accumulated in the reservoir. 

The upper 8000 feet of the condait consists of a flume (Fig. 3), sup- 
ported on posts on the sides of a rugged canyon, which in places presents a 
vertical face of considerable height. The lumber of this flume was hauled 
by a roundabout road to a blaff on the opposite side and 600 feet above the 
river-bed, whence it was transported by a wire cable with a span of 1500 
feet by means of a trolley manipulated by hand windlass and rope. At 
other points the lumber was hoisted to the line by horse-power, by means 
of a car and portable track several hundred feet in height. The flumes 
are mainly 4 feet wide by 3 feet deep, and the ditch is excavated with a 
bottom width of 5 feet and side slopes of 1 on 1, the minimum excavation 
on the lower side being about 3 feet. The formation throughout that 
region is granitic, partially decomposed, the disintegration of the rock 
forming a few feet of soil, from which protrude large bowlders of very hard 
granite embedded in softer rock in situ. 

The total cost of the conduit was $116,328.60, or $1.29 per foot for 
construction and engineering, and 12 cents per foot for right of way, com- 
missions, etc. The conduit is capable of filling the reservoir to its present 
capacity in a little over sixty days when running to its full capacity. 
Should the dam be completed to the height of 110 feet as it has been pro- 
jected, the conduit would require to run full for rather more than six 
months to fill the enlarged reservoir. 

In seasons when the precipitation exceeds 20 inches the run-off from the 


immediat« watershed above the dam ie alone expected to fill the reservoir 
as at prBHent constracted. For the preaerration of the main coadait, of 
which Dearly 30^ \i wooden flume which ahoald be kept wet for proper 
maiutenance, it would be desirable to maintain a flow of water throagh it 
the entire season. For this pnrpose the constrQction of an anxiliary reeer- 

Fio. 8.— Fkedbr CoNDDtT OF Ebcondido Irbioation DiarrticT. 

Toir at the head of the conduit is regarded aa one of the most desirable of 
the projected improvements to the system. A very capacions reeervoir-site 
exists at Warner's Bancb, 15 miles aboye the head of the canal, where the 
drainage of 210 square miles of watershed may he imponnded. A much 
greater volume of water can here be stored than wonld he needed by the 
district. In fact the capacity of a reservoir with a dam 100 feet high at 
this point would be 193,200 acre-feet, covering 5535 acres, which is far 
beyond the probable yield of the watershed in years of masimnm rainfall. 


A. orosB-eectioti of the dam-sito is shown in Fig. , where the width of the 
site at 100 feet ie soen to be but 690 feet. A more modest dam of earth, 
36 feet high, to hold 30 feet depth of water aad to impound 6400 acre-feet 
in a reservoir covering 740 acree, wonld serve all the requirements of the 

Fro. 4.— Ebcondldo Ibiuoation Dam, lookiko horth, showino Spillway. 

district and at moderate cost, provided the land is obtained at reasonable 

The Eecondido dam is of the ordinary type of rock-fill, with facing of 
redwood plank. In this respect it resemblea the mining dams of northern 
California, althoagh the nae of redwood has given the facing a longer life 
than the more perishable pine used in the North. This structare appears 
to have been built with nuasnal care, and though ragged and onfinished in 
appearance, it is of ample dimensions for the pressures it withstands and ie 


reasonably water-tight. It is 76 feet high, 380 feet long on top, 100 feet 
on bottom, with a base of 140 feet, and a thickness at the crest of 10 feet. 
A spillway has been excavated at the north end on the right bank of the 
reservoir, in solid rock, 25 feet wide, its bottom being at the 71-foot 
contonr, or 5 feet below the crest of the dam. This is left open and 
nnobstracted, although it has been customary near the end of the rainy 
season to build a barrier of sand-bags across it in order to impound a greater 
depth of water, after the danger of floods is presumed to be over. 

The slopes of the dam are ^ to 1 on the water-face, and on the back 
1 to 1 for half the height, flattening to 1^ to 1 from mid-height to base. 
The cubical contents are 37,159 cubic yards, of which 6000 yards were 
hand-laid in courses of dry rubble on the face, the thickness of the wall 
being 15 feet at bottom, and 5 feet at top. The remainder consists of 
loose, angular blocks of granite, of all sizes up to 4 tons weight (Fig. 5), 
which were loosely dumped from cars and placed to some extent with 
derricks. No small quarry-spa wis or earth were used, and the result is a 
clean rock-fill, which has not settled more than three inches since its final 
completion. No large ledges affording well-defined quarries of any con- 
siderable extent were uncovered in the course of construction, but all the 
material was taken from scattered bowlders and rock-masses protruding on 
either side of the canyon above and below the dam for a distance of 800 
feet. Temporary tramways were built at different levels on either side, as 
the dam rose in height, so arranged as to permit the cars to run to the dam 
by gravity, the empty cars being hauled back by horses. These tracks were 
carried across the dam on elevated trestles, the posts of which remain buried 
in the embankment. This arrangement involved the pushing of the cars 
across the trestle by hand, which was a slow and expensive process. The 
entire method of work was costly and inconvenient compared with the 
modern systems of cable way transportation of such materials. 

In stripping the foundations bed-rock was found about 4 feet below the 
bed of the creek, nearly level across the canyon from side to side. The top 
soil was removed over the entire base of the dam and the filling of rock 
placed directly upon the granite foundation. The bed-rock was of the 
formation described as prevailing along the main conduit, which is a 
common characteristic of southern California, and consists of disintegrated 
granite holding hard bowlders indiscriminately through it. The formation 
is not impervious to water, and for that reason is not considered a desirable 
or satisfactory foundation for a heavy masonry dam because of the resultant 
upward pressure on the base due to that condition, but for a rock-fill struc- 
ture of this class it is unobjectionable. Into this bed-rock a trench was 
excavated at the upper toe of the dam, from 3 to 12 feet deep, which was 
refilled with rubble masonry 5 feet thick, laid in Portland -cement mortar. 
Into this masonry was embedded the plank facing, which was thua 

• / » 


coanected all aroand the toe with the canyon walls and bed. The dry wall 
forming the npper face of the dam was so laid as to embed in its surface a 
series of redwood timbers, 6" X 6" in size, placed in vertical parallel lines, 
S feet 4 inches apart between centers. These timbers projected 2 inches 
beyond the face of the wall, and the planks were spiked to them. As each 
TOW of plank was pat in position, beginning at the bottom, concrete was 
rammed into the 2-inch space between the plank and the face of the wall, 
giving a full bearing for the plank thronghont. This provision was 
certainly a wise one, and so far as the writer is informed was never employed 
before in the dams of this class previously coustracted. On the lower third 
of the dam the facing plank are 3 inches thick, on the middle third 
H inches, and on the upper third 1^ inches, all being doubled throughout. 
Joints were broken as far as possible, both at the vertical and the horizontal 
fieams, by the second layer, and they were calked with oakum and smeared 
with hot asphaltum. 

Springs of water were developed in the excavation of the foundation to 
the extent of 30,000 to 40,000 gallons per day, constant flow. These were 
led oat by pipes to the outer toe. The leakage through the dam when 
filled to the 47-foot level was found to be 130,000 gallons daily, exclusive 
of the springs. This increased to 450,000 gallons daily when the reservoir 
filled to the top. It is not known whether this leakage comes through the 
joints of the facing or percolates through the disintegrated granite beneath 
the dam. Whatever may be its origin, it is entirely harmless as far as can 
be observed, and is not a source of anxiety. In the winter months when 
irrigation is not required this leakage-water is used for domestic service, 
and the whole of it is at all times picked up by the diverting-dam and 
carried into the distributing system. Hence it occasions no direct loss of 
water. While this amount of leakage would be dangerous to an earth dam, 
and even in a masonry structure would indicate the existence of an upward 
pressure that might endanger its stability if the section were too light, yet 
in a work of this nature the drainage through the open, loose rock is so 
perfect that the gravity of the mass is not lessened or disturbed by it, and 
no serious consequence can be anticipated. 

The facing-planks have been carried up 3 feet higher than the top of 
the rock-fill as a wave protection, so that the extreme crest is 9 feet above 
the floor of the spillway as shown by the section illustrated in Fig. 6. 

The outlet was originally designed to be controlled by means of a tower, 
the foundations of which were laid at the upper toe of the dam near the 
£outh end, but the plan was changed and a grating placed over the base of 
the unfinished tower a few feet above the gate covering the outlet. The 
gate is of cast iron with brass facings, set in a frame, also faced with brass, 
and bolted to the cast-iron outlet. It is set at the incline of the upper 
slope and is controlled by a long rod resting in guides at frequent intervals. 

Fio. «.— Plans ai.d Pbofiles op Eecoi 



fastened to the wooden facing, and leading to a vorm-gear placed at a cod- 
Tflnient height above the top of the dam (Fig. 7). The ontlet-pipe is 24 
inches in diaineter, consisting of a cast-iron elbow connecting with vitrified 

Fis. 7.— Details of Gate of 

lever-pipe of ordinary weight, laid in a trench cut in the bed-rock and 
embedded in concrete, which coven it fully 13 inches in depth. 

The total cost of the dam nnder the contract was $86,946.31, or $37.8% 
per acre-foot of reservoir capacity below the spillway level. The land for 


the site coat io additioD 123,112.88, inclndiDg clearing. The total coat 
was therefore $110,059.09, or $38.41 per acre-foot o( capaoitj. The 
prices paid were nausaally high for each work, and were the following per 
cabic yard: earth excavatioD, 30 cents; rock excavatioo, (1.10; rock-fill, 
11.50; dry etone masonry, $3,75; rabble maaonry in cement mortar, $8; 
concrete, $14; lamber, $50 per thousand feet board measure. 

The detail of thia work is given with special fnllnoBs, as it is the first 
Tock-fiU dam to be constructed in California for irrigation storage, and is 

of a type which is likely to be employed quite commonly in the fatare in 
localities better adapted for its nse than in this particular case, where stone 
was comparatively scarce in the immediate vicinity of the dam. 

The Sistribnting System. — Owing to the rolling character of tlie topog- 
raphy over a considerable portion of the Escondido District the system of dis- 
tribution of water necessarily consisted largely of pressure-pipes, alternating 
with ditches and flumes. Water is released from the dam into the rocky bed 
of the canyon in wbicb it flows for half a mile to a small masonry weir, built 
on solid bed-rock, illustrated in Fig. 8. The main conduit heads here with 
a flume, having a capacity of 30 second-feet. The laterals leading from 


this condait have capacities of from 1 to 10 second-feet. When completed 
in 1895 the distribating system consisted of 14.5 miles of riyeted steel pipes, 
3 to 20 inches in diameter, 2 miles of flames, 1.5 miles of vitrified clay and 
cement pipes, and 13.5 miles of open ditches in earth — ^a total of 31.5 miles. 
Daring 1897, '98, and '99 aboat 11 miles of the open ditches in earth have 
been lined with cement to prevent loss of water by leakage; 4^ miles of 
vitrified pipe from 5 to 14 inches in diameter have been laid, also 1.15 miles 
of 4- and 6-lnch cement pipe, 0.87 mile of 2-, 3-, and 4-inch iron pipes, 
and 0.16 mile of 8-inch wood pipe. In addition to this are 15 miles of 
2- and 4-inch pipes that formed the domestic-supply system of the town 
of Escondido, which is a part of the irrigation district, and is provided with 
domestic water by the district in the same proportion as a similar area of 
farming lands. This town-distributing system was in private ownership 
prior to the organization of the district, and was supplied by wells and 
pumps. It was purchased by the district for 19000 in bonds, and there 
was included in the purchase a lined and covered reservoir of 800,000 
gallons capacity, a Worthington steam-pump of 500,000 gallons daily 
capacity, three 20-foot brick-lined wells, 20 feet deep, and twenty 2-inch 
driven wells, all connected by suction-pipes to the main pump. This 
auxiliary pumping supply, though small in amount, is very convenient to 
draw upon for domestic service in the late summer and fall when the water 
in the reservoir becomes foul and unfit for domestic use. The entire first 
cost of the distributing system was t85,727.80. 

The works of the district summarize in cost as follows: 

Main feeder conduit $116,328.60 

Dam and reservoir 110,059.09 

Distribution system 85,727.80 

Total $312,115.49 

The first issue of bonds by the district, out of the total amount of 
1350,000 authorized, was $344,500, which realized in cash or its equivalent 
$313,750, all of which was expended on first construction. The proceeds 
of the remaining $5500 of bonds, together with $2500 additional raised by 
taxation, were expended in the early part of 1897 in lining the main dis- 
tributing ditches with cement plaster. 

The irrigators using water in 1897 were 225 in number, cultivating 
1575 acres, chiefly planted to citrus fruits. In addition to these the taps 
on the distributing system in the town numbered 204. 

The annual expense of operating the system, is about $4000, while the 
interest on the bonds at 6^ amounts to $21,000 per annum. The bonds 
run for twenty years, but their retirement begins on the tenth year from 
their issuance, and are payable thereafter at the rate of one-tenth each year. 
The total annual expense for salaries and interest divided by the number of 













acre-feet of reaerroir capacity bringg the annnal cost per acre-foot of avail- 
able water to about t8. Taking into accoant, however, the Iobscb bj 
evaporation in the reservoir and leakage from the ditchea and flames in 
traneit:, the cost of water actually available for nae on the lands is not far 
from tlS.SO per acre-foot, or nearly 4 cants per 1000 gallons. The svsntge 
reqairemeotforadeqaate irrigation is estimated at abont 1^ inches in depth, 


or 1 acre-foot per acre. At this rate the district when fully irrigated would 
need 13,000 acre-feet, or nearly fonr times the present capacity of the 
reservoir. The total annnal expenses divided by the total area of the 
district gives an average of about 11.80 per acre. The assessed valuation 
of the district in 1807 was *677,50O, and the tax-rate assessed by the direct- 
ors for irrigation expenses was $3.60 per $100. As the best land wa£ 
i at t40 per acre, it was shown on that basis that the average cost to 


the ow^ner was bat $1.48 an acre, which is a low rate, provided the payment 
of the tax wonld iasare him a snfficieafc sapply for the irrigation of hi^ 
land; but as the provision thns far made for the district in water-supply is> 
less than one-fourth of what will ultimately be required to irrigate the 
whole district, and as the water available is apportioned to the irrigator pro 
rata to the amount of tax he pays, his annual rate must necessarily be 
higher than the amount stated if he receives the water he actually requires. 

The apportionment is made in regular runs, once each month, beginning 
at the head of the system, and in order to accomplish the satisfactory irri- 
gation of their tracts the orchardists are obliged to buy what water they 
lack of full supply from such of the neighboring taxpayers as do not yet 
use the water to which they are legally entitled. This assigned water is 
sold at about 10 cents per miner's inch for 24 hours' run, which is about 
one-third cost. During 1897 the water thus transferred was about 9488 
inches for 24 hours. A toll of 1 cent per 24-hour inch, or 25 cents as a 
minimum, is charged as a gate-tax for zanjero's* fees for turning water on 
and off, which brings in a revenue of about $80 per month during the 
irrigating season, and $60 per month during the rest of the year. This toll 
was increased in 1899 to 40 cents, which covers all costs of operating. 

The selling-price of water has steadily advanced daring the late years of 
drought. In 1897 it was sold at 5 to 20 cents per miner's inch for 24 hours 
(12,960 gallons). In 1898 the rates were increased to 25 to 35 cents per 
inch, and in 1899 they were 50 to 60 cents per inch. The catchment of 
the reservoir has been approximately as follows: 

1895, 48 feet depth = 880 acre-feet 

1896, 60 '' " = 1925 " 

1897, 74 " *' = 3700 " , 
1§98, 59.5 '' " = 1000 " 

1899, 47 " " = 830 ** 

Total 8335 acre-feet, or an average of 1667 per annum. 

A large number of orchards had been started and were being irrigated 
by water pumped from wells by windmills and gasoline engines before the 
completion of the works of the district. The cost of pumping by the 
various methods employed ranged from 3 to 8 cents per 1000 gallons ($10 
to $26 per acre-foot), and this high cost, coupled with a very moderate and 
inadequate supply, caused many of the landowners whose property was not 
incorporated in the district to seek admission on equal terms with those 
inside. Several hundred acres were thus taken in after the works had been 
completed to the present stage upon payment of all back charges pro rata. 

* From the Spanish, meaning ditch-tender. 

Fio, 10a.— Ehcundido (Cal.) ICock-f 




The residents of the district realize that their works are la an incomplete 
stage, and that to secure an adequate supply it is necessary to carry the 
storage-dam 40 feet higher, giving it a capacity of 11,355 acre-feet. This 
can readily be done at a cost not to exceed $110,000. The land purchased 
for the reservoir covers the enlarged area proposed, and it is only necessary 
to continue the embankment higher, adding the necessary width of base to 
give the same safe slopes which the present embankment possesses, and 
extending the wood-facing. With this improvement, and the addition of 
the smaller regulating reservoir on the river before mentioned, it is believed 
that the district will have an ample supply for its needs at a total outlay of 
about $40 per acre, and an average annual expense of $2.50 to $3 per acre. 

During the fall of 1897 the validity of the bond issue was questioned by 
a portion of the landowners, many of whom ceased paying the tax levied 
to meet the interest on the bonds. In March, 1899, the bondholders 
requested the trustee, the Farmers and Merchants' Bank of San Diego, to 
take charge of the system according to the terms of the trust deed, and as 
provided by the Wright Act under which the district is organized. This 
was done, and the former superintendent was continued as manager. 

Lower Otay Bock-fill Steel-core Dam, California. — One of the most 
interesting of all the rock-fill types of dam yet constructed is located on 
Otay Creek, San Diego County, California, 22 miles southeast of San 
Diego, 10 miles back from the coast, and not more than 5 miles from the 
Mexican boundary-line. It forms the lower one of a series of four 
mammoth dams projected by the Southern California Mountain Water 
Company, to impound water for the municipalities of San Diego and 
Coronado and for the irrigation of an extensive area of f restless mesa lands 
adapted to citrus-fruit culture, reaching from the Mexican border north- 
ward to San Diego, including the peninsula of Coronado, and for the 
domestic supply of the villages and towns within reach of the distribating 
system to be built from the reservoir. This system of reservoirs and 
conduits is the most comprehensive one yet projected in California for 
irrigation purposes, and when completed in its entirety it must add so 
greatly to the productive area and population of the region in the vicinity 
of the Bay of San Diego as to bring that port into the prominence in the 
world's commerce which its general excellence as a harbor has long deserved. 
The Lower Otay dam was completed in August, 1897, and the Morena and 
Barrett dams, the other two of the series, have been under construction 
since that time, although both are still far from completion. 

The Otay Creek, at the point selected for the dam, cuts through the 
great dike of porphyry which traverses San Diego County from north to 
south nearly parallel with the coast-line. This dike in places is 10 miles 
or more' in width, and at others less than 1 mile, and occupies the middle 
ground between the granite formation lying east of it, and the mesa forma- 


tioD, wliicb is an irregular strip of land, 10 to 15 miles wide, lying between 
the porphyry dike and the shore of the Pacific. The mesa formation is 
alluvial iu origin; consisting of marl, indurated sand, gravel, cobbles, and 
all shades of soil from clay to sandy loam, but is devoid of hard rock, while 
the porphyry is an igneous rock, exceedingly tough, of high specific 
gravity, without regular cleavage, but broken by numerous fine seams wich 
infiltration of reddish clay. The highest protrusions of the dike form the 
San Ysidro and San Miguel mountains, 2500 to 3000 feet in altitude. It 
is intersected by all the streams of the county that reach to the ocean, 
affording sites for the Lower Otay, the Upper Otay, the Sweetwater and 
La Mesa dams, and others further north that are projected. The Escondido 
dam is but a mile or two eai^t of the dike in granite formation. The Otay 
dam is within a few hundred feet of the western limit of this dike, and in 
fact the outlet tunnel of the reservoir avoids it entirely and was excavated 
through the soft brown marl of the mesa formation. 

The site of the Otay dam was an ideal one for a ma£onry structure, 
because of the satisfactory character of the bed-rock foundations, and the 
abundance of suitable rock and sand at the site, while its convenience to a 
port of entry rendered the cost of cement very moderate. The usual 
incentive for building rock-fill dams iu preference to masonry, due to their 
remoteness and the high cost of freighting cement to the site was lacking 
in this case, and in fact the work was originally planned as a masonry dam. 
A foundation was laid for this purpose 65 feet thick at the base, reaching 
down to a depth of 31.4 feet below zero contour, and carried up to a height 
of 8.6 feet above zero, with a length on top of 85 feet. A view of the work 
is shown in Fig. 11. 

Whether the change in plan from masonry to rock-fill with steel core 
has resulted in economy of first cost is difficult to determine, as the actual 
cost of construction has not been made public, or whether there may be 
grounds for regret that the change was made cannot be known until the 
stability of the structure is fully tested by the lapse of time. The reservoir 
has never filled above the 60-foot contour since the completion of the dam 
np to the fall of 1900, and nntil the reservoir is filled and remains full a 
considerable period without developing signs of weakness or extensive 
leakage the success of the novel design cannot be known. Meantime the 
engineering profession will entertain the liveliest interest in the develop- 
ment of this novel type of dam, which, if successful, will certainly have 
wide application to other sites where the choice of material has a more 
limited range. The credit for originating the idea of making a rock-fill 
dam water-tight by inserting in its center a web-plate of steel, filling the 
entire cross-section of the canyon from side to side, and for putting it in 
application on a large scale, belongs to the president of the water company, 
Mr. E. S. Babcock, of Coronado. Wiien this plan was decided upon a 


heavy T iron was anchored to the top of the finished masonr; foaadation 
by l-inch bolts, set in the masonry. The vertical leg of the T vas panched 
Tith ^-inch rivet-holes, spaced 3 inches center to center, and the bottom 
plates riveted to it. The plates were 5 feet wide, and 17.5 feet long, and 
the three bottom coaraes were 0.33 inch thick. From 28 to SO feet high 
they are ^ inch thick, and above 50 feet they are 8 feet wide, 20 feet long, 
and lessening in thickness as the top is approached. After riveting the 

Pio. 1 1 — Mabosbt FonNDATioH OF Lower Otay Dam. 

plates together with hot rivets they were chipped and calked on the side 
next to the water, and coated with Alcatraz asphalt, F grade, applied hot 
with brnshes. Over this coat a layer of bnrlap was placed on each side of 
the plates, while the asphalt was still hot. This adhered tightly to the 
plate and served to hold the soft asphalt from flowing. A harder grade of 
asphalt was sabseqaently pat on over the barlap, and the whole then 
encased in a rnbble-masonry wall laid with Portland-cement concrete, S feet 
thick, the steel plate being in the centre. This wall at base is 6 feet thick, 


tapering to 2 feet in a height of 8 feet. The moalds for the concrete, con- 
sisting of 1-Jnch boards laid horizontally and 2 X 6-inch vertical posts, were 
left in position permanently and the rock-fill built against them on either 
side. The steel core, or web-plate, was carried into the side walls of the 
canyon in a trench excavated to the depth necessary to reach solid rock and 
anchored with bolts leaded into the rock. The end plates were not trimmed 
to fit the irregalar line of the rock cutting, but the masonry was widened 
to a maximum thickness of 20 feet at the sides, tapering from the normal 
thickness of 2 feet in a distance of about 20 feet. Fig. 12 shows the trench 
on the right bank about at the 40-foot contour. The function of the wall 
is to steady and stiffen the web-plate and protect it from injury from the 
loose rock piled against it, and as the wooden moulds were not removed the 
embankment is free to settle without injuring the concrete or the plates. 

The expansion of the plates after they were riveted together, and the 
obtuse angle up-stream on which they were first started, which gradually 
was obliterated by an approach to a straight line toward the top of the 
dam, gave them a very irregular alignment, as will be seen in Fig. 13, which 
is a view looking along the top of the dam toward the left bank just before 
its completion. 

The dam is a loose, rock-fill embankment, lying as it was dumped, 
without any portion of it, except the 2-foot core-wall, being laid by hand. 
In this respect it differs from its predecessors of the same type, which have 
been built with a considerable proportion of their slopes on the water-side 
laid up as a dry wall. It was designed to be 20 feet wide at top, with side 
slopes of 1^ on 1 on each side. When work was suspended the up-stream 
slope, composed of the finer grades of materials coming from the quarry, 
had assumed about the slope stated, but the lower slope was steeper and 
stands about 1 to 1, while the top width is from 9 to 12 feet. When 
visited by the writer in September, 1899, the material excavated from the 
spillway cut was being dumped on the upper slope and the top width 
increased. The spillway is located some few hundred feet from the east 
end of the dam, and will consist of a channel 30 feet wide, 300 feet long, 
with a maximum depth of 30 feet, cut in the rock to a depth of 10 feet 
below the crest of the dam. The depth of water will be controlled by 
flash-boards resting at an angle of 30^, between channel-iron frames placed 
5 feet apart. A wagon-bridge will be built over the top of these frames, 
from which full control of the flash-boards will be had. The discharge of 
the spillway will reach the creek channel several hundred feet below the 
toe of the embankment. 

The entire volume of stone used in the work, approximately 180,000 
cubic yards, was qaarried immediately below the dam on the right bank, 
and was transported from the quarry by means of a Lidgerwood cableway, 
the cable having a diameter of 2:^ inches, and a span of 948 feet between 

Tia. IS. — Steel Wrb-plate and Aiiniiou-TitENCH at Wbst End ok Lowur Otaj 


towen, crosaiDg the canyon diagonally, at an angle of abont 60° with the 
■xie of the dam. The head tower was 130 feet high, the tail tower down- 
stream 60 teet high, the tops being practically level, and a direct line 
between them crosaed the axis of the dam 260 feet above the bed of the 
stream. The cableway had a gnaranteed capacity of 10 tons, center load, 
ander which its deflection was S8 feet, or 43 feet higher than the top of the 

Fio. 18.— Crest of Lowbu Otat Dam, snuwiNa Wkb-plate of Sti 
i.v CoNCRBTE. Dam NEARiMo Completion. 

dam. Up to the height of 75 feet the rock damped nnder the line of the 
cable was distribated by means of derricks, hot aabsequently a secondary 
cableway was erected parallel with the line of the dam, underneath the 
main cable. This was anchored at each end to heavily ballaeted cars rest- 
ing on tracks, which permitted the cable to be shifted 30 feet, or 15 feet 
either side of the center of the dam. The loaded skips from the qnarry 
brought to the dam by the overhead cable were picked np by the secondary 
cable and carried to any point desired along the line of the dam. Tools, 
materials, derricks, 35-n. P. hoisting-eDgines, and all other articles required 


Fio. 14. — Map of Lower Otat Reservoih. 


to be moved from one position to another were hauled rapidly and safely by 
means of these cableways, and not infrequently the employees preferred the 
aerial jonrney across the canyon by the cableway to the more laborious 
climb over the trails. Fig. 15 illustrates the general plan of the dam, with 
a cross-section of the site and details of the outlet tunnel. 

Quarry, — All or the greater portion of the rock had been loosened in 
the quarry by very heavy blasts, the first of which was made by driving a 
tunnel 50 feet into the face of the cliff with lateral drifts, 18 and 28 feet 
long respectively. In the shorter drift, 4000 pounds of Judson powder 
(containing 6% nitro-glycerine) under a vertical depth of 70 feet, and in the 
larger, 8000 pounds under a depth of 85 feet, were exploded simultaneously, 
which resulted in loosening and throwing out about 50,000 to 75,000 cubic 
yards. A view of this blast taken at the moment of explosion is shown in 
Fig. 16. The second large blast was prepared by sinking a shaft 115 feet 
deep, 85 feet back from the nearly vertical face left by the first blast. At 
a depth of 50 feet two drifts were run laterally a distance of 25 feet each, 
and at the bottom of the shaft two more drifts, 30 and 35 feet long respec- 
tively, were extended into the rock toward the face and in the opposite 
direction, and the four holes thus prepared were loaded with 30,000 pounds 
of powder, of which the greater portion was located in the bottom drifts. 
This blast did greater execution than the first, and supplied sufficient rock 
to complete the dam. Minor blasting of the ordinary class was necessary 
throughout the work to break up the larger masses to sizes that could be 
handled by the cableway. The quarry being near the lower toe of the dam, 
the first large blast filled in the toe with large bowlders, some of which 
weighed upwards of 50 tons, and a subsequent freshet, pouring over and 
through these rocks, scoured out the sand beneath them so as to settle them 
well to bed-rock, which was a fortunate occurrence. 

The watershed of Otay Greek above the reservoir is about 100 square 
miles in area, but as its average altitude is not over 1600 feet the precipita- 
tion is light and the run-off insufficient to fill the reservoir except in occa- 
sional years. In dry seasons there is no flow whatever. The catchment in 
four years prior to September, 1899, has not exceeded 5000 acre-feet. To 
make up for this shortage in supply and to fill the reservoir regularly the 
company is planning to divert water from Cottonwood Greek, a stream 
adjoining on the south which drains an extensive region of the highest 
mountains of the main range. This stream enters Mexican territory and 
returns again, emptying into the sea near the boundary-line, where it is 
known as the Tia Juana River. The conduit for diverting its flow will 
start at the second reservoir of the system, known as the ^^ Barrett dam," 
at an elevation of 80 feet above the stream-bed, or about 1650 feet above 
sea-level, and be supported along the southerly slopes of Lyon's Peak to 
Dulzura Pass, where the divide will be crossed by a long tunnel, from which 

Fio. 15. — Pi-AHs OK LowRD Ot&t Rebbrvoir. 


the water will drop into the east fork of Otay Creek and thence to Otaj 
reservoir. The condait will be a trifle over 8 miles in length, and consist 
of a saccession of cement-lined tunnels in granite. To regulate the flow of 
the stream and store additional water the company have under construction 
two dams of mammoth size — the Barrett and Morena, both of which have 
been projected as rock-fili dams. 

Outlet Tunnel, — ^There are no pipes or outlets through or under the 
dam proper, and the only outlet provided is a circular tunnel through a 
narrow part of the enclosing ridge 1000 feet west of the dam. This tnnnel 
is 1150 feet long, the bottom of which is at the 48-foot contour. Below 
the tunnel-level, therefore, as will be seen by reference to the table of reser- 
voir capacities in the Appendix, there remains a volume of water of approxi- 
mately 2000 acre-feet (652,400,000 gallons), covering nearly 160 acres of 
surface which can never be drawn off. The material encountered in this 
tunnel was a brown hard-pan, resembling marl, and cemented gravel, both 
bone-dry. The western limit of the porphyry dike is between the tunnel 
and the dam. For 500 feet from the inner heading the tunnel was lined 
with concrete to a clear circular diameter of 5 feet, the lining being 12 to 
18 inches thick and plastered with cement mortar. At the end of this 
section a shaft, 104 feet in depth, reaches to the surface. Below this shaft 
a 48-iuch riveted steel pipe is laid to the outside, and the entire annular 
space between the pipe and the walls of the tunnel is filled with concrete, 
with a minimum thickness of 12 inches. This pipe was put together in 
sections of 38 inches in length, stovepipe fashion, the insertion at each 
joint being 2 to 3 inches. The joints were driven as closely as possible, but 
owing to the sag of the pipe and the absence of careful ramming of the 
concrete at the bottom of the joint it was found on completion that there 
were cavities which rendered it impossible to calk the joints from the inside 
and make them water-tight. As it was desirable to utilize the full depth 
of the reservoir pressure on the condait outside the tunnel, it was essential 
to stop the leakage in the pipe lining of the tunnel, and a plan has been 
devised by H. N. Savage, M. Am. Soc. C. E., consulting engineer of the 
company, to do this by means of threaded '^ patch-bolts," tapped into the 
joints at intervals of 3 inches, thus drawing the plates together. When 
this is done cement grout will be pumped into the cavities at one of the 
bolt-holes, an inside band will be inserted covering the heads of the patch- 
bolts, and the space filled with cement. It is expected that the device will 
prove successful. At the upper end of the tunnel a balanced valve will 
control the admission of water, and additional control will be snpplied by a 
gate-valve in the pipe at the tunnel-outlet, and a gate-valve operated from 
the shaft at the junction of the large and small sections of the tunnel. 
The location of this tunnel-outlet through the hill saved a mile or more of 
pipe-line through the canyon from the dam, although the latter might have 


been cheaper. The main condait from the reservoir to San Diego will con- 
sisfc of steel and wood-stave pipe, from which the intermediate lands will be 

The Barrett Dam. — The middle one of the chain of three great resenroirs 
under constraction by the Sonthern California Mountain Water Company 
is located aboat 40 miles southeast of San Diego, and about 6 miles north 
of the Mexican boundary, at an altitude of about 1600 feet. It occupies a 
singularly valuable strategic position, as it is the lowest feasible reservoir- 
site on the stream from which water can be conveyed by gravity conduits 
without passing through foreign territory. It is also at the lowest elevation 
from which water can be distributed to the most valuable mesa lands 
adjacent to the coast, and at the same time it is low enouorh on the stream 
to receive the run-off from the greatest area of mountain watersiied avail- 
able for any reservoir in southern California. This area is about 250 square 
miles. The precipitous and rocky character of this watershed insures a 
maximum average run-off and catchment in years of normal precipitation. 

The dam- and reservoir-site were acquired by the San Miguel Water 
Company, a local organization, in 1889, and subseqaently transferred to the 
Jamacha Irrigation District, organized under the Wright Law of California, 
for the consideration of $105,000 of the bonds of the district, the purchase 
including 560 acres of land and certain water-rights. The district has 
taken no steps to construct the dam and conduit by which alone the 
property would have value, other than to contract with the Southern 
California Mountain W^ater Company for its water-supply, and the latter is 
now engaged in constructing the dam. In 1897 the company erected a 
masonry dam, shown in Fig. 17, 72 feet»in height from its base, which is 
22 feet below the stream-bed, to its top 50 feet above. This structure rests 
on solid granite bed-rock throughout, and is 14 feet thick at bottom, 5 feet 
at top, and aboat 30 feet long on the crest. This was to be used simply as 
a pick-up weir to divert water into the Dulzura pass conduit. Subsequently 
it was decided to build a storage dam, similar in plan to that of the Lower 
Otay, to an extreme height of 175 feet, and a new location was chosen 
about 1000 feet further down stream, where rock could be more con- 
veniently obtained for a rock-fill structure. Here a new masonry dam was 
built in 1898, reaching to bed-rock in the stream-bed and extending about 
35 feet above, upon which to begin the sheet-steel core of the rock-fill 
The dimensions were as follows : 

Length on top 115 feet. 

Thickness at base 30 " 

Thickness at top 13 " 

Its cubical contents are 3100 cubic yards, and there were consumed in its 


constraction 1777 barrels of cement An outlet tunnel, 8x8 feet in size, 
600 feet long, has been excavated in solid rock on the right bank, at a 
height of 80 feet aboTe the stream, which is the beginning of the tunnel 
conduit to Dnlzura Pass. Actual work upon the rock-fill portion of the 
dam has not yet begun, and it is possible that the plans may yet be recon- 
sidered and a masonry dam substituted for the rock-fill, out of deference to 
the torrential character of the stream in seasons of exceptional rainfall, and 
the possible risk involved in a rock-fill on such a stream during construc- 
tion and subsequently. The vast importance of this structure as the key 
to ^the entire system, not only for storage but for the diversion of water, 
doubtless emphasizes the necessity for unquestionable stability, and suggests 
the wisdom of relying upon masonry. It cannot be claimed for rock-fill 
dams that they are inherently superior to masonry or concrete structures of 
heavy gravity section, and they are only to be preferred as a substitute 
where natural conditions render them very much cheaper, and hence prac- 
ticable for nse in cases where the greater cost of masonry would be prohibi- 

Watershed, — The tributary watershed ranges in altitude from 1600 to 
6000 feet, and probably averages 3600 feet. The mean precipitation on this 
slied may ordinarily be expected to be from 10 to 20 inches greater than 
that of San Diego, from the natural increase due to altitude, and in some 
years it may be 30 to 35 inches greater. The mean precipitation of San 
Diego for 40 years from 1850 to 1890 was 9.86 inches, ranging from 3.02 
inches in 1863 to 27.59 inches in 1884. To fill the reservoir to the 175- 
foot contour will require 47.970 acre-feet (20,900,000,000 cubic feet) which 
would be supplied by an average run-off of 3.6 inches from the watershed. 
Under unfavorable conditions this depth of run-off would be expected from 
an annual rainfall of 24 inches, and may at times be the product of but 15 
inches' precipitation, depending largely upon the distribution of the storms, 
and the frequency with which they succeed each other. In years like 1884 
or 1895 the run-off may be as great as ten times the capacity of the 
reservoir, and the maximum spillway capacity to be provided may reach 
40,000 second-feet. 

Morena Rock-fill Dam. — The third great reservoir of the Southern 
California Mountain Water Company is located 10 miles east of the Barrett 
dam, on one of the two streams that unite just above Barrett, at an altitude 
of 3100 feet above sea-level. It is 50 miles from San Diego, and 7 miles 
north of the international boundary. The dam is a rock-fill structure, 
placed in a narrow canyon, cut through massive granite cliffs that tower 
hundreds of feet high, on the brink of a precipitous fall or cataract, where 
the stream takes a plunge of 1200 to 1300 feet in a mile of distance. This 
canyon is filled with enormous bowlders throughout, and at the site of the 
dam the narrow fissure eroded by the stream was found to be more than 


100 feet deep below the stream-bed. Fig. 18 is a view taken of the dam- 
site looking ap stream, and well illnstrates the character of the rock-masses 
filling the gorge. The tree growing at the right of the picture is on the 
line of the masonry toe- wall. This wall was carried down to the bottom of 
the fissure, 112.5 feet below the general stream-bed at that point. This 
wall is at the upper toe of the rock-fill, and is 36 feet thick at the bottom, 
where the width between solid walls was but 4 feet for a height of 12 feet. 
The widest part of the fissure was 16 feet, and at the zero contour it was 
80 feet wide. At this point the thickness of the masonry was made 20 feet. 
It was carried up 30 feet higher, where the thickness is 12 feet. The top 
of the wall is shown in the view of the partially finished dam (Fig. 19) just 
abore the water-line. The upper toe of the rock-fill, which will be finished 
on a slope of 1^ to 1, will reach to the top of this toe-wall, and will be 
covered with 5 feet of Portland cement, uncoursed rubble masonry, over 
which it was intended to lay a sheet of asphalt concrete, 12 inches tbick at 
base and 4 inches thick on top, extending into a groove moulded in the 
wall, 5 feet in depth. The plan for using asphalt concrete has been 
abandoned recently and some other material will be substituted. The rock- 
fill, as shown by this view, is about 80 feet high above the wall. 

The canyon walls are of clean, hard granite, singularly free from fissures 
and seams. The width between tbem is but 80 feet at the stream-bed and 
470 feet at the height of 160 feet above. The sides thus have a slope 
steeper than 1 to 1, or about 41° from the vertical. Had the planes of the 
side slopes continued beneath the surface the maximum depth to bed-rock 
would have been but 30 feet instead of 112.5 feet where it was found. The 
situation is a favorable one for any type of dam, except eartli, and especially 
favorable for a masonry structure, although the freighting of cement to the 
site would have made that class of work more costly than at the Lower 
Otay. Work was begun in the summer of 1896, and by the fall of the fol- 
lowing year the rock-fill had reached a height of 80 feet above the top of 
the toe-wall, when work was suspended. The ultimate height to which the 
dam is designed to be carried is 160 feet, to hold a maximum depth of 150 
feet of water, and impound 46,733 acre-feet (20,360,000,000 cubic feet). 
The volume of rock in the structure, computed on slopes of 1 to 1 on the 
face, and 1^ to 1 on the back, will be approximately 400,000 cubic yards. 
If the face is given a slope of 1^ to 1, the volume will considerably exceed 
this amount. The thickness at base is over 800 feet, while the extreme 
height of rock-fill from the lower toe down the canyon will be in excess of 
250 feet. Large blasts were employed in loosening the rock for the dam in 
a similar manner to the method used at the Otay dam, with the exception 
that the quarries were located on each side of the canyon above the top of 
the dam, in such position that much of the rock was thrown down in place 
thereby and did not subsequently require removal. Bowlders weighing 


hnndnds of tons were thoB deposited in the bed of the canyoQ and on its 

The flnt blast of 100,000 Iba. of powder, exploded December 26, 1896, 
wu efltimsted to have moved 75,000 oabic yards. A aecoDd blast, fired fire 
days later, with 80,000 lbs., did good ezecation, and on March 24, 1897, 
the ezploeion of 70,000 Ibe. is reported to have loosened 100,000 tons. 

The machinery assembled for the constraction is said to have coat 
tl 75,000. Two lines of Lidgerwood cableway span the chasm at a height 
of 400 feet, operating from the qnarries on either side. These csbleways 
are attached to heavily ballasted cars, sapported on three lines of railway- 
track on either side, with a range of movement of 100 feet each, parallel 
with the axis of the dami Powerful derricks of the moat improved types 

liave been placed in convenient position, and no less than twenty hoisting- 
engines have been assembled for the work. 

Outlet. — The water is to be drawn from the reservoir through a tunnel, 
600 feet long, cut in the granite on the south side ai the 30-foot contour, 
the dimensions of which are 8 x 8 feet. This tunnel is to be controlled by 
a series of balanced valves to be placed at the reservoir end, while the water 
ia to be discharged into the canyon and flow down the channel to the 
Barrett reservoir below. 

Waterslted. — The area of drainage intercepted by the dam is 130 square 
miles, or rather mare than half of that tributary to the Barrett, of which it 
ia a part, and ranging in altitude from 3200 to 6000 feeC, averaging about 
4000 feet. Both reservoirs cannot be expected to fill every year, although 
there are frequent seasous when the run-oS will sarpasa the capacity of all 


tbree reservoirs in the sjitem. By proriding ample storage and holdiog^ 
over a large earplns ever; year, the masimam duty can be obtaioed from 
the tribatary streams. 

Conditions of Construction. — The dam ia beiog bailt nnder a oontract 
with the city of San Diego by which the compaay nDdertakes to deliver 
1000 mioer's inches continaoas flow (13,960,000 gallons daily), at a point 
designated as the '' Meter>house Site," abont II miles southeast of the 
nearest limits of the city, for the snm of 1727,000. This is to be accom- 
plished by the conduit from the Barrett dam to Dalznra Pass, 9.5 miles in 
length, which is to have a large snrplns capacity for conveying water to the 
Otay reservoir, and by a continnation of this coadait of smaller capacity a. 


distance of 26 miles farther, from the Dalznra Pass to the Meter-honse 

Between the oatlet level and the 130-foot contonr the reservoir has a 
capacity sofficiently in excess of the agreed amonnt required to supply 1000 
inches flow for one year to cover probable loss by evaporation, and under 
the contract so much of the reservoir up to the 120-foot contour is to be 
conveyed by deed to the city, while all the land above the 120'foot level is 
to be reserved by the company, together with the privilege of building the 
dam to a greater height, thus storing water for its own use and for sale to 
other parties on top of the city's reservoir. The addition of 30 feet will 
increase the capacity 200^, giving the company about 30,000 acre-feet of 
water. The watershed area above the dam as before stated is about 130 


sqasre milee, from which a ran-oS of 30^ of 33 iacbes of raiufall ironld 
eaffice to fill the reserroir. 

Work upon the reserroir has beeu scBpeiided pending the ontcome of 
protracted litigation over the Tsliditj of the contract between the city 
council of San Diego and the water company, and the validity of the city 
bonds Tot«d far the water-works.* Meantime it is nnderstood that the 
Barrett dam is to be completed, and the condnit to Dnlzura Pass and 
beyond, by which the com[«ny will be enabled to utilize ita system for irri- 
gation independently of the water-supply of San Diego. 

The entire system is the most comprehensive storage enterprise yet pro- 
jected in California for the utilization of water that normally flows to the 
sea unemployed and useless. Its completion will be an important factor 
in the development of a portion of the frostless area of southern Califoraia. 

The Upper Otay Dam. — This structure, which is a part of the general 
system just described, is on the West Fork of Otay Greek, and is at such 
an elevation that the high-water line of the Lower Otay reservoir will touch 
the base of the dam of the Upper one. The dam-site is in a porphyry-rook 

Fia. 21.— REsuRvoiRa near 8an Diego, Califokma. 

gorge, where the width between walls at the stream-bed is but 20 feet. 
The supporting hills fall away quite rapidly, however, go that at the CO-foot 
contour the width is 316 feet, and at the 130-foot contour it is 1060 feet. 
The dam baa been started as a masonry structare and carried to a height of 
34 feet, but as the watershed directly tributary is but 8 square miles, and 
the capacity of the reservoir quite limited (15,342 acre-feet), as compared 
with the Lower Otay, its completion and nltilization as a storage-reservoir 
will be independent of its own local water-supply. The masonry wall 
already laid has a length at bottom of bat 12 feot, and is bat 75 feet long 

* This coDiract has reMOtly boeo declared void, tlie Supreme Court of Ckliforala 
Iiftvlog decided tlikt the election for the bonds voted by the City wis illegd and invalid. 


on ita preaent crest. The height is to be materially increased in the near 
fiitare if the plans of the compacy are not changed, sad it may become a 
stTDctnre of considerable magnitude. 

ChativoTth Park Rook-fill Dam. — A stractnre of more than common 
interest aa an example of " how not to do it" was erected on Mormon 
Canyon, in the westerly part of San Fernando Valley, Los Angalea Co., 
California, near the station of Gliatsworth Parli, in the winter of 1895-9D, 
for impounding water for irrigation and to serve as a diverting-dum for a 
conduit to carry the flood-water of the stream to a secondary reservoir of 

Fig. 32. — Upper Otat Dam. Foundation Mabonrt. 

mnch larger capacity a short distance away to the Bonth, Two failures of 
earth dams erected at the same site had already occurred prior to the build- 
ing of the dam in question, both having been overtopped and carried away 
by reason of insufficient spillway capacity. The last one was swept out 
shortly before beginning work on the rock-fill, chiefly as the result of bad 
management. The spillway had been filled with sand-bagB to make the 
reservoif hold a little more, and when the flood came there was no one at 
hand to remove them. When the attendant flnally arrived the elaice-gnte 
was stuck fast and could not be opened, and before any relief was afforded 
the water rose over the top of the dam and washed it away, althongh it was 
a well-built structure. 

The rock-fill dam was bnilt 41.33 feet high above the creek<bed, 10 feet 


wide on the top, with sides sloping at an angle of 60^, above and below 
alike, or 1 yertical to 0.57 horizontal, which gare a base width of 60 feet. 
The length on bottom is 100 feet, and at top 159 feet; cubical contents, 
6.025 cubic yards; area of water-face 7700 square feet, covered with 
Portland-cement concrete from 8 inches thick at top to 16 inches at bottom. 
The rock used for the fill is a soft sandstone, quarried on the line of the 
dam at one end, 500 feet away, and 75 feet to 100 feet higher than the top 
of the dam. The quarry-face was 30 to 40 feet high. A light trestle was 
built on a sharp incline from the quarry to and across the dam, and a cable, 
passing over a drum or pulley at top and with a car attached to each end, 
was the means employed for transportation, the loaded cars fetching up the 
empty ones. The material was dumped in place promiscuously and without 
selection. Some of it disintegrated and crumbled into sand when blasted, 
hammered, or dropped from a few feet in height, and, as everything 
loosened in the quarry was put into the fill, the proportion of sand and 
earth is very large and the natural angle of repose of the mass is much 
flatter than that of rock alone, and flatter than the slopes proposed by the 
planj. The specifications required the slopes to be laid up two feet in 
thickness as a dry wall of uncoursed rubble, but this was done in such an 
indifferent manner that within two weeks after the contractor had moved 
off the work more than three-fourths of the lower face-wall fell or slid 
down, followed by some of the embankment behind it so as to leave the 
concrete facing unsupported and its under side exppsed to view for several 
feet from the top of the dam. The dam was not of much value for water- 
tightness, as it leaked considerably with but 10 feet of water behind it. 
The work was done by contract, at a total coet of about $9000, part of which 
was payable in land. After the work was done the contractor took advan- 
tage of the failure of the company to comply with the California law 
requiring contracts to be recorded to make them valid, and brought suit to 
recover a greater amount than the contract price. He succeeded in getting 
a jury to give judgment for about 40^ additional, while the owners have 
been obliged to reconstruct the dam. This was begun on the plan illus- 
trated in Fig. 23, the lower slope being hand-laid to a thickness of 4 feet, 
and covered with a masonry slope-wall 6 feet thick, although the work is 
still incomplete. This is believed to be the first case on record of a dam 
falling down before the water-pressure had been applied to it. 

The watershed area above the dam is about 15.5 square miles, from 1000 
to 3800 feet in elevation, from which maximum fioods of 700 to 800 second- 
feet may be expected — sufficient to fill the reservoir in three or four hours, 
as the capacity is not in excess of 200 acre-feet. 

The Castlewood Dam, Colorado. — The Ohatsworth Park dam, just 
described, bears some resemblance to the Castlewood dam erected on Cherry 
Creek, some 35 miles above Denver, Colorado (which city is at the mouth 



of the same stream), althoagh the latter struct are is a much more saccess- 
ful engiueering work and of greater size aad importance. The Castle- 
wood dam was bailt in 1890 by the Denver Land and Water Company, for 
the impounding of water for the irrigation of some 16,000 acres of fertile 
mesa land lying between Cherry Creek and the Soath Platte Bi^er, and 
extending to the city limits of Denver. 

The area of watershed above the dam is about 175 square miles, from 
which the run-off after severe cloud-bursts on the ''divide" sometimes 


Fig. 23. — Sketch op Reconbtrtjction op Chatsworth Park Rock-pill Dam. 

reaches or exceeds 10,000 cubic feet per second for a short time. The 
reservoir covers about 200 acres, and has a capacity of 4,000,000,000 
gallons, or about 12,280 acre-feet. The dam is a rock-fill with a masonry 
wall on the upper face, while the lower slope is covered in steps of 2 feet 
with large blocks of stone laid in cement mortar, the general slope being 1 
to 1. The facing wall is of rough rubble masonry, 4 feet thick, standing 
on a slope or batter of 1 to 10. The two walls are joined at the top with a 
coping of large stones, forming the crest of the dam, 8 feet in width, 4 feet 
thick. The geological formation at the dam-aite J3 peculiar. The floor of 
the reservoir basin is covered to a great depth with hard, blue clay, over- 
lying which is a great sheet of sandstone and conglomerate rock or 
^' pudding-stone " 100 feet or more in thickness. The dam was founded 
on the clay, and the facing-wall was carried down into it to a depth of 6 to 


22 feet. The lower slope-wall was also foanded on this clay at a depth of 
10 feet from the surface. The general dimensions of the stractare are: 
length at top, 600 feet; extreme height abov^e floor of reservoir, 70 feet; 
height above foandation of face- wall, 92 feet; width on top, 8 feet. The 
main spillway is located in the center of the dam, and is 100 feet long by 
4 feet deep. An aaxiliary spillway, called a by-pass, is located at the west 
end of the dam, and is 40 feet in width. The total spillway capacity thns 
provided is abont 4000 second-feet, while the outlet-pipes, eight in number, 
each 12 inches diameter, have a combined capacity of abont 250 second- 

A ^' water-cushion " has been provided at the toe of the dam, to receive 
the impact of the waste water pouring over the structure and to prevent 
erosion of the toe. This is 25 feet wide, 200 feet long, and consists of a 
rock pavement, 3 to 6 feet deep, heavily grouted at the top with cement 

The face-wall has been reinforced by an embankment of earth placed 
against it, and covered with stone riprap, 1 foot thick. This embankment 
reaches to within 30 feet of the top of the dam at the outlet-tower near the 
center, and rises to the full height at either extremity. The outlet-tower 
is a rectangular structure, built in the body of the dam, with a central 
opening of 6 X 7. 5 feet reaching to the top. Into this the eight 12-inch 
outlet-pipes discharge at four successive levels, 6 feet apart from the base 
up, the gate-valves being placed inside the tower. From the base of the 
tower the water discharges into the creek channel through a 36-inch open 
pipe, made of concrete 4 feet thick, surrounding a cement pipe of standard 
dimensions. The water is picked up li^miles below the storage-dam by a 
low diverting-dam, 125 feet long, and conveyed through 40 miles of canals, 
wich maximum capacity of 75 second-feet, to the lands irrigated and to an 
aaxiliary reservoir, formed from a natural depression in the plain. This 
reservoir has a surface area of 60 acres and a capacity of 700 acre- feet, its 
maximum depth being 16 feet. 

The construction of the Castlewood dam was attended by much opposi- 
tion from the citizens of Denver, who were apprehensive of its safety and 
severely criticised the plan. Unsuccessful attempts were made to enjoin 
the construction, but it was finally permitted to be completed and has suc- 
cessfully withstood all floods to the present time. The facing-wall has 
shown no sign of settlement, but the main embankment settled a few 
inches, sufficiently to produce an unsightly crack in the center of the dam 
along the lower line of the face- wall. The coping-stones were subsequently 
relaid to true line again and no subsequent crack has developed. The 
canals and reservoirs have cost about $425,000. The dam was planned by 
A. M. Wells, C.E., of Denver, with Mr. Alfred P. Boiler, M. Am. Soc. 
C. E., of New York, as consulting engineer. Fig. 24 (taken from Engineer- 



ing Record, Dec. 34, 1898, and reprodaced by conrtee; of that jonroal) 
illaatraceB the constractioQ of tlie dam in plan, section, and elevation. 

FeoM Valley Rook-flll Damt, New Hezico. — Two rock-gll dams with 
earth faciogs have beeu constracted acrosB the Pecos River, in the Pecos 
Valley, New Mexico, which have boldly and Bacceaafally exemplitied a dis- 
tinct type of dam that is considered to be preferable to all other rock-fills 
where the proper conditioDS exidt and suitable materials are obtainable. 
One of theee danriB is located 6 miles and the other 15 miles above the town 
of Eddy, N. M. They were bnilt by the Pecos Irrigation and ImproTement 

Lake Avalon Dam. — The lower dam, designated locally as the Lake 
Avalon dam, was bnilt primarily aa a means of raising the level of water of 
the river in order to divert it into a canal at a safe height above the reach 
of maximam floods, and at the same time to eqnalize the flow by providing 

Flo. 25.— Sketch-map 

Pecos Canaii 

a considerable volame of storage in the reservoir thus created. The present 
dimensions of the dam are as follows: length on crest, 1135 feet; maximum 
height, 48 feet; enter slope of rock-fill, IJ^ to 1 ; width of rock base, 106 
feet; crown, 10 feet. The earth facing has also a crown width of 10 feet, 
making the total width 20 feet on top. The slope of the earth embank- 
ment that is built against the rock-fill is 3 to 1, which is covered with a 
revetment of Ioobc stone 2 to 3 feet thick for wave protection. The rock- 


fill before the addition of the earth facing is illnstrated by Fig. 26, a view 
taken during construction. Fig. 27 ia a view of the finished dam, taken in 
1893. The grade of the main canal leading out from the dam on the east 
side of the valley is 10 feet above the base of the dam, and is excavated 
in limestone to a maximum depth of 38 feet. Fig. 28 ia a vievr of the inaio 
canal and headgates, taken from the lower side. 

Pio. 86.— Lake Avalon Dam. Rock-till ni Pbocbss oy Combtkuctioii. 

The dam was in service nntil Anguet 3, 1893, when it was ruptured by 
a fiood-wave that was in excess of the spillway capacity — the old story con- 
nected with dam failures. The water poured over its crest, and, as this 
style of dam is not calcnluted to withstand Buch an overflow, it speedily 
washed out a breach to the bed-rock over 300 feet in length. This was 
immediately repaired and built 5 feet higher, at a total cost of $86,000. 
The capacity of the open spillway at the west end of the dam was increased 
by widening it from 200 feet to a width of 240 feet, and by catting it 3 feet 
deeper, making it begin to discharge while the water is 15 feet below the 
crest. A second spillway in rock was cut abont half a mile to the west of 
spillway No. 1, having a length of 300 feet. In addition to these discharge- 
channels the main canal below the dam is so arranged that surplus water 
will begin to slop over its banks at a height of 13 feet above the bottom of 
the canal, over a length of about 300 feet. By opening the headgates and 
partially closing the secondary gates across the canal below, this slop-over 
can be given a large capacity of dischai^e. Ordinarily, however, the 


-vrater-level in this section of csoal ia maiDtained to a depth of over 20 feet 
above the floor of the canal by a Beries of thirty-one gates placed on the side 
of the canal, parallel to it, and across the spillway. These gates are hinged 
at the sides, and are each S feet i inch wide by ? feet K inches high. 
They can be opened in an emergeaoy almost instantly by the stroke of a 

hammer upon a latch-releasing bar at each gate, when the pressnre forces 
them to fly open like a door. The opening can be closed above the gates 
by flash-boards, permiLting the closing and latching of the doors. (See 
Fig. 29, taken from Engineering News, Sept. 17, 1896.) The total 
capacity whicli the spillways now have is estimated at 33,000 aecond-feet, 
while the water-level is still below the top of the dam. 

The original cost of the dam was about 990,000, and the recosBtraction 
was therefore bat little less than the first cost. 

Mr. II. II. Cloud, formerly of the Colorado Midland Bailroad, was the 
■chief engineer of the dam, with Mr. E. S. Nettleton acting as consulting 
engineer, and Mr. Lonis D. Blanvelt as principal aBaietant. Mr. Cloud 
EBCribes the cause of the overtopping of the dam to the fact that the spill- 
ways were choked by the debris from bridges, together with the bodies of 
drowned cattle brought down by the river. Another accoant states that 
the gate-keeper and his assistants were in Eddy at the time, indulging in a 
drnnken spree, aud did not start for the dam until the only bridges across 


the river were washed away, and they coald aot cross. When they finally 
secared boats for crossing and reached the dam joat before the disaster, 
thej were nnable to open the waste-gates becanse of a defect in coDBtruc- 
tioQ, since remedied. It was believed that if the lateral waste-gates along 
the canal had been opened when the dood-wave first reached the dam, the 
relief thns afforded would have avoided the disaster. No loss of life was 
reported as a resnlt of the flood, and but little property was damaged. 

The reservoir capacity of Lake Avalon from the floor of the canal to the 
spillway-level is about 6300 acre-feet. 

Irrigation from Reservoir. — The main canal, on the east side of the 

Fig. 38— Canal ElEADaATEa, Lake Avalon Dam. 

river, has a capacity of 1300 second-feet for 3.3 miles, to the janctlon of 
the Southern and East Side canals, the width on bottom heing 15 feet, 
depth 7 feet, and grade 1.5 feet per mile. The Southern Canal from the 
junction down for 9 miles has a capacity of t)80 feet. On this section the 
canal is carried across the river from the east side to the west, in a flume 
468 feet long, 25 feet wide, 6 feet deep, supported on high trestle bents. 
The approaches consist of embankments, or " terre pleius," with maximum 
height of over 30 feet. The second section is 4.3 miles long with 460 
second-feet capacity. The third section is 3 miles with 385 second-feet 
capacity, followed bv 31.6 miles in which the maximum capacity is 315 
second-feet — the bottom width being 14 feet and the depth 4 feet. The 
total length is 40 miles, although operated for bat 31 miles. 


Fio. 80. — SKCTioMfl OF Lake Avalon add Lakk McMillan Bock-f 
Dams, Pecos Valley, N. M. 


The Eaat Side Canal is 19.6 miles long, mth mazimam capacity of 334 
second-feet. The upper 4 miles only are ased, and bnt 16 miles are avail- 
able for service. The entire canal system has cost about $400,000 in all. 
The area irrigated from these canals in 1S9? was as follows: 

Southern Canal 13,000 acres. 

East Side " 2,500 " 

Total 15,500 " 

Tlie area commanded bj these two canals is 110,000 acres, of which 
90,000 acres are under the main Sonthem Canal. 

Water-tightness of Lake Avalon Dam. — The dam is apparently free 
from direct leakage throngh it, although water stands in a pool at the base 

Fio. 81. — Skktch-map ov Pbcos Valley Cakals. 

of the dam, which is believed to come from springs, issuing from the rock. 
From the dam down for several miles there are springs of large volume 
coming out on the river-banks, whose total flow at the stone dam at Eddy, 
as measured by the writer in October, 1897, was approximately 90 second- 
feet. Since the construction of the reservoir these springs are said to be 
increasing in nnmber and volnme. The largest one, flowing 5 to C second, 
feet, broke out in a new place in 1896, some 3 miles below the dam- 
Distinct swirls and miniature maelstroms have been observed on the surface 
of both reservoirs, from which it is surmised that water in considerable 
quantity is thus lost throngh the limestone formation, and that some of the 
springs are fed from this source, although many were in existence prior to 

FiQ. 39. —Map of Pboos Vallbt, N. M., showing Location of Rbsbrtoibb 

AND Canals. 


the bailding of the dams. This '' leakage '* does not in any manner affect 
the stability of the dama and is of interest chiefly becaase of the fact that 
reservoirs in limestone formation are generally to be expected to be subject 
to similar losses, and in this case the illustration is specially well marked 
and visible. 

Lake McMillan Dam. — The Upper Pecos River reservoir is called Lake 
McMillan, and is formed by a rock*fill dam of the same general type as the 
lower one. This was bailt in 1893 under Mr. Loais D. Blaavelt as chief 
engineer. The dam has a top length of 1686 feet, and a maximum height 
of 52 feet The rock-fill portion was made 14 feet wide at top, and the 
earth-fill 6 feet at top — making the total width 20 feet as in the lower 
dam, the slopes being the same, viz., 1^ to 1 on lower and 3.5 to 1 on upper 
side. The inner face of the rock-fill against which the earth rests has a 
batter of 0.5 to 1, the wall being laid up 2 feet thick by hand. The dam 
contains 102,400 cubic yards of rock, 103,600 yards of earth, 3800 yards 
of dry retaining wall, and 6200 yards of riprap. Its cost complete is stated 
to have been $200,000. An auxiliary embankment, 5200 feet long, 10 feet 
wide on top, 18.8 feet maximum height, with slopes of 1.5 to 1 and 3 to 1, 
and containing 78,400 cubic yards, was thrown up to close a gap in the 
ridge near the dam, at a cost of 110,000. It was made entirely of earth, 
paved with stone for a portion of its height on the water-side. When 
visited by the writer in the fall of 1895, and again in 1897, the dam showed 
no signs of leakage, or settlement, or any form of weakness, although the 
reservoir was more than half full. The works have never been completed 
to store more than 50,000 acre-feet, covering an area of 5500 acres, and it 
will be necessary to construct an expensive spillway before a material addi- 
tion can be made to the volume of storage. At present the limit of storage 
is 17 feet below the crest of the dam, above which the water passes oft 
through a gap of such dimensions as to carry 200,000 second-feet before 
the dam could be overtopped. The plan proposed is to close this gap with 
an embankment and excavate a small spillway through solid limestone on 
the right bank, with a capacity of 10,000 second-feet. When this is done 
the water-level will be raised 7 feet, or 10 feet below the crest, and the 
volume of storage will be approximately 89,000 acre-feet, covering 8331 
acres of surface. 

Outlet. — The outlet for the water is provided by means of a canal 1100 
feet long, cut through solid limestone at the east end of the dam, to a 
maximum depth of 35 feet below the crest. This is controlled by massive 
wooden beadgates, placed on the line of the dam, six in number, each 
4 feet wide, and arranged to open to a height of 8 feet by screws. Above 
these openings is a solid wooden bulkhead filling the cross-section of the 
canal. The gates are 6 inches thick, heavily ironed. The water issuing 
from the gates passes back into the channel of the river and thence flows to 


the lower reservoir. The canal is 30 feet wide, aad reqaired the excavatioD 
of 68,000 cabic yards of rock, solid measarement, ail of which was used ia 
making the rock-fill of the dam. The canal beadworks cost $20,000. 

The gates have a discharging capacity of 4400 second-feet when the 
depth of water over the floor of the canal is but 18 feet, and considerably 
in excess of this amonnt when the maximnm depth of 25 feet is reached. 

This type of rock-fill dam appears to possess every element of safety so 
long as sufficient spillway is provided to insare them from being overtopped. 
It seems particularly well adapted to the conditions found in the Pecoa 
Valley, where ledges of limestone crossing the valley appear at the surface 
at intervals, affording reliable foundations for dams, and material for their 
construction; where an abundance of suitable earth is available for backing, 
and where dams of but moderate height are required to impound large 
volumes of water. Here also the country is so open as to make the work 
easily accessible from all sides. These conditions do not prevail in moun- 
tain canyons as a rule, and in such localities, where construction is cramped 
for room, and earth is scarce and hard to obtain, some other material for 
water-tight facing is cheaper and preferable to earth. For the special con- 
ditions existing where they were built these dams must be regarded as the 
best that could have been planned. 

The total cost of the two reservoirs and the canal system depending 
upon them was $776,000, an average of about $7 per acre for the 110,000 
acres of land commanded by the canals. The same company has built an 
expensive cut-stone masonry dam for power purposes at the town of Eddy, 
and another system of canals near the town of Koswell, 90 miles further up 
the valley. The dam is ogee in section, is 320 feet long, 6 feet high, with 
abutments 20 feet in height, and cost $22,000. It was nearly destroyed by 
the flood of 1893, when the Lake Avalon dam gave way, and was subse- 
quently rebuilt. A canal leading from it on the east side, calied the 
Hagerman Canal, covers about 5000 acres, of which 300 acres are irrigated. 
The Northern Canal, near Roswell, N. M., commands 59,000 acres, of 
which 4000 acres were irrigated in 1897. The canal is 38 miles long and 
has a capacity of 300 to 120 second- feet. It is fed directly from springs 
that form the sources of the Hondo Eiver. 

Water-supply, — The area of watershed drained by the Pecos River above 
the southern boundary of New Mexico is approximately 24,400 square 
miles, having a maximum elevation of about 11,892 feet. After leaving 
the main mountain range in Northern New Mexico, where it has its source, 
the Pecos enters upon a tortuous course across the great plateau of eastern 
New Mexico and western Texas, skirting to the eastward of the foothills of 
various mountain groups and isolated peaks, from which the river receives 
numerous important tributaries, but no feeders come to it from the east or 
the region of the *' Staked Plains," whose drainage is caught in shallow 



pools, or sinks into the limestone formation underlying the plains. The 
maximum flow of the river is in the months of May, June, July, and 
AagQst as the result of summer rains, more than 75^ of the entire precipi- 
tation of the year falling in these months. Of the total watershed of the 
Pecos in New Mexico 

{f^ has a mean precipitation exceeding 20 inches. 
505^ " " " from 16 to 20 

20fi " *• " " 10 to 15 

25{^ " " " under 10 


These data are taken from the maps of the U. S. Weather Bureau, palx 
lished in 1891, from which the following data as to mean and maximum 
precipitation at various stations within the Pecos watershed are compiled : 


Mean Annual 



Maximum Annual 



Elevation above 
Sea- level. 

Fort Stanton. N. M 






** Sumner. ** 


Puerto de Luna. *' 


Gnllinas Sorinfirs. ** 


Port Union. ** 


Las Ve&ras. " 


Roswell. ** 


Eddy. •• 


MJ\MX»J f •«•••■••.• 

The estimated discharge of the stream past the southern boundary of 
New Mexico was approximately 700,000 acre-feet in 1890, 1,300,000 acre- 
feet in 1891, and 1,000,000 acre-feet in 1897. In 1893 the discharge 
exceeded « that of 1891. 

The minimum flow above Lake McMillan in August, 1891, was 202 
second-feet, and in August, 1897, 225 second-feet. The maximam of 1893 
was estimated at 42,500 second-feet. The total flow of the stream is thus seen 
to be from 10 to 15 times the combined capacity of the two reservoirs, a fact 
which suggests the probability of a somewhat rapid filling of the reservoirs 
by silt carried in suspension, and also emphasizes the necessity of ample 
spillway capacity. Furthermore it indicates that as the maximum flow is 
dnriog a portion of the irrigation season, the reservoirs do not require to be 
drawn upon except at the lower stages of the river, and hence their duty 
promises to be unusually great. The great surplus of unappropriated water 
is also suggestive of the need for additional reservoirs, some of whose possi- 
bilities are discussed in subsequent pages. 


Duty of Water in Pecos Valley. — From all the evidence obtainable it is 
concluded tliat the average consumption of water in Pecos Valley the first 
year of irrigation is 4 to 5 acre-feet per acre, and the altimate daty after 
the third or fourth year is about 2 acre-feet per acre, including all losses 
by percolation, leakage, and evaporation in the canals. Alfalfa requires 
about three-fourths of a foot at the first watering each year, and yields four 
crops, needing one good irrigation of half a foot in depth at each cutting. 
Sugar-beets, planted in June, have to be irrigated three or four times, 
besides the watering needed for preparing the grouud. They take about 
one-third of a foot at each irrigation. Small grain, sown in October, is 
irrigated once before sowing and once in November or December. In 
March, when dry winds prevail, the surface has to be wetted every ten days. 
In all six or seven irrigations, consuming about 2 acre-feet per acre, 
are required. Orchards need three to six irrigations. The labor-cost of 
irrigation averages about 15 cents for each application, and the cost of 
water is $1.25 per acre for the entire season, regardless of the volume used. 

The Walnut Orove Bock-fill Dam, Arizona. — Among all the rock-fill 
dams that have ever been built or projected in the West unquestionably the 
slenderest and most flimsily constructed was that erected across the 
Hassayampa Eiver, 30 miles south of Prescott, Arizona, in 1887-88, the 
destruction of which by a flood on the night of February 22, 1890, was accom- 
panied by the loss of 129 lives. This disastrous result was predicted when 
it was building by those familiar with its construction, as an event that was 
likely to occur, and the frightful consequences that ensued illustrate and 
emphasize the necessity and importance of governmental supervision of the 
plans and details of construction of all structures of that class, either by 
the State or Federal authorities. It should never have been permitted to 
be built of the dimensions given to it, and the manner of its bailding was a 
conspicuous display of criminal neglect of all requisite precautions to secure 
the safety of any dam, and particularly one of the rock-fill type. 

The dam was 110 feet high, 10 feet thick at top, 138 feet thick at base, 
about 150 feet long at the bed of the stream, and 400 feet long on top. 
These dimensions would not have been excessive for an overfall dam of 
solid masonry laid up in Portland cement, but for a rock-fill the slopes 
were so much steeper than the natural angle of repose of loose rock 
(20 horizontal to 47 vertical on the upper side, and 70 horizontal to 108 
vertical on the lower side) that it was really in danger of settling or sliding 
down to flatter slopes without the assistance of water-pressure against it. 
That it did not do so was solely due to the fact that the faces of the 
embankment were laid up as dry walls, each having a thickness of 14 feet 
at base and 4 feet at top, the center being a loose pile of random stone 
dumped in from a trestle. If these facing-walls had been carefully laid 

ROCK-FILL DA218. 09 

with large stones, on level beds, and an adequate spillway provided to cany 
the waate water aronnd the dam and prevent it passing over the top, and if 
proper foundations had been laid for the entire stmctnre, it might have 
been standing to-day. In a paper read before the Technical Society of the 
Pacific Coast, on October 5, 1888, eighteen months before the dam failed, 
Lather Wagoner, C.E., who was employed on the construction of the dam 
part of the time, called attention to " some very bad work *' on the onter 

Walsdt Gkovb Dam, Arizona. 

wall near the mid-height, and states that he *' advised the company to cat 
a large wasteway and pnt the loose rock below the dam to strengthen this 
weak place." The following is extracted from Mr. Wagoner's paper: " The 
history of the constmction of the dam is one fall of blanders, mainly caused 
by the officers of the company in N^ew York, Work was commeaced on 
company acconnt by Prof. W. P. Blake, who carried a wall across the 


canyoa to bed-rock throngh about 20 feet of Band and gravel. He vas 
sncceeded by Col. £. K. RobineoD as chief engmeer, and the work vae cod- 
traoted for by Nagle & Leonard of San Francisco, Under Col. Robinson 
the dam was commenced in the rear of the Blake wall, and was described 
Id the specifications as being composed of front and back walls 14 feet at 
the base and 4 feet at the top, with loose rock-filling between, the dam to 
be made water-tigb£ by a wooden skin or sheathing. 

"Quarries were opened by the contractors npon both banks of the 
stream above tbe top of dam. * Coyote ' holes from 8 to 15 feet deep were 
charged with low-grade powder (4<£ nitro-glycerine), and the stone dislodged 
in large amounts. The stone was loaded up in cars, having the bed inclined 
at aboat 15°, and these were lowered onto the dam hy a bnll-wbeol and 

Fig. 84. View of Walndt Grove Dam, Abisoka. 

brake, a three-rail railroad being laid on trestle across the dam, at a height 
of from 10 to 15 feet. On the slope midway was a turnout so as to allow 
the loaded cars to pass the empty car. The loaded car was unhooked on 
the level and run out and damped and returned above by the next loaded 
car. The legs of the trestle were left in the wall, only the caps and 
stringers being raised. Dnring the first etagss of construction derricks 
were used to distribute the larger atones; later the center was kept high 
and tbe stones from the wall were moved by bars. The effect of this upon 
the stability of the dam is bad, because it tends to form cnrved beds whose 
slope makes an acute angle with the direction of tbe resultant pressure. 


^^ The company parcbased a sawmill and cut the lumber for tbe dams, 
bnildings, etc., and tbe skin was pat on by contract. Cedar logs, 8 to 10 
incbes in diameter, 6 feet long, were bailt into tbe wall on tbe npper face, 
and projected out one foot. Vertical stringers, 6" X 8'\ of native pine» 
were bolted to tbe logs; tbe stringers were about 4 feet apart. At each 
joint of the stringers a cedar log was built into tbe wall about 2 inches 
above the joint, and two 4'' x 10'' spliced pieces, bolted through tbe log 
and spiked to tbe 6'' X 10'' pieces with galvanized-iron boat-spikes, com- 
pleted the joint. Upon the main wall of tbe dam a double planking of 
3-inch boards was laid horizontally, having a tarred paper put on with 
tacks between the planks. The outer row of planks was calked with 
oakum and painted with a heavy coat of paraffine paint, — refined aspbaltum 
or maltha, dissolved in carbon bisulphide. Tbie junction of the plank-skin 
and the bed-rock was secured by a Portland cement. Through the dam la 
a wooden culvert, 3x4 feet inside, about tbe level of the old creek 
channel; this is boarded with 3-inch plank inside and has a gate to draw 
off the water and waste it. 

*^ The contract for the dam proper was for 46,000 cubic yards, lumped 
at $2.40 per cubic yard. The skin and cementing was extra. Lumber cost 
about $15 per M at tbe dam. 

'' With 70 feet of water abo7e bed-rock the dam leaked 3.75 cubic feet 
per second. Various theories were advanced for tbe cause of the leak; on& 
was that settlement of the dam had forced an opening of t)ie junction of 
the inclined and horizontal skins; and another was that it leaked over tbe 
whole surface. Tbe extreme right-hand skin below the bed of the stream 
is made of but one layer of plank. The machinery for draining tbe water 
was inadequate, and tbe men who did the cementing assured me that they 
worked in 4 feet of water, and that they did not go to the bed-rock. The 
probable cause of leakage, I believe, is due to all three cf the reasons 

The outlet provided for the reservoir was a culvert made partly in 
tunnels through a spur on the left bank, and partly as an arched masonry 
conduit, in which were laid two 20-inch iron pipes with gate-valves at the 
lower end below tbe dam. These pipes terminated above the dam in a 
square wooden tower 90 feet high built of 8" X 8" timbers, 8 feet long^ 
notched one-half at each end, secured by a f-inch rod through each corner, 
the joints calked with oakum, and the outside painted with paraffine 
paint. Two wooden valves were placed to admit water into this tower, one 
at tbe bottom and tbe other 20 feet higher. They were arranged to slide 
on wood, on the outside of tbe tower, with wooden valve-stems, 6 incbes 
square, running up the outside to tbe top, where the operating device con- 
sisted of two pinions, a spur-wheel, and a rack. The openings were each 
about 15 square feet in area, against which tbe pressure with full reservoir 


amounted to a resistance or load of nearly 40,000 lbs. (estimating the 
coefficient of friction of wood on wood at 0.40), while the lifting-device 
gave a mazimam power of less than 1000 lbs. These were pat in regardless 
of the protest of Mr. Wagoner, for the reason assigned that '^ they were 
designed by an engineer and mast work." 

This defect in outlet, however, in no way affected the stability of the 
dam, and even had it been possible to raise the gates at the approach of the 
flood, the relief which they would have afforded could not have averted the 
disaster, as the maximum capacity of the pipe was less than 200 second- 
feet, while the flood must have been several thousand second-feet for 
a considerable period. 

Spillway, — The wasteway as built was 26 feet wide and 7 feet in depth, 
constructed at the right bank adjacent to the dam, the spill falling near 
or against its toe. Its maximum capacity when full was 1700 second- 
feet. As recommended by Mr. Wagoner, the material taken from this 
spillway was placed against the lower side of the dam, as a loose dump, 
increasing its bottom thickness to about 185 feet, and reaching nearly half- 
way up. 

Mr. H. M. Wilson, hydrographer, U. S. Geological Survey, in an able 
review of the construction of this dam published in 1893,* says: 
'^ Mr. Robinson designed a wasteway 55 feet wide and 12 feet deep, cut 
through a ridge one-half mile north of the dam and spilling into a separate 
watercourse, which would in all probability have carried off the great flood 
of 1890. For some unaccountable reason a much smaller wasteway was 
ultimately constructed." 

It is stated that the spillway was being enlarged at the very time of the 
destruction of the dam. Mr. Wilson further says: '^ One of the much-dis- 
cussed points in connection with the construction of this dam was its 
foundation; it was intended that it should be founded on bed-rock. 
Witnesses before the courts, men who had taken part in its construction, 
claimed that the foundation did not reach bed-rock on the up-stream face. 
The body of the loose rock rested on the gravel bed of the river. The 
lower wall rested on bed-rock, but a portion of the upper wall rested only 
on river gravel. This fact was discovered during construction of the dam. 
An excavation was made under the dam and a masonry wall, 14 feet deep 
and about 14 feet wide, was laid, presumably to bed-rock, with another 
portion of this wall turning inward to the east on bed-rock. It was 
claimed, however, that this wall did not come within 5 feet of bed-rock, so 
that in fact, even after the alterations, the dam still rested on the gravel. 
The main up-stream wall of the dam rested for only 2^ feet on this 
secondary base which was built under it, the remainder of the thickness of 

* " American Irrigalion Engiueering," page 298. 


the wall resting on the battress which inclined inward to bed-rock. The 
correctness of this view of the construction of the dam is indicated by the 
fact that considerable water passed ander or throngh the dam in spite of its 
plank sheathi ng. ' ' 

One year prior to the bursting of the dam, Prof. W. P. Blake prepared 
a paper describing it which was published in the Transactions of the 
American Institute of Mining Engineers, New York, in February, 1889, 
from which the following extract is taken : 

'' The reservoir was filled by the first floods and the water rose rapidly 
to and beyond the 80- foot contour-line. As to the effect npon the stream 
below there has been an agreeable surprise either from a partial opening of 
one of the gates or a leak. There has been a constant flow of water from 
the dam, and this has kept a constant stream throngh the yalley, giving 
more water than usual along its course, so that instead of the owners of 
water-privileges denouncing the dam and asking for injunctions, they are 
hoping the dam will always leak to their advantage. These results are of 
great value as to the demonstration of what the functio7is of such dams and 
reservoirs may be throughout the arid regions of the West; even if not 
perfectly tight, they would be of immense value in catching the temporary 
floods and in equalizing the flow of such intermittent streams as the 
Hassayampa and many others." 

It is remarkable that the designer of this dam should have looked upon 
the really enonnous leakage developed in it in a spirit of exultation, as an 
achievement worthy of note, rather than as a source of alarm and danger. 
To write of such leakage as one of the results '^ of great value " requires 
nnusual confldence in the stability of one's work. 

None of the published descriptions of the construction of the dam have 
stated what disposition was made of the culvert under the center of the 
dam at the st|2<»am-bed, after construction was flnished, or whether it was 
walled up or merely closed by a wooden gate. 

The elevation of the dam-site is about 3000 feet above sea-level, while 
the drainage-basin of 311 square miles reaches to maximum altitudes of 
8000 feet. The mean precipitation of the shed is estimated at 16 inches. 
The capacity of the reservoir to the spillway-level, 83 feet above the outlet 
tunnel, was about 10,000 acre-feet. 

The water was intended to be used for placer-mining and irrigation. 
A diverting-dam, located some 20 miles down the canyon, was in process of 
construction at the time of the flnal catastrophe, under the supervision of 
Major Alex. 0. Brodie (late Major of First Begiment U. S. Volunteer 
Cavalry), who barely escaped with his life. 

The original owners of the property have had in contemplation for some 
time past the reconstruction of the dam in a substantial manner, although 
plans for the new structure have not been made public. 


East Canyon Creek Dam, Utah. — A modification of the Otay steel-core 
rock-fill dam wafl completed April 1, 1899, on East Canyon Creek, Utah, 
forming a reservoir of 5700 acre-feet capacity, to be used for irrigation, 
snpplementary to the supply of the Davis and Weber Coanties Canal 

The dam is 68 feet high above the creek-bed, where the width of the 
canyon is bat 50 feet. The length of the dam on top is 100 feet. 

A concrete wall, 15 feet thick, was carried down through the gravel bed 
of the cacyou to bed-rock, a depth of 30 feet, and in the center of this wall 
the steel web-plates were anchored. These are -j^ inch thick for the lower 
20. feet, i inch for the middle 20 feet, and j\ inch for the upper 28 feet. 
The rock-fill is given a slope of ^ to 1, on upper side, and 2 to 1 on lower 
side, the top width being 15 feet. In construction all the rock necessary 
was thrown into the canyon after the concrete base was laid, by a series of 
heavy blasts, and the fill consists of masses that in some cases have a bulk 
of 100 cubic yards. The canyon walls rose to a height of more than 100 
feet above the top of the dam on either side, and the material in falling 
packed very solidly together. After the rock-fill was thus thrown down in 
sufficient quantity an open cut was excavated in it down to the concrete 
wall, having a width of 15 feet at base, and as little slope on sides as possi- 
ble. The steel core was then erected in the cat, and a wall of stone was 
laid up on either side, leaving a space of 4 inches each side of the plate, 
which was filled with asphalt concrete, consisting of 30^ sand, 70^ gravel, 
and sufficient asphalt to fill the voids, requiring 8 lbs. per cubic foot of the 
mass. The inner portion of the rock- fill was laid up as a substantial dry 
wall with headers and stretchers, reaching from the plate out to the water- 
face, the main rocks being placed with a derrick. Notwithstanding the care 
given in this construction the settlement of the wall as the water rose upon 
it to a height of 45 feet was so great as to draw the asphalt concrete away 
from the plate, an extreme distance of 5 feet at the top, bending towards 
the lake, and forming a curve from a point about 30 feet below the top, 
and finally the upper portion of the wall fell off, as indicated by the broken 
line in Fig. 35. The down-stream portion also settled somewhat, causing 
the concrete to part from the steel plates about 6 inches at the top. 

This peculiar action is thought to have been caused by the adhesion of 
the asphalt to the stone wall, the bond being stronger with the stone than 
its adhesion to the steel plates. The rock used is a conglomerate with an 
admixture of red clay, which disintegrated when wet and produced the 
extreme settlement. 

The dam remained with full head of water against it for several months 
without apparent leakage, except through crevices in the bed-rock, and it 
is believed the expense of repairs will be light. The total cost of the 
structure was $40,000. 



The oatlefc to the reservoir is by means of a tannel 200 feet long, the 
bottom of which is 10 feet above the original stream-bed. At the entrance 
to the tannel two 30-inch riveted steel pipes f inch thick are imbedded in 
concrete, controlled by 30-inch Ludlow valves bolted to them, operated 
from a platform projecting from the face of the cliff above. The valve- 
stems are 2^inch steel pipes. The main control of the ontlet is by means 
of two other valves of the same size, placed at the bottom of a shaft, 50 feet 
back from the mouth of the tunnel, between two lengths of cast-iron pipe, 
the whole being imbedded in concrete which completely fills the tunnel. 
These are the working valves, the others being used only in emergency. 

The spillway is at one end of the dam, and consists of a flume 6 feet 
deep, 27 feet wide, discharging below the toe of the dam. The available 
depth of the reservoir between the bottom of the spillway and the floor of 
the tunnel is 52 feet. 

Mr. W. M. Bostaph was the engineer in charge, and Mr. Samuel For tier 
was consulting engineer. 

This account of the construction is an abstract of an article in Ejigineer- 
ing Recordy by M. S. Parker, M. Am. Soc. C. E. The writer is indebted 
to the Record for the loan of the cut illustrating the construction. 

Theoretically the plan of imbedding the steel core in the center of a 
wall of asphalt concrete was an improvement upon that of the Otay dam, 
and had there been no settlement of the rock the construction would have 
been faultless. But in the Otay dam the steel core and the cement concrete 
either side of it are independent of the rock-flU, which is free to settle 
without pulling on the core. This is undoubtedly a superior plan, although 
the ultimate action of settlement when the reservoir is filled remains to be 
tested in the Otay dam, as up to the present writing it has never been filled. 
It has been feared that a rupture of the plates might be produced by the 
strains of unequal settlement. 

Denver Water Company's Bock-fill Dam. — The third American dam 
where steel plates are employed to give water- tightness to a rock-fill is ia 
process of erection on the South Fork of the South Platte River, 48 miles 
above Denver, Colorado, by the Denver Union Water Company. It is the 
highest and most pretentious dam of its class that has ever been projected, 
and when completed it will be one of the highest dams in the world. Its 
estimated cost is $350,000. It is to be 210 feet high, 600 feet long at top, 
and have a base of 450 feet, up and down the canyon. The dam is being 
constructed as a rock-fill, loosely dumped from cars that run by gravity 
from the quarries out upon a bridge that spans the canyon above the top of 
the dam. The lower slope is 1^ to 1, and the upper slope ^ to 1, with a 
dry, hand-laid wall, 15 feet thick at bottom, 5 feet in thickness at top, on 
the water-face. Over the face of this wall on the slope is placed a web or 
skin of sheet-steel plates, 1130 in number, dipped in asphalt, and riveted 


to 6-iQch T beams, placed 5 feet apart, and resting against the wall. The 
plates are flanged at the side of the canyon and bolted to the solid granite, 
with split bolts, driyen 1 foot deep into the rock. The space between the 
plates and the face of the dry wall is filled with concrete, and the entire 
sheet is covered with a layer of concrete from the bottom np to a height of 
126 feet, or 10 feet above the top of the npper outlet or spillway tnnnel. 
The plates are 5' X 10' X f" thick for 75 feet in height; then for the 
second 75 feet the thickness is redaced to -f^ inch, and for the remaining 
60 feet to ^ inch in thickness, the size being uniform throughout. For the 
upper 80 feet the plates will be unprotected from the action of the elements, 
except by such paint as may be applied from time to time. The spillway 
tunnel being located below this level permits the inspection of the exposed 
plates at any time by drawing down the water of the reservoir. The gorge 
is an exceptionally narrow one, and the walls are of remarkably hard 
granite, of close texture, and comparatively free from seams or fissures. 
Indeed the site would be regarded as a particularly favorable one for a 
masonry dam, although its remoteness in the mountain fastnesses would 
render the cost of cement for masonry very high. At the extreme base, 
which is 18 feet below the outlet tunnel, the width between canyon walls is 
but 43 feet. The volume of rock required for the structure is estimated at 
225,000 cubic yards, which is very small indeed for an embankment of such 
unusual height. 

Outlet. — The main reservoir outlet is a tunnel starting 100 feet above 
the dam at the base, and piercing the spur of the mountain, forming one 
of the abutments of the dam. This tunnel is 7 feet wide, and 6 feet high 
for about half its length, to the junction with the inclined spillway tunnel, 
whence its size is increased to 8 feet wide and 9 feet high, the total length 
being 470 feet. 

The spillway tunnel starts 110 feet above the lower tnnnel and dips at 
an incline of 45° to its intersection with the lower tunnel. Its size is 
7x6 feet. Both tunnels are controlled at the upper end by balanced 
valves, set over the tunnel-mouth at an incline of 30*^ from the horizontal. 
These valves are closed by gravity, and opened by hydraulic pressure con- 
veyed to the cylinders at one end of the valves through lead-lined steel 
pipes, laid in trenches surrounded by concrete, from the valves to a reservoir 
located at suitable height on the adjacent mountainside. When submerged 
there will be no other connection with the surface, and no other means of 
moving the valves. The opening of a faucet will put on the pressure that 
will open the valves and release the water from the reservoir, and the entire 
operation will be out of sight and perfectly noiseless. The valve was made 
from drawings prepared by the chief eugineer, Mr. Charles P. Allen, to 
whose courtesy the writer is indebted for the accompanying illustrations. 
Fig. 36 illustrates the construction of the valve, which consists of four 


hoods, or chambers, of cast iron, reetiag oa a heavy framework of T beams 
and opening oat into the tanoel at the bottom. A continnoos shaft passes 
through all the hoods from end to end, apon which are fastened heavy disks 
of cast iron, so spaced as to close all the openings in the hoods when the 
Tftlre is shat, and oncover openiogs at each eod of each hood vhen the 
shaft ia moved. The hydraulic cjlioder, in which power by water nnder 
pressare b applied, is shown at one end of the valve, which end is highest 
as the valve lies inclined over the tnonel-mouth. The valve weighs abont 
flight tons and coat tlSOO at the shops in Denver. 

Additional control of the reservoir oatlet is afforded by two 4ti>inch 
gate-vatves, imbedded in concrete in the tnonel a short distance above the 

point of junction with the spillway tunnel. These lie on their edges, side 
by side, with their stems pointing away from the tunnel and attached to 
hydraulic cylinders, which afford the power for actnating the valves. To 
make room for this mechanism a chamber was excavated in the rock on each 
side of the tunnel, 17.5 feet deep, 12 feet wide, and 7 feet liigh. The 
gates are placed in the line of the upper sides of these chambers, heavily 
anchored to the bed-rock by steel straps and anchor-bolts on all sides, with 
vertical T beams placed against the lower side of the gate-frames, and the 
whole imbedded in concrete, so placed as to form a smooth funnel leading 
to the gates from above, and spreading oat to the size of the tnnnel below. 
Beneath the gates are two 12-inch pipes controlled by gate-valves, to 
serve as a by-pass. The necessity for heavy construction at this point is 
appreciated when it is considered that the pressure upon this bulkhead 
Then the reserroir is fall is nearly 600,000 lbs. The hydraulic cylinders 

Fia. 87,— SoiTiiPi-A' 


and all the moving parts of the valyes are acceBsible from the chambers in 
i?hich they are placed, and from which the water is excladed by concrete 
iralls separating the chamber from the tannel proper. 

The reservoir, when fall, will cover 775 acres and extend np the canyon 
A distance of 7 miles. Its maximum capacity will be 67,210 acre-feet, or 
^1,900,000,000 gallons. A table of contents and areas at different levels 
will be found in the Appendix. 

This site was examined, surveyed, and reported upon favorably in 1897 
"by Col. H. M. Chittenden, Corps of Engineers, U. S. A., under authority 
of the Congressional Biver and Harbor Act of June 3, 1896, directing an 
examination of at least one site each in the States of Wyoming and 
Colorado '^ for the storage and utilization of water, to prevent floods and 
overflows, erosion of river banks and breaks of levees, and to reinforce the 
How of streams during drought and low-water seasons." 

In his able and exhaustive report on this subject Col. Chittenden says: 

'^ This site is remarkable in affording an excellent place for a high 
masonry dam." He recommends a dam 200 feet high, on curved plan, 
with 300 feet radius, whose cubical contents would be 75,200 cubic yards. 
His estimate of cost was 1540,000. The area of watershed above the dam 
is given at 1645.2 square miles, and the volume which could probably be 
fltored annually at 43,620 acre-feet, or a mean of 60 second-feet. The 
average run-off for 1896, a low year, was estimated to be about 166 second- 
feet past the dam-site. The loss by evaporation he estimates at not exceed- 
ing 100,000,000 cubic feet annually. 

The dam was expected to reach the height of 100 feet by May, 1900. 
Pig. 37 shows the false work for the erection of the bridge across the 
canyon, from which the rock is dumped. This bridge rests on trestle 
piers at the ends, which are long enough^ to permit the bridge to be moved 
np and down stream to facilitate the spreading of the rock-flll uniformly 
over its base. The outlines of the reservoir are shown on Fig. 38. 

The English Dam, California. — Among the earlier constructions of the 
rock-flll type was one known as the English dam, situated on the headwaters 
of the Middle Fork of the Yuba Biver, in California, at an elevation of 
6140 feet, which was destroyed June 17, 1883. The reservoir was formed 
by means of three timber crib-dams, and covered an area of 395 acres, 
impounding 650,000,000 feet of water. It was supplied by the run-off from 
a drainage area of 12.1 square miles, reaching to the summit of the Sierra 


]N^evada. The middle dam, the largest of the three and the one which was 
subsequently destroyed, had a vertical height of 100 feet on the interior, 
and 131 feet on the exterior, above the deepest part of the foundation. Its 
thickness at base was 185 feet, length on top 331 feet, and bottom length 
about 50 feet. The original construction consisted of a crib made of tama- 
rack logs, 79 feet high, 100 feet thick at base, with inner slope of 60"^ from 




the horizontal, the crib being filled with rock, and the whole stractare 
faced with plank. It was built in 1856, and repaired in 1876-77, by tear- 
ing out the decayed portion of the old crib and replacing it with new 
timbers. At the same time an addition to the thickness and height was 
made by building a stone facing on the outside, laid up as a dry rabble 
wall, on a slope of 44°. This wall was carried up to a height of 14 feet 
above the top of the original dam, meeting a similar wall laid on the inner 
slope. The upper 7 feet was formed of a substantial timber cribwork. 
The addition to the dam cost $70,000, anxl the entire cost of the three struc- 
tures was 9155,000, or $10.40 per acre-foot of storage capacity. The 
high-water mark, or the spillway-level, was 14 inches below the top of the 
upper cribwork. From the time the repairs were completed until the 
destruction of the dam, about five years, no signs of weakness or leakage 
were manifest, and the water-level was raised annually to the high-water 
mark. On the evening before the break the water-level was 2^^ inches below 
the spillway. The first intimation given of the break was at 5.30 a.m.^ 
when the watchman heard two violent explosions, and on reaching a point 
where he could see the dam he observed the water pouring through a wide 
breach in the upper cribwork. It was inferred that the break had been 
caused by dynamite. In a few moments the water cut an immense gap 
through the structure to its very foundation and the entire contents of the 
reservoir were emptied inside of an hour. The flood-wave caused a rise of 
40 feet at a point 43 miles below. At Marysville, 85 miles below, the rise 
observed was but 2 feet 8 inches, and at Sacramento the extreme rise was 
but 8 inches. The damage done by the flood was estimated at about $4000 
to some wheat-fields that were overflowed. The flood was 24 hoars in 
reaching Sacramento, and the total time in passing that point was 26 hours. 
Had the break occurred in time of flood the opinion is expressed by A. J. 
Bowie, M.E., that it would not have been observed by a marked increase 
in the level of the larger streams of the Sacramento Valley — ^the Feather 
and Sacramento rivers.* While the composite character of this structnre, 
and its age at the time of its failure, would lessen confidence in its stability, 
it is the only one of its type which has given way, and the circumstances 
seem to point to malice rather than inherent weakness as the possible cause 
of its failure. 

The volume of water released by the breaking of the dam was about 
600,000,000 cubic feet, which exceeded by nearly 20^^ the contents of the 
South Fork reservoir whose failure produced the frightful Johnstown, 
Penn., disaster in 1889, and that there was no loss of life resulting from it 
and very slight property damage is quite remarkable. 

* Transactions Technical Society of the Pacific Coast, vol. ii. page 10. — A Paper 
on the Destruction of the English Dam. 


The Bowman Dam. — The timber-crib rock-filled dams of the mining 
regions of California are well illustrated by the Bowman dam, located on 
the Soath Fork of Yuba Biyer, and impounding the drainage from 19 
square miles of the higher Sierras. 

The dam was built in 1872 to the height of 72 feet in a manner similar 
to the original construction of the Eoglish dam, consisting of a timber crib 
of unhewn cedar and tamarack logs, notched and bolted together and filled 
with small stones. The slopes on each side were 1 on 1, and the face was 
made with a skin of pine planking*, laid horizontally. In 1875 the dam was 
raised to the extreme height of 100 feet, by adding an embankment of stone 
to the lower slope, wide enough to carry the entire structure, including the 
crib-dam, to the desired height. The outer face of this embankment was 
made as a hand-laid dry rubble wall in which stone of large size were used. 
This wall is 15 to 18 feet thick at base, and 6 to 8 feet at the top, the stone 
weighing from | ton to 4| tons. Vertical ribs were bolted to the wall on 
the water-face, with f-inch rods, 5 feet long, and to these the plank were 
spiked. These were 9 inches thick, in three layers, for the bottom 25 feet, 
6 inches thick for the next 35 feet in height, and 3 inches thick on the 
upper 36 feet. The outlet to the reservoir is arranged by three 18-inch 
wrought-iron riveted pipes, about 25 feet long each, extending from the 
inner face of the dam to a culvert, built in the dam from the lower side to 
the gates placed at the outlet end of these pipes. The combined discharg- 
ing capacity of the pipes is 280 second-feet, when the reservoir is full. 
They discharge into a covered sluice or flume in the bottom of the culvert, 
21 inches high, 7^ feet wide. The gates are approached by a walk above 
this flume. The culvert is 8 feet high, 7.5 feet wide at bottom, 5^ feet at 
top, made of dry rubble side walls, covered with heavy granite slabs, 
18 inches thick, 6.5 feet long. 

The dam is 425 feet long on top, and has a base thickness of 180 feet. 
Its contents are 55,000 cubic yards, and its cost was $151,521.44. 

Like many of the earlier types of rock-fill dams it was built with an 
obtuse angle in the center, whose apex is pointed up-stream. This angle is 
165°. Its purpose was evidently to give a fancied additional security, and 
was the nearest approach to the arched form which could conveniently be 
given to such a structure. 

The reservoir covers an area of nearly 500 acres, when full, and has a 
maximum capacity of 918,000,000 cubic feet or 21,070 acre-feet. Its cost 
was therefore an average of 17.19 per acre-foot of storage capacity. 

The annual precipitation at the Bowman dam, as recorded for sixteen 
years prior to 1887, ranged from a minimum of 44 inches to a maximum of 
120 inches, the mean being about 72 inches. The watershed is of a 
character to yield maximum run-ofE estimated at 75^ of mean precipitation. 
Maximum floods from melting snows reach 5000 to 7000 cubic feet per 

c/toss Sccrtofif 

Fia. 68b.— Plan and Ckobsskctton or the Fordtce Rocs-Fn.T. Dui, 




second. The minimum annual rainfall is sufficient to gire ample run-off 
to fill the reservoir, while the maximum precipitation would yield sufficient 
to fill it four times in one year. The crest of the spillway is placed but 18 
inches below the crest of the dam. The latter is made as a coping of hewn 
cedar, 18 inches wide on top, anchored by iron bolts into the wall. The 
structure is so well built that a few inches depth of water overflowing the 
crest of the dam would pass off without injury to the lower slope- wall. 
The reservoir is owned by the North Bloomfield Mining Company, and the 
water is used for hydraulic mining. 

The same company have four smaller reservoirs of similar type, con- 
structed at a total cost of 995,000. The following table gives the capacity 
of the principal mining-reservoirs of California, which have been the proto- 
types of rock-fill dam construction in the West, some of which have been 
more fully described in the foregoing pages. Many of them are located at 
the sites of natural lakes whose surfaces have been raised by the erection 
of dams at their outlets. 

Capacity op the Principal Mining-rkskrvoirs op the Hydraulic Mining 

Districts op Northern California. 



Capacity of 


Height of 

Len^cth of 


North Bloomfield 
Mining Co. 




Eureka liake Min- 
ing Co. 




Milton Minine^ Co. 
South Yuba Min- 
ing Co. 



Cubic Feet. 







661.000 000 







58,975 000 



















Shotgun Tiake 

Inland Lake 


Middle Lake 

Round Lake 

Weaver Lake 

Eureka Lake 

Faucherie Lake . .. . 

Jackson Lake 

Smaller lakes  


English dam 

Fordyce dam 

Meadow Lake 

Sterling Lake 








Califurnia • . 


The forces employed in hydraulic mining for tearing down a bank of 
sand, by the use of a large volame of water issaing from a nozzle under 
pressure, gravel, and rock, and transporting the materials considerable dis- 
tances on suitable grades while suspended in water and depositing them 
where desired, have been utilized in the evolution of a novel and interesting 
type of dam-construction, which in many localities can be applied success- 
f ally where the cost by other methods wonld be prohibitive. The condi- 
tions required for the successful employment of hydraulic-dam construction 

1st. The existence of an abundance of water at the proper elevation to 
form a sufi&cient " sluicing-head " ; 

2d. An abundant deposit of materials for forming the dam, convenient 
to either end, and high enough above the top of the proposed structure to 
permit of the requisite grades for carrying the material; and 

3d. A suitable foundation, which is, of course, requisite in all dams. 

The volume of water necessary for a ** sluicing-head " should be from 
5 to 10 cubic feet per second, although smaller heads may be used. Ten 
second-feet may be readily handled in one head, and is more effective pro- 
portionally than smaller heads. The duty of water in hydraulic mining in 
California per miner's inch per 24 hours ranges from 2 to 5 cubic yards 
of solid bank measure loosened and washed down. This is equivalent to a 
duty of from 80 to 200 cubic yards removed in 24 hoars per second-foot of 
water. The ratio of water to solids would thus be from 2.5^ to 6.25^. In 
hydraulic gold-mining it is essential to keep the percentage of solids quite 
low to permit the gold to drop freely to the bottom of the sluice-boxes, 
where it is caught by quicksilver. In dam-construction, on the contrary, 
it is desirable to maintain as high a percentage of solids as the water will 
transport. With sluice grades of 6^ to 10^, the volume which may be 
transported by a sluicing-head of 10 second-feet is 2000 to 4000 cubic yards 
per 24 hours. 

The most suitable material is an admixture of soil, sand, and gravel of 
all sizes. Small angular stones, not exceeding 100 lbs. weight, may be 



carried through the sin ice-boxes with a sufficient amoant of sand and soil 
to enable it to flow well. It is customary to deposit the materials on the 
dam on the lines of the two slopes, which are stadioasly kept higher than 
the center of the embankment. The larger stones are here dropped, while 
the finer materials are carried towards the center where the water is drawn 
o£^ through stand-pipes which lead back into the reservoir or which conduct 
it to a flame or pipe by which it may be wasted below the dam. 

The material for this class of constmction may either be loosened by a 
hydraalic jet of water issuing under pressure and playing against the bank, 
which is the cheaper and more rapid method, or if pressure is not available 
it may be plowed or picked and ground-sluiced. 

San Leandro and Temescal Hydraulic-fill Dams, California. — This pro- 
cess of building up reservoir-embankments has been in vogue in a small way 
in the mines of California from the earliest days of hydraulic mining, but 
the first application of it on a large scale was made by Mr. A. Chabot, in 
the construction of the reservoir-dams for the water-supply of Oakland, 
California, a city of 60,000 inhabitants. 

These dams were planned and built by Mr. A. Chabot, who, though not 
an engineer, had had years of experience as a practical hydraulic miner and 
was the principal owner of the water-works. They are both earthen dams, 
of which the central portion, including the puddle-core, were built up with 
scraper teams and rollers in the ordinary way, but extensive additions to 
their slopes and height were made by hydraulic sluicing. 

The Temescal dam was built in 18(38. It is 105 feet high, 18 feet wide 
on top, with original slopes of 2^ to 1, which have been greatly increased 
by the material sluiced in from year to year subsequently. The water 
available being limited in supply to a few days each season after storms, the 
work was continued for a number of seasons as an economical method of 
increasing the bulk of the dam. It forms a reservoir of 18.5 acres, with a 
capacity of 188,000,000 gallons. 

The San Leandro dam was built in 1874-75, and has a height of 120 
feet above the stream-bed. It is located 9.5 miles east from Oakland, 1.5 
miles above the village of San Leandro, at an elevation at base of 115 feet 
above tide. The total volume of the dam is 542,700 cubic yards, of which 
about 160,000 yards were deposited by the hydraulic process. The water 
was brought 4 miles in a ditch, and the sluiced materials were conveyed in 
a flume, lined with sheet-iron plates and laid on a grade of 4^ to 6^. The 
water used was 10 to 15 second-feet, and the ground-sluicing method was 
alone employed, as it was not convenient to get water under pressure. The 
cost was estimated at one-fourth to one-fifth that of putting the earth in 
place with carts or scrapers. The entire cost of the dam proper was about 
$525,000, but the outlets, wasteway-tunnels, and improvements of various 
kinds about the reservoir have increased the total to over $900,000, or about 



$68 per acre-foot of storage capacity. The reservoir covers an area of 335 
acres and has a mazimnm capacity of 13,370 acre-feet, or 4,32li,446,000 
gallons. The area of the watershed tributary to the San Leandro dam is 
50 square miles, from which the run-off is ordinarily in excess of the storage 
capacity, and considerable difBcuIty was experienced in disposing of the 
snrplns, without washing away the dam, nntil a waste-tnnnel, 1100 feet 
long, with a capacity of 2000 aecond-feet, was constracted in 18S8, discharg- 
ing into the stream half a mile below the dam. 

The plans and sections of these dams are shown in Fig. 39, in which are 

Temeecal, Elevation. 

Fio. 89.— Plarb aro CBoes-BBCTiona op Bah Leandro and Tehescal Daks. 

represented the restraining levees for holding the ainiced material in 
terraces, as it was deposited on the outer slopes. The deposit on the inside 
was made by simply dumping the contents of the flnme into the water and 
allowing it to assume its own slope on the surface of the embankment. 

Hydraulio-fill Dam at Tyler, Texas. — In projecting improvements to the 
water-works of Tyler, Smith County, Texas, in May, 1894, the engineer of 
the company, J. M. Howells, C.E., conceived the idea of creating an 
impounding- reservoir by means of a dam to be constracted by the hydranlic- 
jet and sluicing method. The only means of getting water to the works 
was to pump it, and all the materials used in the dam were sluiced in from 
a neighboring hill. The total cost of the work, including the plant and all 
the appurtenances of the reservoir in the way of gates, outlet-pipes, etc., 
vas but 4| cents per cubic yard. The dam, Fig. 40, is hlh feet long on 














top, 32 feet high, and contains 24,000 cubic yards, the inner slopes being 
3 on 1, and the outer 2 on 1, with a 4-foot berm on the inside 10 feet below 
the top. The maximum depth of water is 26 feet; the reservoir covers 177 
acres and impouuds 576,800,000 gallons, or 1770 acre-feet. The water 
used in sluicing was forced through a 6-inch pipe by a Worthington steam- 
pump of 750,000 gallons daily capacity, belonging to the old city pumping- 
station situated on the opposite side of the valley from the hill which 
supplied the material. This hill is 150 feet high, and the pipe terminated 
about half-way up from its base, where a common fire-hydrant was placed 
to which was attached an ordinary 2^-inch fire-hose, with a nozzle of 1^ 
inches diameter. From this nozzle the stream was directed against the face 
of the hill under a pressure limited to 100 lbs. per sqaare inch (Fig. 41). 
The washing was carried rapidly into the hill on a 3^ up-grade which soon 
gave a working face of 10 feet or more, increasing gradually to 36 feet 
vertical height. By maintaining the jet at the foot of the cliff the latter 
was undermined as rapidly as the earth could be broken up and carried 
away bv the water. The material found in the hill consisted of a soft, 
friable sandstone infiltrated with ocher of varying shades of yellow, brown, 
and red, alternating with clay and sand, the whole overlaid by a surface 
soil of sandy loam, 2 to 6 feet deep. Experiment and observation led to 
the conclusion that 65^ of the entire mass washed into the dam was sand, 
and 35^ was clay. 

In beginning the work a trench 4 feet wide was excavated throngh the 
surface soil down into clay subsoil, a depth of several feet, and this trench 
was refilled with selected puddle-clay sluiced in by the stream. Then the 
form of the dam was outlined by throwing up low sand ridges at the slope- 
lines, which were maintained as the dam rose in height, in the form of 
levees by men with hoes (Fig. 42). A shallow stream of water was thus 
maintained over the top of the embankment, the water being drawn off 
from time to time, either into the reservoir or outside, as preferred. As 
the embankment rose it assumed a grade-line from the side nearest to the 
source of supply to the opposite side. The material was transported from 
the bank in a 13-inch sheet-iron pipe, put together with loose joints, stove- 
pipe fashion. This pipe extended from near the face of the bluff, where 
the jet was operating, across the center line of the dam, and was so arranged 
as to be easily uncoupled at any point, so as to direct the deposit where 
required to build up the embankment uniformly. When the end of the 
dam nearest the bank reached the full height the pipe was raised on a 
trestle to give it grade for transporting the sand to the opposite side. A 
spillway was cut out by the same sluicing process, at the end of the dam 
farthest from the side where the main sluicing operation was conducted, 
and the earth from it was also placed in the dam. It was found that the 
quantity of solids brought down by the water varied from 18ji in clay to 


30^ in sand. Sharp sand does not flow as readily as rounded sand or 
gravel, and is improved in delivery by aa admixtare of clay and stones. In 
this case the clay acted as a lubricant, which served to increase the carrying 
capacity of the water. 

The entire volume of water pumped in building the dam, if computed 
by the percentages of solids given, must have been less than 20,000,000 
gallons, although it is unlikely that these percentages were maintained 
throughout. The volume discharged through the nozzle under the stated 
pressure must have been about 1.4 second-feet, which is a very small 
sluicing-head. The nozzle velocity was 115 feet per second. The limita- 
tion of the nozzle pressure to 100 lbs. per square inch restricted the 
delivery of water and its effective power in disintegrating and transporting 
the soil to considerably less than might have been accomplished with higher 

The entire cost of the dam with all its accessories is said to have been 
bat 91140, which must be regarded as a marvel of cheapness for a structure 
of the size of this one and performing the function of an impounding dam 
of its magnitude. Another interesting feature connected with it was that 
the construction of the reservoir permitted the new pumping-station 
supplying the city of Tyler to be located on the border of the pond so much 
nearer to the town than the location of the original pumping-plant, which 
was at the site of the dam, as actually to save the cost of the dam in the 
length of main pipe that was thereby dispensed with. 

The average cost per acre-foot of storage capacity in the reservoir formed 
by the dam was but 90.65. The dam is reported to have no apparent 
defects and gives satisfactory service. Mr. L. W. Wells was engineer and 
foreman in charge of the works, from whose memoranda, furnished by 
courtesy of Mr. Howells, consulting engineer, the foregoing description has 
been compiled. The accompanying illustrations were obtained through the 
courtesy of Mr. Ben R. Cain, of the Tyler Water Company. 

La Mesa Dam, California. — In the spring of 1895 the San Diego Flume 
Company, which supplies the city of San Diego, California, with domestic 
water and furnishes an extensive territory of agricultural land with an 
irrigation-supply through a long line of flume, built an impounding- 
reservoir on the Mesa, or tableland, 8 miles northeast of San Diego, near 
the terminus of the flume, for the parpose of impounding the tail-water 
of the flume and the surplus accumulating at night, as well as to store the 
flood-water of the San Diego River in winter to the extent of the unused 
capacity of the flume. The dam (see Figs. 43 and 45) was designed and 
constructed by J. M. Howells, C.E., who was then president of the 
Flume Company. 

With the successful experience obtained with hydranlic dam-construc- 
tion at Tyler, Texas, the previous year, Mr. Howells applied the same 




Is J 



3 5-' 



methods Iq a modified form to the erection of La Mesa dam. The sicnation 
and materials available were less fayorable than at Tyler, and it was not 
possible to obtain water ander pressure for disintegrating the soil. Hence 
it was necessary to resort to groand-slaicing alone. 

The dam-site is in a narrow gorge cut through hard porphyry, whose 
walls are but 40 feet apart at the stream-bed, and stand nearly vertical on 
one side for 40 feet in height, from which elevation the ground slopes 
gently upward on both sides. The site had been regarded as particularly 
suitable for a masonry or rock-fill dam, as the foundations were of the best 
character and the materials at hand all that could be desired. With these 
advantages in view the first plans made were for a rock-fill with plank 
facing, of the following dimensions: height, 55 feet; length on top, 470 feet; 
thickness at base, 110 feet; at top, 12 feet; upper slope, i to 1; lower slope, 
1 to 1; volume, 15,000 cubic yards. Bids were received on these plans, 
the lowest of which called for 99 cents per cubic yard for the rock-fill, and 
$2.08 for dry rubble wall. These prices are but 55^ to 66^ of the contract 
prices paid for the Escondido dam. The total cost under these bids would 
have been 120,260, exclusive of the plank facing and the outlet-gates and 
pipes. The hydraulic-fill dam proposed by Mr. Howells was given the 
preference by the company on a guarantee of a material reduction of cost 
below the bids for the rock-fill dam, and, although numerous difBcnlties 
were encountered, it was finally completed for about 117,000, including 
plant, excavations for foundations and spillway, outlet-gates, culvert and 
stand-pipes, paving of slopes, and all accessories, and furthermore it was 
built to a height of 66 feet, or 11 feet higher than the proposed rock-fill. 
It was made 20 feet wide on top, with a base width of 251.5 feet. All of 
the dam except a few feet on top, which had to be finished out with 
wagons, was put in place by flowing water. The surplus water from the 
flume was used at a time when little or no irrigation was going on, and at 
the same time the water was stored in the reservoir as it was being formed 
back of the dam. 

The total volume of material handled was 38,000 cubic yards, some of 
which was transported an extreme distance of 2200 feet, and taken from 
an area of 11.5 acres, which was stripped to a mean depth of 2 feet. Had 
the material been as abundant and as accessible throughout the construc- 
tion as it was up to the time one-fourth of the dam was in place, the entire 
structure could have been finished for 25^ to 30^ of its ultimate cost, but 
unfortunately it was found that below a depth of 2 feet from the surface 
the gravel and cobblestones of the mesa were cemented together so hard as 
to resist further washing, and this condition necessitated the employment 
of horses and scrapers to bring much of the material used to the sluiceways, 
at greatly increased cost. The results, considering all the unfavorable con- 
ditions, are an indication of what can be accomplished by this process where 


sarroaadiQg conditions are more anspicioas. The surface soil and sand 
contained in the coarse gravel constitnted less than one-third of the mass, 
and consequently the dam can properly be termed a rock-fill with an earth 
core. The deposit on the dam being always near the oater slopes, the 
larger stones were natarally dropped there, while the finer materials shaded 
cfl towards the center. The gravel is of all grades, from egg size to large 
cobbles, 8 to 10 inches in diameter. On the enter slopes the largest of 
these were laid up in a dry wall of uniform slope and surface. 

In beginning the work a trench was excavated in bed-rock, as shown in 
Fig. 44, from 2 to 5 feet deep, 20 feet wide at center and tapering to 5 feet 
at the ends. At right angles to this trench in the bed of the gulch a 
culvert was built to reach entirely through the dam at its widest point. 
This culvert, whose details are shown in Fig. 45, consisted of a coucrete 
conduit, 48 inches wide, 30 inches high, extending from the inner face of 
the dam outward 180 feet, to a point 72 feet from the lower toe, where it 
connects with two 24-iQch cast-iron pipes, that form the outlet to the 
reservoir. One of these pipes connects with a wood-stave pipe supplying 
water to San Diego, and the other is used as a waste, or clean-out, pipe. 
Both are controlled by gate-valves at the toe of the dam. The walls of the 
concrete culvert are 12 inches in thickness, and four vertical stand-pipes 
connect with the culvert at intervals of 35 feet from the inside end. These 
stand-pipes consist of 24-inch vitrified pipes, surrounded with concrete, 
which pass upward through the body of the dam, and are now used as 
outlet-pipes to the reservoir at four different levels. During construction 
they performed the important function of conveying the water into the 
reservoir after it had dropped its load of gravel and sediment on to the 
surrounding embankment They were built up a joint at a time in 2-foot 
sections, as the work progressed, and were finished off at the top with brass 
ring and fiap-valve, the latter being controlled by rods reaching up the 
slope through the water to the surface. (See Fig. 43.) These flap- valves can 
only be opened when pressure is relieved by closing the gate-valves below. 

The volume of water used in constructing the dam was from 300 to 400 
miner's inches — 6 to 8 second-feet, which was all that could be spared from 
the flume after supplying the domestic consumption in San Diego and along 
the line, and the little irrigation which is kept up, even in winter, when 
the rains do not come just right. From the end of the 37-mile flume, 
which terminates on the mesa 10 miles from San Diego, the water was 
siphoned across a deep ravine by a 36-inch wood-stave pipe, 3000 feet long, 
discharging into a ditch which carried the water 1.5 miles to the top of the 
ridge overlooking the dam-site on the south. From this main ditch at 
various points laterals were carried down the slope of the hill towards the 
dam on a grade of 6^, dividing the ground into irregular zones of 50 to 100 
feet in width, by several hundred feet in length. In sluicing these divisions 


were stripped off clean to the cemented gravel bed-rock, beginning next to 
the head ditch and working downward toward the dam across the end of 
the strip. The fall from the apper-line ditch to the lower side of the zone 
was as great as the slope of the gronnd would admit, — the greater the fall 
the more rapidly the sluicing was done. The work accomplished was satis- 
factory as long as this slope was not flatter than about 25^, but as the hill 
from which the material was taken rounded off toward the top the Telocity 
of the water in the cross-ditches became lessened, until it was insufficient 
to erode the material from its bed, and the process had to be assisted by the 
nse of picks or plows, where the ground was not too soft for teams to get 
oyer it. This additional labor of loosening materially increased the coat. 
All of the material was obtained from one side of the dam, which was a 
farther disadvantage. 

As the stream secured its load of earth or gravel it was conveyed along 
the line of the lower ditch by 24-inch wood-stave pipes until deposited on 
the embankment. About 2000 feet of this piping was used in the work, 
the first cost of which was 90 cents per foot, exclusive of the lining of 
strips of tire-steel subsequently added to resist wear and tear. It was made 
in sections of 10 to 14 feet, loosely placed together and connected by stripa 
of canvas wound around the ends of abutting joints and held in place by 
an ingenious tourniquet of tarred rope placed back of the last round band 
on the end of each section, the twist on one being made by a long nail, and 
on the other by an 8-inch piece of ^-inch gas-pipe, the nail slipping into 
the gas-pipe and so preventing both ropes from loosening or untwisting. 
During a portion of this work the pipes were supported to the desired 
grade-line ou the dam by trestle-work. A wire cable was also used for thia 
purpose, aUhough the latter did not give satisfactory results. Fig. 46 illus- 
trates both methods of suspending the pipes, and shows the clam when about 
30 feet high. The necessity of frequently unjointing the pipe on the dam 
for distributing the material evenly over the line from side to side made 
the use of a canvas joint over that portion of the pipe inconvenient, and it 
was replaced by loose straps of iron bolted to the pipes on the sides, 
which kept them in line, and the water would shoot across the joint with- 
out material loss. These joints were easily taken apart when desired. 
The pipes were found to wear very rapidly, and were lined, first with stripa 
of wood, and later with strap-iron or tire-steel. Cast-iron pipe or open 
flumes would be preferable for this sort of service. 

The work on the dam began February 14, 1895, and daring the first thirty 
working-days, of 24 hours each, 21,000 cubic yards, or bb% of the entire 
dam, were put in place — an average of 700 cubic yards per day, although at 
times more than double this amount was moved in 24 hours. The ratio of 
solid embankment to water used during this period was abont 3.3^. The 
force of men employed varied from 27 to 45, working in eight-hour shifts* 



Two men were kept on the damp directing the stream of material and 
building up the outer edges of the slopes to the proper lines, while the 
others were chiefly engaged in ground-sluicing. With looser or deeper soil, 
bt under conditions permitting the use of a jet of water under pressure, the 
cost of loosening, which in this case was the chief item of expense, would 
be reduced to a nominal amount. 

It is apparent that an embankment built in this manner is compacted 
as thoroughly as it could be by any process of rolling and is not subject to 
furbher settlement. It is also manifest that the finer materials are by this 
process precipitated in the interior of the fill, next to the discharge-outlets 
for the water, and that the particles are in a general way graded in size 
from the outside toward the center. In this dam all of the stand-pipes are 
placed inside of the center line, as shown by the section of the dam 
(Fig. 47)^ and therefore more of the coarse and permeable bowlders and 
gravel are placed on the outer half of the embankment, where they afford 

Fig. 47.— Cross-section of La Mesa Dam. 

ready drainage to the percolation that might find its way through the dam. 
(See Fig. 47.) Thus the failure of the structure through the ordinary 
process of supersaturation and the sloughing of the outer slopes is rendered 
highly improbable if not impossible. A dam built in this way is tested as 
it grows by the pond of water standing on top of it and the rising lake 
behind it, and if any weakness exists it is sure to be discovered and remedied 
by the operation of natural laws. 

This dam is not entirely free from leakage, although as the water comes 
through quite clear it causes no anxiety and shows no tendency to increase. 
The leakage measures 100 gallons per minute when the water in the reser- 
voir stands at the 54-foot level, and 23 gallons per minute when the water 
stands at 4G feet. 

The reservoir-basin is large enough to impound 18,890 acre-feet if the 


dam be raised to the 140-foot contoor. Such a dam, of safe dimeusioos, 
would contain 683,000 cubic yards, and its constraction has been seiiousi; 
coDsidered, the material to be obtained bj excavating the interior of the 
basin, conrejing it to the dam by the hydraulic method and then hoisting 
it in place by mechanical means. 

The elevation of the base of the dam is 433.5 feet above sea-lcTel, and a 
24-ioch wood-stave pipe, C500 feet long, banded to withstand 180 feet 
maximum pressure, connects it with a 15-inch steel main that is laid from 
the end of ihe main flume to San Diego. The location and elevation of the 
connection of these pipes has practically determined the 43-foot contour in 

Pio. 48.— La Mesa Htdkadi 

the reservoir as the lowest level to which the water will ordinarily be drawn 
when used for city service, unless a more direct connection be made. Id 
times of scarcity the water below the 43-foot level has been pumped from 
the reservoir. 

Lake Christine Hydranlic-flll Dam, California. — Some years ago the Saa 
Joaquin Electric Company erected a power-plant on the San Joaquin River, 
34 miles north of Fresno, to utilize water brought from the North Fork of 
the San Joaquin to the power station. The power-drop at this place la 
1410 feet, and the plant is remarkable as one of the first to make nse of bo 
high a drop, as well as for the long distance of the transmission of power, 
as the company deliver electricity to Hunford, a distance of 70 miles, as well 


as to Ereano. The plant was designed and built by J. J. Seymoar, C.E., 
president of the company, and by J. S. Eastward, chief engineer, under 
contracts with the General Electric Company. The plant was entirely suc- 
cessful until the recent drouth developed such an unprecedented shortage 
in the low-water supply as to diminish the possible power output below the 
demands upon it. To remedy this deficiency the company is engaged in 
the erection of a storage-dam for impounding the flood run-off of the Korth 
Fork. The dam has been planned and is being built by J. M. Howells, 
C.E., and is to be purely of the hydraulic-fill type. The general dimen- 
sions are as follows : 

Maximum height 100 feet. 

Length on top 720 " 

Slope on water-side 2:1. 

tower Bicie • ■«••••«•«•..•.•.. XtO r i. 

Width of canyon at base 30 feet 

Width 65 feet higher 300 feet. 

Water for sluicing is bronght to the dam-site a distance of 5 miles, by 
flumes and ditches. The volume used is 15 second-feet (750 miner's 
inches), which is delivered to the summit of a hill overlooking the dam and 
200 feet above it. This hill, which is to farDish the materials for bnilding 
the dam, has been surveyed and explored by borings to determine the 
quantity and quality of available earfch for the purpose. The hill has an 
underlying base of granite, which has disintegrated very irregularly, leaving 
hard exposures at various points, while in places the depth to solid rock is 
very great. This disintegrated material is sandy in places, and in spots it 
has passed into the clayey stage, while fragments of granite still lie bedded 
intact, furnishing rock for the outer paving of the embankment. Hard 
bed-rock is exposed over nearly the entire area covered by the dam. It is 
of granite throughout, hardest near the level of the stream, where erosion 
has polished it smooth and glassy. Higher on the sides it is not so hard, 
but will make an excellent foundation. Advantage has been taken of a 
cut, blasted out from the solid rock, at a level 14 feet above the stream-bed, 
by an old mining company for a ditch grade, in which to place the outlet, 
sluices. This cut is arched over with masonry for the entire width of the 
dam, and will ^erve to carry the flow of the stream during construction. 
Oates are set in this cut on the center line of the dam, to be closed when 
the dam is finished and storage begins. The gate-stems will extend up 
through a circular shaft, 22 inches in diameter, 3 inches thick, reaching to 
the top of the dam. This shaft isnnade of successive rings of cemeat pipo, 
12 inches in height, which are added one at a time, as the dam. rises. 
During construction this shaft will serve to draw off the surplus water from 


the pond formed on top of the embaakment, after its load of material has 
been dropped on fche rising dam. 

A center core of doable plank sheeting will be carried np through the 
dam from bottom to within 10 feet of the top, and throaghoat its entire 
length. This sheeting will be embedded in concrete at bed-rock. The 
concrete will be made of high grade, thoroughly rammed and water-tight 
on the upper side of the sheeting, but made open and porous on the lower 
side, with a 4-inch pipe molded in it close to bed-rock and running the 
entire length of the sheeting. This conduit is intended to drain the dam 
of any water which may pass through seams in the rock, underneath the 
dam, or leakage through the puddle-core in the center. The outlet to this 
drain is a 6-inch pipe of cement, laid from the lowest point in the drain to 
the outer toe of the dam. 

The dam will be composed of a combination of rock, gravel, coarse and 
fine sand, and clay, the finer particles being graded by the varying velocities 
of the water and deposited in the center of the embankment, while the 
coarser materials, and fragments of granite, up to 12 inches in dimension, 
will be dropped on the outer faces and slopes. This method of filling will 
more perfectly fill all the voids in the dam than any other possible means. 
The materials will be transported from 600 to 2000 feet, and deposited on 
the dam by the agency of water alone. The fineness of the central mass, 
and its impervious character, are relied upon to remain constantly moist and 
free from air, and thus preserve the wooden sheeting from decay. To more 
thoroughly mix the materials of the puddle-core and break up a tendency 
to stratification, it is proposed to draw wagon-wheels, properly weighted, 
backward and forward, parallel with the central sheeting, during construc- 
tion, by means of a wire cable and capstans. 

The dam is estimated to cost but $25,000, including the entire cost of 
the fiumes and conduits. Considering the remoteness of the site in the 
mountains, and the difficulty involved in transporting supplies, this cost, 
for so high a dam, .is remarkably low, and the completion and test of the 
work will be looked forward to with unusual interest. The spillway of the 
dam will be through a natural gap, located 800 feet away from the dam. 
This spillway will be 100 feet wide at the 90-foot level, and 225 feet at the 
100-foot level. 

The reservoir will have a length of 3 miles, and an average width of ' 
about i mile. Its capacity will be approximately 360,000,000 cubic feet 
(8264 acre-feet), which is estimated to yield a fiow daring low-water period 
of three times the present requirements of the power-plant. 

Hydranlic Fills on the Canadian Pacific Bailway. — Further examples of 
the successful employment of hydraulic- mining principles to the work of 
building embankments are to be found on the Pacific coast, but none more 
instructive than the extensive hydraulic fills made by the Canadian Pacific 


Bailway in British Oolambia, where trestles of great height are being sup- 
planted by earbh and gravel embankments made by the agency of water 
alone. The methods employed differ materially from those described in the 
foregoing pages, bat will doubtless find freqnont application elsewhere in 
irrigation-dam consfcraction. 

At trestle No. 374, near North Bend, in Fraser River Canyon, 110 miles 
east of Vancouver, there was required to fill a chasm an embankment 231 
feet in height, containing 148,000 cubic yards. When visited by the writer 
in November, 1896, the fill had reached a height of 167 feet and contained 
70,000 cubic yards, all of which had been put in place by the hydraulic 
process. The plant used consisted of 1450 feet of double-riveted sheet-steel 
pipe, 15 inches in diameter, 1200 feet of sluice-boxes or flumes, about 3 feet 
wide and the same depth, one No. 3 double-jointed *' Giant " monitor with 
5-inch nozzle, and a large derrick fitted with a Pelton wheel connected with 
the winding-drum of the derrick and operated by diverting the jet of water, 
nsed in piping the bank, npon the wheel when loads were to be hoisted by 
the derrick. The gravel bank where the material was obtained was 1130 
feet distant from the center of the track, and from this pit the pipe was 
laid to an adjacent stream, 1450 feet, in which length the fall available was 
125 feet. The sluice-boxes were laid on a grade of 11^ for the first 425 
feet, increasing to 25^ the rest of the way. They were chiefly supported 
on trestles. These boxes, constituting a continuous flume, were paved with 
wood blocks on the lighter part of the grade, and with pieces of old railway 
rails, laid close together lengthwise of the flume, where the grade was 

One of the most serious difiSculties here encountered — and each locality 
develops its special problems — was the fact that about 50^ of the materials 
in the gravel-pit was such as to be classed as cemented gravel; 20^ con- 
sisted of bowlders, too large to pass through the flume and requiring to be 
hoisted out of the way and piled up by the derrick; while but 30^ was 
loose gravel, of the character Best adapted for the work. Notwithstanding 
these disadvantages the result? accomplished are quite remarkable, as the 
entire cost of the work, including the plant, was but $5089, an average of 
7.24 cents per cubic yard. The entire force employed consisted of eight 
men, disposed as follows: 1 piper at the monitor, 1 man at the head of the 
sluice-boxes and in the pit, 2 on the flume, ^' driving" the material along 
to prevent choking, 3 on the dump, distributing the material and making 
brush mattresses for the slopes, and 1 foreman, a carpenter, chiefly engaged 
on general repairs of flume and overseeing the work. The time occupied 
was as follows: sluicing, 95.3 days; removing bowlders from the pit, 50.4 
days; repairing flume and plant, 13.5 days; total, 159.2 days of 10 hours 
of the entire force. The total number of yards moved, divided by the actual 
working-time when sluicing was in progress, gave an average of 738 cubic 


yards per day of 10 hoars, or at the rate of 1771 cabic yards per 24 honrs. 
The water used was approximately 11 cubic feet per second, or 550 miner's 
inches under 4-inch pressare (440 inches under 6-inch pressure), the duty 
performed being 3.22 yards per 24-hoar inch under 4-inch pressure, or 
4.02 cubic yards per inch under 6-inch pressure, which latter is the unit of 
measure most commonly used in the hydraulic mines. 

Had the gravel-bank been free from large bowlders, the work could have 
been done in two-thirds of the time actually occupied, and had the pressure 
been greater and the gravel all loose instead of being partially cemented, 
requiring the use of explosives to loosen it, the duty of the water, on the 
high grades available for the flume, should have been increased more than 
threefold, as the ratio of solids carried was only about 5^ of the volume of 
water used. An understanding of all these conditions suggests what might 
be accomplished by this method with a perfect combination of circum- 
stances, viz. , water under pressure of 400 to 500 feet head, loose materials 
in abundance for washing, freedom from rocks of large size, and heavy 
grades to the dump. 

In building the embankment no provision was made for draining off the 
water down through the center, but it was allowed to pour over the slopes, 
which were protected from erosion by brush and tree-tops woven in alter- 
nating layers along the edges of the fill. Old track-ties and poles were also 
used with the brash. In addition to this protection it was necessary to 
exercise care to prevent the water from concentrating in channels or from 
reaching to the sides or flowing down the hill over the natural surface. By 
keeping the sides of the fill as nearly level as possible the water was spread 
in a thin sheet over the face-slopes and reached the bottom of the embank- 
ment without washing or doing injury. The slopes are remarkably trae 
and uniform, and the embankment was packed very hard, particularly near 
the end of the fflaice, where the gravel had dropped from a considerable 
height to the dump below. 

The device employed for handling the .bowlders in the pit by water- 
power was ingenious and effective, and was similar to those in common use 
in hydraulic mines, where water under pressure is turned at will upon a 
tangential water-wheel with peripheral buckets. This wheel, being attached 
to a winding-dram, the wire hoisting-rope leading from the derrick boom 
is rapidly wound up and the load handled at will. A friction-brake with 
long lever gave the operator perfect control of the load and enabled him to 
lower it as swiftly or as gently as desired. Sharp turns in the flume were 
made by vertical drops of 2 feet at the angle, and two turns of 90^ each 
were thus successfully made. 

Bowlders with one or two square feet of face would sometimes stop 
rolling, and if not quickly started would cause a jam and overflow, 
endangering the flume on the gravel hillside. Hence it was necessary to 


employ two '' driyers" to patrol the portion of the flnme where the grade 
was lightest, to keep all such stones in continaoas motion. On the heavier 
grade, however, no such attention was necessary. 

In the sammer of 1894 the railway company made a similar fill of 66,000 
cnbic yards, at the crossing of a stream called Chapman Greek, the average 
cost of which was 7.5 cents per cubic yard, of which 3.2 cents was for 
plant. The actaal work of sluicing was bat 1.78 cents per cubic yard. 
In this case also, it was necessary to use explosives to loosen the gravel and 
prepare it for washing. 

In 1897-98 the same company made a similar fill at the crossing of 

Mountain Greek, in the Selkirk Mountains, requiring 400,000 cubic yards. 

(See Fig. 50.) The total length was 10,086 feet over all, with extreme 

depth of 154 feet. The fill was carried up on a slope of 1^ to 1. Between 

Aug. 10 and Not. 1, 1897, over 65,000 cubic yards were sluiced in place, at 

the following cost: 

Mattresses $1370.79 

Sluicing labor 1195.96 

Maintenance and repairs 678.90 

Superintendence and tools 385.05 

Total $3630.70 

This gives the average cost of the first 65,000 cubic yards at 5.59 cents 
per yard. Including a proportion of the plant, the average was less than 
8 cents per cubic yard of embankment. The work was done in about 60 
working days of 10 hours each, and the average was nearly 1100 cubic yards 
per day. The water was delivered to the nozzle of the monitor under a 
head of 160 feet, the diameter of nozzle being 5.5 inches. The volume 
was therefore 15.75 second-feet, or 787 miner's inches. The ratio of water 
to gravel was as 19 to 1 and the duty of the water was nearly 4.2 cubic 
yards per 24-hour inch under 6-inch pressure. The sluice-boxes had a 
grade of 8^. The water-supply was brought in a flume, 4 feet wide, 2 feet 
high, 2 miles long, built on a grade of 20 feet per mile. The entire plant, 
including roads, camp, stables, flume, pipe-line 1200 feet long, sluice-boxes 
600 feet in length, etc., cost $10,038.40. Considerable expense was caused 
by snow and land-slides, which damaged the plant. 

The trestles were filled beginning at the banks of the stream and work- 
ing back each way. On the made bank thus formed masonry piers were 
constructed, and a steel bridge of five spans was built over the main 
stream between them. 

The work has been planned and executed under direction of H. J. 
Gamble, Chief Engineer Pacific Division, Canadian Pacific Bailway, and 
bis Chief Assistant Engineer, Edmund Ducbesnay, of Vancouver, B. C, by 
whose courtesy the data concerning the work have been supplied. 

The class of work done on the Canadian Pacific Bailway described in 


tl]e foregoing pages is identical with that which is reqaired in dam- 
construction with similar materials, and the processes employed will be 
recognized by engineers as distinctly applicable in a treatise on the subject 
of hydraulic dam-building, the only difference being that in railway fills no 
attention is paid to such a distribution of materials as will secure the water- 
tightness of the bank and free drainage of percolating waters on its exterior 

Hydraulic Fills on the IfGrthem Pacific Eailway. — The cheap and effec- 
tive transportation of earth, gravel, rock, and sand and their deposit in 
embankment by water at a cost far below all other feasible methods, is the 
main principle involved, and this principle has been given further demon- 
stration on a large scale on the Northern Pacific Railway, in the State of 
Washington, during the years 1895-96-97. No less than fifteen high and 
dangerous trestles on the Cascade Mountain division have been replaced by 
hydraulic-made embankments of earth, gravel, and loose rock, washed from 
the adjacent mountainsides. The total amount of material thus moved 
aggregates 606,750 cubic yards, the average cost of which was 6.39 cents per 
cubic yard; or 5.82 cents for labor and 0.57 cents for materials. The lowest 
cost of any of the fills was 3.38 cents per cubic yard, everything included. 

The average cost of 377,000 cubic yards was 4.79 cents per yard, of 

which the detailed cost per cubic yard was as follows, figures which may be 

of special interest to those contemplating similar undertakings: 

Sluicing and building side levees 3.89 cents per yard. 

Hay used in side levees 0.09 " *' " 

Tools 0.08 " " '' 

Lumber and nails 0.22 '' ** " 

Labor building flumes 0.44 

Engineering and snperintendeucc 0.11 

Total 4T79 " " ** 

This work was done in the midst of a dense forest, where the ground to* 
be sluiced had to bo cleared, and stumps and roots necessarily interfered 
with the loosening of the material. All of the 377,000 yards were carried 
and deposited by water brought to the pits by gravity. In one case, how- 
ever, that of bridge 191, the water was supplied by pumping and 42,250 
cubic yards were moved by water thus lifted at an average cost of 13.5 cents, 
per cubic yard, the detail of which was as follows: 

Sluicing and building levees 10.81 cents per yard. 

Hay used in side levees 0.21 *' " " 

Tools 0.14 " " " 

Lumber and' nails 0.12 '' '' *' 

Labor building flumes 0.14 ** " " 

Coal used in pumping 1.87 " ** " 

Engineering and superintendence 0.20 " " " 

Total 13^ '' " *' 

(C (C cc 

<( (C (( 


The plan adopted on this work for disposal of the water after it had 
accompliBhed its duty was practically the same as that used at the La Mesa 
dam. A waste-box (or a number of them if the fill was a large one) was 
taken up through the body of the embankment, and built up a little at a 
time, as the filling increased in height. The top of the boxes was always 
kept lower than the side levees, so that the water could escape without 
orerflowing the sides as in the case of the Canadiau Pacific fills. Hay or 
straw was used for the aide lerees instead of brush or logs, which would 

Pig. C2.— Northern pAcryic BArt-WAV. Bridob 190. 

have cost cousiderablv more. In order to prevent the rapid wearing ont of 
the bottom of the fiumes a paving of square timbers was used, cut into 
3-incb blocks, so that the end would be presented as wearing surface. 

It was found that grades of 7^ and preferably 8^ were most advan- 
tageous for the sluicing-flumes to carry material containing considerable 
gmvel and rock, to prevent frequent blocking of the flumes. 

By courtesy of H. H. McHeury, uhief Engineer, and Charles S. Bihler, 
Division Engineer, Xorthern Pacific Railway, the writer has been furnished 
with the interesting photographs of the work (Figs. 52, 53, 54, and 55) 
which JUastrate the process of hydraulic filling very clearly in all its phases, 
and demonstrate with what precision embankments can thus be formed. 

112 RESERVOim hon jriuoaiioa; water-power, etc. 

The foUovring general description of Ibe work from the pea of Mr. Bihier 

" The resnlts have been rery gratifying, both aa to cost and character 
of the fills made. We are using, or trying to obtain, abont 100 inches of 
water for each nozzle, as with a leas qnaotity the rocky character of the 
material mored does not give good resnlts. Iq some cases we bare beeo 
able to obtain water at the bridge, witboot the necessity of building any 
ooneiderable length of flumes. In other cases we had to constract eereial 
miles of flumes for the water-snpply. These flames are constructed ia the 

Fia. 53.— NoHTBERN Pacific Railway. Bhidob 189, Cascade Mountaims. 

most temporary manner, of inch -and -a-qnarter lumber, 16 to 18 inches 
square. Wliere the locality would permit we have carried the dirt to the 
bridges to be filled a distance of over half a mile. The manner of bailding 
up the fill is very clearly shown in the photographs. We use hay for keep- 
ing up a levee on the onteide, and wooden frames or baffle-boards which are 
easily moved, to deflect the main cnrrent from the levees. The waste-water 
is taken oft through a waste-box which is taken np through the body of the 
flll and bnilt np as the filling increases in lieight. By adjusting the height 
of the waste-gate a larger or smaller amount of fine material can be retained 
in the fill, as desired. In building np the fill naturally a separation of the 


materiula takes place. The coarser material is deposited right onder the 
ead of the slnice-boxes, while the fiaer material is carried along toward the 
waste-boxes, the finest particles of each being deposited in the vicinit; of 
the waste-gate io the shape of mnd. For large embaakments it is therefore 
neoeeaary to hare several waste-gates, so that coarse material may be 
deposited, from time to time, at those places, and the accamulation of too 
mnch of the fine material at any one point may be avoided, 

" The plant reqnired for the work is rather inexpensive. According to 
locality, one nozzle woald require from 300 to 1000 feet of light eheet-iron 

Fio 54.— Northern Pacific Railway, Hydraulicfi 
Pit eaowma Hn>RAri.ic Giant m 

pipe, costing abont 37.5 cente per foot, and a No. 3 Giant, costing 195. 
Ontaide of this nothing is required escept picks, shovels, hoes, and axes. 

" The character of the material that we have available is not very favoi^ 
able. The pits are very rocky, and the banks overlying bed-rock which 
can be loosened by the water-jet are not deep. The cost given for slnicing 
and bnilding levee inclades all coeta of clearing. From five to six men are 
reqaired with each nozzle, to bnild the levee, move slnice-boxes, and do 
everything else connected with the work.'* 


Following is s sainmar; of the Tolnma sad coat of hydraulic filling s 
reported to date, ou the Northern Pacific Railway: 

Ai(rajt« Co«t p?r T«rd. 


8,200 ■' 



24.500 ■' 



BO.HOO ■' 



4,300 " 

10 55 


...J... S,100 '• 

13 23 


H»,80J " 



53.800 " 



800 •' 

80 21 


51.600 ■• 



..IW.IOO " 






4ii,a60 *■ 



The distinctive advantage recognized in favor of hydraulic filling cf 
trestles on railways is that it can be carried on withoat interruption to the 
traffic and withoat endangering the trestle, either by falling rocks or 
unequal settlement, and when it is completed no further settlement of the 
embankment can occur. The latter advantage applies with special force to 
dam-construction, and is one whose importance can scarcely be overesti- 
mated. Where the materials available consist of large and small stones, 
either angular or rounded with small gravel, sand, and silt, the ease with 
which these materials may be graded and assorted so as to permit the outer 
portion of the embankment to be built of the coarser rock where it will 
afford ready drainage, while the finer particles may be assembled in the 
center and inside where they will best resist percolation, constitutes a 
further advantage, which may well be considered as an efficient substitute 
for the ordinary puddle-wall of earth dams built in the usual manner. 


Seattle, Washington. — Except in the manner of loosening the materials 
and putting them in motion, the methods of hydraulic construction of 
embankment described in the foregoing pages are quite similar to those 
employed in the reclamation work done by the Seattle and Lake Washing- 
ton Waterway Co., at the city of Seattle, Washington. 

This work, however, has a totally different object, namely, the opening 
of navigable tidal channels by dredging and the reclamation of valuable tide- 
lands adjacent to the business center of the city, by filling them with the 
fine black sand dredged from the channels. Two powerful suction-dredges 
were used, each with a capacity of removing 6000 to 7000 cubic yards of 
solids per 24 hours, which was pumped from the bottom of the channel 
through 18-inch pipes, a distance of 2000 to 4000 feet, and deposited to a 
depth of 18 or 20 feet over the area to be reclaimed. Some 36,000,000 
cubic yards are to be handled in this way, and 1600 acres filled in solidly 
to a height of 2 feet above high tide. The actual cost of this class of work 
does not exceed two cents per cubic yard. 

The mean velocity maintained in the delivery-pipes was 13.6 feet per 
second, and the discharge was 24 second-feet, so that when the work was at 
a maximum the percentage of solids carried by the water was 9^, although 
tests have shown as high as 20^. The bulkhead along the channels which 
hold the sand in place is made of brush mattresses, while the temporary 
cross-levees are effectively formed by the use of coarse hay, straw, or swamp- 
grass, precisely as used on the Northern Pacific fills. 

Tacoma, Washington.— Hydraulic filling was done on a very large scale 
s few years since, at Tacoma, Washington, with salt water pumped from 
Puget Sound. The wharves in front of the city were located near the foot 


of a high blnff of glacial drift, and it was desired to fill a large area of 
lowland approaching the wharves, and substitate a portion of the wharves 
with an embankment of solid ground. To do this work the pumped water 
was piped against the bank, which was undermined, and the material 
carried to the place of deposit by the water. The cost of the work is repre- 
sented to have been very low, not exceeding six cents per cubic yard, aud 
the object sought was attained with entire success. 

Holyoke Dam, Massachusetts. — The Holjoke dam, across the Connecti- 
cut Biver, was built as a timber-crib structure 1017 feet long and 30 feet 
high. In 1885 the dam was reconstructed and filled with a mass of puddle- 
gravel, washed in and puddled by hydraulic streams, under direction of 
Mr. Glemeus Herschel, M. Am. Soc. 0. E., of which he writes:* ''No 
part of the work gave less anxiety and more satisfaction than this from the 
day it was started.'' Referring to similar work Mr. Herschel again writes: f 
^' Pure grayeU just as it comes from the gravel-pit, will make a water-tight 
stop, when used between planks, or in any other position for which puddle 
is used, as far as my experience goes, better than clay or a clay mixture 
ever did." 

Georgia. — In the course of an extended experience in hydraulic mining 
on the Etowah River, in Georgia, Col. Latham Anderson, M. Am. Soc. 
G. E., demonstrated that '* Gravelly hydraulic tailings coald be deposited 
within sharply defined limits and in any shape desired, limited only by the 
condition that the slopes should not be steeper than the natural repose of 
the material." (Private letter to the writer.) 

Utah Experiments. — The experiments made by Prof. S. Fortier, of the 
Utah Agricultural College Experiment Station, on the mixture of yarlous 
aggregates for use in construction of earthen dams, shows that gravel, sand, 
and clay will occupy less space and become more compact when poured into 
water, mixed therewith, and allowed to drain and settle, than by any 
process of tamping either moist or dry.| 

These miscellaneous citations safficiently illustrate the principles and 
methods that may be successfally employed, in any locality where natural 
conditions are favorable for the construction of dams, safely, cheaply, and 
efficiently by the powerful and convenient aid of flowing water. 

 Trans. Am. Soc. Civil Eng., vol. xv. p. 568. 
; t -/Wd., vol. xxvi. p. 684. 
X Earthen Dams, by Samuel Fortier; Bulletin Uiah Agricultui-al College, No. 46, 
Nov. 1896. 


The character of stmcture which appeals most effectively to the 
majority as worthy of confidence in its ability to withstand water-pressnre 
and the action of the elements for ages is nnqaestionably the masonry dam, 
founded on solid rock and built up as a monolith between the natural rock 
buttresses of a gorge, with Portland-cement mortar. Such a structure 
invariably commands greater respect and confidence in the public mind 
than any other. It may not in certain cases actually be safer from ovlr- 
tuming or better able to resist the strains and forces tending to rupture it 
than well-built dams of w(>od, earth, or loose rock, but it usually has the 
appearance of strength; and the moral effect of a dam of that character 
upon the public, as well as upon investors in securities dependent upon the 
stability of dams and the permanence of the water-supply retained by them 
in reservoirs, is one which cannot be disregarded. 

That masonry dams are not built in every site is due to the fact that 
the foundations are not always suitable, and surrounding conditions often- 
times render their cost prohibitive. 

Masonry dams are distinct from buildings, arched bridges, and other 
masonry structures in that the best class of masonry as ordiuarily applied 
and used is not best adapted to dam-construction. Gat-stone masonry or 
ranged ashlar, while more expensive and of greater strength than, is not so 
suitable for masonry dams as, random rubble, laid regardless of beds or courses, 
homogeneous concrete, or a combination of large irregular masses of stone 
embedded in concrete — a rubble-concrete, — either of which is much 
cheaper. The strains in a dam are in various directions, whereas ranged 
ashlar, laid in horizontal courses, is best adapted to resist the forces acting 
perpendicular to those courses, and not those having the same horizontal 
direction. The dam should therefore be made as nearly homogeneous and 
monolithic as possible, and the stones used thoroughly interlocked in all 
directions, avoiding the horizontal courses of ordinary cut-stone masonry. 

While masonry dams have been built antedating the Christian era, and 
some very notable ones were constructed in Spain for irrigation -storage 
more than three hundred years ago, it is only within the past fifty years 



thafc the correct theories of the straios to which sach stractares are snb- 
jected, and the proper proportions to be given them to secare stability 
uader all conditions, have been reduced to some degree of mathematical 
certainty. The Spanish dams built in the sixteenth centnry were massive 
blocks of masonry, almost rectangular in form, containing a large surplus 
of material beyond actual requirement, but so unscientifically disposed as to 
produce maximum pressures dangerously near the point of crushing. 

The French engineers who were required by the French Oovernment to 
prepare plans for high masonry dams for the control of floods on torrential 
rivers in southern France about fifty years ago, were the first to advance 
new ideas and practical theories on the principles that should govern the 
design of these structures. M. Sazilly prepared a paper on the subject in 
1853, and a few years later the matter was more fully elaborated by 
M. Delocre, on whose formala were drawn the plans for the great Furens 
dam, 183.7 feet high. In 1881 Prof. W. J. M. Rankine, the noted English 
engineer, was called upon to report on the best form of masonry dam to be 
bailt for the city of Bombay, India, and investigated the question in a 
tliorongh mathematical way, producing a form of profile which is recog. 
nized as one of the most logically correct in its conformity to all requisite 
conditions. He established as one of the governing principles that no 
tension strains should be permitted in any part of the masonry, and that 
therefore the lines of resultant pressure, with reservoir either full or empty, 
should fall within the inner third of the dam at all points. The acceptance 
of this principle carries with it as a necessary sequence that the maxima 
pressures will fall below safe limits, whereas if the dam be designed with 
regard to safe limits of pressure alone the structure may be so slender as to 
carry the lines of pressure far beyond the center third and thus set up 
dangerous tension in the masonry. 

Other prominent English engineers who have investigated the subject 
are Mr. Guilford L. Molesworth and Mr. W. B. Coventry. 

Mr. H. M. Wilson, Assistant Hydrographer, U. S. Oeological Survey, in 
his '' Manual of Irrigation Engineering," devotes a long chapter to an ad- 
mirable discussion of masonry dams, while the most recent American treatise 
is the elaborate work entitled '' The Design and Construction of Dams," 
by Edward Wegmann, C.E., of which the fourth edition was issued in New 
York in 1899. Mr. Wegmann has rendered invaluable service to the pro- 
fession in the investigation of the difficult problems involved in the design 
of masonry dams, and in simplifying the mathematical formnlsB for com- 
puting the economical safe proportions of such structures. 

The general principles to be considered in designing such a dam are 
briefly as follows : 

(1) That it must not fail by overturning. 

(2) That it must not slide on its foundation or on any horizontal joints. 


(3) That it must not fail by the crashing of the masonry or the settle- 

ment of its foundation. 

(4) That it mast be equally safe from excessive pressure upon the 

masonry whether the reservoir be fall or empty. 

(5) That certain known safe limits of crashing of masonry of the class 

to be nsed shall not be exceeded. 

Masonry dams may resist the thrast of water-pressure either by their 
weight alone or by being bailt in the form of an arch, which will transmit 
the pressures to the abutments. The first of these two classes of structure 
is called the gravity dam. The second is the arch dam, and it may be 
either of the gravity type in arched form, or it may depend upon its arched 
form alone. In either case the weight of the dam must be borne by the 
foundations, and these must be of the best quality of solid bed-rock. 
Everything of a friable nature should be removed, and the excavation so 
made as to leave the surface rough, to avoid the possibility of the dam 
sliding on its base. The maxima pressures permissible should not exceed 
15 tons per square foot, and may require to be as low as 6 tons per square 
foot. For very high dams it is essential that they should diminish in thick- 
ness as the top is approached, else the masonry might be crashed and fail 
of its own weight. This consideration suggests the simple triangle as 
theoretically correct, with certain modifications. The thrust of the water 
tends to overthrow the dam by revolving it around its lower toe, and hence 
there is such a concentration of water-pressure and weight of masonry at 
that point as to necessitate a sufficient width of base to confine the resultant 
of these forces inside the outer toe-line of the wall, and avoid the crashing 
of the masonry by distribution of the strains over a greater area. If the 
hypothenuse of the right-angle triangle were presented to the water as the 
upper face of the dam, the forces acting perpendicular to that face would 
give the wall greater stability from overturning, if the structure were con- 
sidered as a rigid body incapable of being crushed. On the contrary, if the 
vertical side of the triangle be presented to the water, the dam, while less 
liable to be overturned, is more capable of resisting fracture or crushing, 
the pressures are more evenly distributed over its base, and the foundations 
less likely to yield. 

While the simple triangular form of dam, of such base-width that the 
lines of pressure with reservoir full or empty fall within the inner third, 
amply fulfills the requisite conditions to resist the quiet pressure of water, 
in practice it is necessary to give a certain definite width to the top of the 
dam to enable it to resist wave-action and ice-thrust. In dams 50 feet high 
or less this top width need not exceed 5 feet; for dams 100 feet high the 
width need not be more than 10 feet, and for a height of 200 feet a width 
of 20 feet is considered ample. Greater widths are given where the top of 
the dam is to be used as a roadway. The crest cf the structure should also 



be raised a certain elevation above the highest water-level to provide for 
extreme floods. This superelevation will necessarily be governed by the 
size of the spillway provided and the area of watershed tributary, bat 
ordinarily it should be limited to about 10 feet at the extreme. 

High reservoir dams erected across large streams, where conditions da 
not easily permit of the construction of a spillway to carry the water around 
them and it is necessary to permit the passage of floods over their crest, are 
subjected to shocks due to the weight of water falling upon the toe of the 
dam, which cannot be computed accurately and for which no formulae have 
been deduced. In cases of this kind it is customary to allow a substantial 
addition to the dimensions given by the theoretical profiles deduced from 
the formula for gravity dams under qniet pressure, and to provide a water- 
cushion at the toe of the dam by the erection of an auxiliary wall a little 
distance below. The lower face of the dam should also conform as closely 
as possible to the natural curves assumed by the falling water. 

Curved Dams. — While there is an essential general agreement among 
engineers as to the theoretical profile best adapted for gravity dams, there is 
a wide difference of opinion as to the effect of the value of the arch in 
adding stability to the dam. That such stmctures can and do successfully 
transmit pressures laterally to the abutments is proven by the Bear Valley, 
the Zola, and the Sweetwater dams (Fig. 56), the three highest and most 


^*. . . . 


SeAR yAd.l£.r^A^ 

ZOIA £?A/^ 

^rrssrrrAr£A Oam 

Fig. 56. 



noted types of arched dams in existence. The Bear Valley and Zola dams 
are so slender in profile as to be absolutely unstable were they built straight, 
while the Sweetwater dam, though more nearly approaching the gravity 
type, is of such proportions as to be theoretically unstable as a gravity dam, 


although it has Bnccessfally withstood the shocks of an enormoas flood 
poaring o^er its crest; for nearly two days. 

M. Delocre has said that a cnr\red dam will act as an arch if its thick- 
ness does not exceed one-third of the radios of its upper face, while another 
eminent French engineer, M. Pelletrean, considers that it will so act pro- 
vided the thickness be not greater than one-half the radius. Mr. J. B. 
Krantz maintains that a radius as small as 65 feet is essential to permit a 
dam to act as an arch and transmit water-pressure to the sides. AH 
engineers appear to agree that the mathematics of curved dams are extremely 
uncertain, and irreducible to a satisfactory demonstration. It is un- 
doubtedly true that in a narrow gorge a considerable saving of masonry 
might be made by constructing the dam as an arch, with equal stability to 
one of gravity type built straight. M. Delocre is of the opinion that in no 
situation is it necessary for a curved dam to be of greater thickness at any 
point than the width of the valley at that height. The principle now 
generally adopted as safe is to make the structure strong enough to resist 
water-pressure by its weight, and curve the form as an additional safeguard. 

The curving of all dams of whatever length or height regardless of 
whether they may act as an arch or otherwise for the purpose of enabling 
them to better resist the tendency to vertical cracks due to variations in 
temperature, especially in countries subject to climatic extremes, is coming 
to be recognized as of sufficient importance to lead to its general adoption. 
In this connection the following. quotation is taken from the remarks of 
Prof. Forchheimer of the Aix la Cbapelle Polytechnic School, Germany, in 
discussing a paper read by Mr. George Farren, before the Institution of 
Civil Engineers, in 1893, on '' Impounding Reservoirs."* Referring to a 
dam 82 feet high, plastered and rendered over with two coats of asphalt, 
built by Prof. Intze in Remscheid, Westphalia, Prof. Forchheimer says: 

^'A backward and forward movement, amounting to 1^ inches, 
occurred during the filling and emptying of the reservoir, and the move- 
ment due to temperature was almost as great as this. The latter was due 
less to the temperature of the air than to direct solar radiation. The crest 
of this dam was 460 feet long and was arched with a radius of 420 feet. 
One side was exposed to the sun longer than the other, and the more exposed 
part moved to and fro seven-eighths of an inch in the course of the year, 
while the other part moved only one-eighth of an inch, the crest expanding 
one nine-thousandth of its length, or five-eighths of an inch. In arched 
dams such movements do no harm, but in straight dams these phenomena 
are objectionable. As dams are usually built during the warmer seasons of 
the year, the masonry has a tendency to contract in the colder weather. 
In a curved dam this can take place by movement of the structure without 
cracking, but not in a straight dam. ... If the temperature is lowered 

* Proc. Inst. Civil Eng., vol. cxv. p. 156. 


10^ C. (18° F.) and it is DOt free to contract, tension amoantiug to betweea 
140 and 280 pounds per square inch is set up, which is greater than the 
mortar will stand. . . . That a straight, or almost straight, wall incurs- 
considerable danger of fracture is shown by practical experience. Th& 
dams of Habra, Grands-Cheurfas, and Sig, in Algiers, have broken, and in 
that of Hamiz a tear occurred during tbe first filling. The Habra dam 
broke in December, and the Grands-Cheurfas and Sig dams gave way in the 
month of February. The Beetaloo dam, in Australia, also developed a. 
crack one-eighth of an inch wide in the middle of winter without any 
apparent cause. The Mouche dam, Haute Marne, a structure 1346 feet 
long and about 100 feet high, exhibits clearly the dangers attending 
straight dams. In the winter of 1890-91, when tbe temperature varied 
between - 10° C. and — 20° 0. (14° to — 4° F.) and the water-surface 
was 10 feet 8 inches below the normal level, seven vertical cracks appeared 
in the dam, situated at uniform distances of about 160 feet apart. They 
were widest at the top, and died out about 37 feet below the normal water- 
level. Their aggregate breadth was 2^ inches. The cracks gradually closed 
as the temperature rose, and by the end of February, 1891, four of them 
had completely vanished, while the others had perceptibly contracted." 

It has been the observation of the writer that all carved dams are free 
from cracks, but that straight reservoir walls are quite certain to crack. 
The tendency of the water-pressure is to close any cracks that may appear 
where the dam is curved, and a curved dam is able to take up the move- 
ment due to temperature, without cracking, even though the pressure may 
not cause the arch to come in action. The inference is that every masonry 
dam should be built in the form of an arch, whatever its profile may be,, 
for the avoidance of temperature cracks. 

Mr. H. M. Wilson says: * '^ An additional advantage of the arched form 
of dam is that the pressure of the water on the back of the arch is perpen- 
dicular to the up-stream face, and is decomposed into two components, one 
perpendicular to the span of the arch and the other parallel to it. The 
first is resisted by the gravity and arch stability, and the second thrnsts the 
up-stream face into compression, which has a tendency to close all vertical 
cracks and to consolidate the masonry transversely. An excellent manner 
in which to increase the efficiency of the arch action in a curved dam la 
that employed in the Sweetwater dam. This consists in reducing the^ 
radius of curvature from the center towards the abutments. The good 
effect of this is to widen the base or spring of the arch at the abutments, 
thus giving a broader bearing for the arch on the hillsides. The effect of 
this is seen in projections or rectangular offsets made on the down-stream 
face of the dam, the center sloping evenly, while the surface is broken by 

* Manual of Irrigalion Eoglneering, pp. 390, 391. 


steps when it abuts against the hillside. . . . Though the cross-section 
of a carded dam may anqaestionably be somewhat reduced, it would be 
unsafe to reduce it as much as has been done in the case of the Bear Valley 
and Zola dams, though these have withstood secnrely the pressures brought 
against them. It might with safety be reduced to the dimensions of the 
Sweetwater dam, thus saving largely in the amount of material employed." 


Old Mission Dam, San Diego, Cal. — The first masonry dam built in 
California of which there is any record was erected in 1770 by the Jesuit 
Mission Fathers. It was constructed across the San Diego Biver, 13 miles 
above its mouth, at the lower end of El Cajon Valley, where the stream 
cuts through a dike of porphyry. It was built for impounding and diverting 
water for irrigation and domestic use at the San Diego mission 4 miles 
below. It was 244 feet in length, 13 feet in thickness, and about 15 to 18 
feet high. Fig. 57 is a recent photograph of the old dam in its present 
condition, half buried in trees and driftwood. The view is taken below the 
main outlet-sluice. The water was conveyed to the mission through an 
open masonry conduit, lined with semicircular tile or half-pipes. The 
cement used in the dam was made from limestone possessing hydraulic 
properties, quarried near the dam. The dam, though still in existence, has 
been disused for half a century past. It shows evidence of having been 
damaged by floods and repaired at various times. The manual labor of 
construction was done by Indians, of whom no less than 1600 neophytes 
were at one time supported at the mission. Considering the quality of the 
materials and labor available, and the torrential nature of the river, which 
it has resisted, as evidenced in the photograph by the driftwood piled up 
against it, the masonry is of excellent grade. 

El Molino Dam. — A few years after the erection of the Old Mission dam 
of San Diego the Jesuit Fathers constructed a masonry wall of similar size 
about 10 miles east of Los Angeles, the purpose of which was to control 
and raise the level of a natural lake and impound it for use in irrigation at 
the Mission San Gabriel. The dam is located on what is now known as £1 
Molino rancho, the name being derived from the fact that the priests here 
built a mill, whose massive walls are still intact, for grinding corn and 
wheat, the power for which was deriyed from water gathered from springs 
that issued from the hillside and fed the lake. The mill was a little above 
the level of the crest of the dam, and the water from the wheels flowed into 
the reservoir, where it was caught for use in the valley below. The dam 
was straight in plan, about 200 feet long, and 15 feet high at the center. 
The masonry is of superior character and is still in perfect state of preserva- 
tion, although it has not been in service as a dam for many years past. 


The Sweetwater Dam. — This stmctare is located ia the Sweetwater 
Biver, 7 miles above the mouth of the stream aad 12 miles southeast of the 
city of San Diego, California, and was bailt in 1887-88 by the San Diego 
Land and Town Company to impound water for the irrigation of lands 
bordering on the bay of San Diego and for the domestic supply of National 
City. The Sweetwater, like all the so-called rivers of San Diego County 
that empty into the Pacific Ocean, is a torrential stream, subject to violent 
floods in seasons of abundant rains, and dwindling to a diminutive brook 
within a few weeks or months after the rain ceases. During the summer 
and fall it ceases to flow, and on occasional years of low rainfall the run-off 
even in winter is practically nothing, so that it was essential to provide 
storage for at least two years' supply for the territory depending upon it. 
Prior to the beginning of work nothing was known of the probable run-off 
to be expected, further than that the watershed area of 186 square miles, 
having an extreme elevation of about 6000 feet, would probably receive a 
precipitation very greatly in excess of the recorded rainfall at San Diego, 
where the record has been maintained for nearly forty years, and that 
judging by this record the run-off from such a watershed should give an 
average supply adequate to the needs of the community to be provided, 
with a storage capacity of two years' supply in the reservoir. Subsequent 
experience has shown that the fluctuation in run-off has ranged from prac- 
tically nothing for three consecutive years to 70,000 acre-feet in one year, 
or nearly four times the reservoir capacity, per annum. At the time the 
construction of the dam was begun in November, 1886, an active land 
*' boom " was in progress in southern California, and the San Diego Land 
and Town Company, owning a large area of fertile lands, found them 
unsalable without water. It was essential, therefore, to obtain a certain 
portion of the supply quickly in order to market the lands. The dam was 
thus necessarily planned without the usual preliminary studies of its 
capacity for storage, or the volume of supply which would be required or 
could be made available. 

As originally designed, the dam was to be a slender masonry or concrete 
structure, fashioned after the Bear Valley dam by the same engineer who 
built the latter, and was to be but 10 feet thick at base, 3 feet at top, and 
50 feet high, backed on the water-face by an embankment ^f quicksand. 
When the wall had reached a height of 15 to 20 feet at the highest part, at 
an expenditure of $35,000, and its outline and design were fully realized by 
the management, the plan was disapproved and the writer was engaged to 
construct a more substantial work on the same site, utilizing the masonry 
already in place. The new plan was drawn to have an extreme height of 
60 feet, and the new work enveloped the old. This structure is shown 
nearly complete in Fig. 58, and its profile is shown in dotted lines in the 
middle section on Fig. 59. It was built in steps onthe back with a view to 


Fio, BB.— Eij:vatiom and Skctions of Swektwateb Dam. 


ndding to its height, as was Bnbseqaetitl; don«. The dam had a masimum 
thickness of 35 feet at base, and vaa 5 feet think at the top. It was forti- 
fied by aa embankment of cla; and gravel 50 feet wide, 10 to 15 feet high. 

Fio. «0 — Pacb ok Swbbtwatkr Dam in 1899. Afteii Two Years of Drouth. 

placed against the npper side and well tampeil in place. A portion of this 
embankment above the water-line is shown in Fig. 00, a view taken in the 
summer of 1899 when the reservoir was practicallv empty. 

Shortly before the completion of the (iO-foot diim authority was given 
for its extension to 00 feet in height, on the recommendatioa of the writer, 
whose surveys had revealed the fact that the re!<erTDir capacity conid be 
increased nearly fivefold by snch addition of 30 feet to the height. Accoril- 
ingly excavation was renewed at the lower side for an e^cteneion of the width 
of the base, and work proceeded on the final plan without interrnpLion 
nntil the completion of the entire structure in April, 18S8. The conEirnc- 
tiou occupied sixteen months in all, including two months of waiting for 
cement. The profile adopted is shown in Fig. 59. As finished the dimen- 
sions were the follotving: 

Length on top 380 feet. 

" at base 150 " 

Thickness at base 40 " 

" top 13 " 

Height on upper side exclusive of parapet 90 " 

Height on lower side !>8 " 

Radius of arch 222 " 


The np-stream face has a batter of 1 to 6 from base to within 6 feet of 
top; thence vertical. The lower slope has a batter of 1 in 3 for 28 feet» 
then 1 in 4 for 32 feet, and thence 1 in 6 to the coping. 

Water is drawn from the reservoir through a tower of hexagonal form^ 
placed 50 feet above the dam, near the center (see Fig. 61), and connected 
with the dam by a foot-bridge of iron (see Fig. 62). 

It has seven inlet-valves which are placed at intervals of 10 feet in 
height from the top down. Two cast-iron outlet-pipes, 18 and 14 inches 
diameter respectively, lead from the tower to and throngh the dam. They 
lie in a trench cut in the bed-rock, and on top of them is built a masonry 
conduit from the tower to the dam, connecting with a third pipe, 36 inches 
diameter, of riveted wrought iron, ^ inch thick. All are carefully 
embedded in the masonry of the dam, and no leakage has ever taken place 
along them. Gate-valves control their flow below the dam. The tower 
valves are simple plates of cast iron fitting over elbows set in the masonry 
of the tower, and can only be moved when the lower gates are closed. 

The stone used in construction was quarried from the cliffs on either 
side below the dam, within a distance of 800 feet, and was all hauled in 
wagons and stone-boats. Animal power was alone used for manipulating the 
derricks in the quarry and on the dam, as well as for mixing concrete. 
The stone was a blue and gray porphyry impregnated with iron, weighing 
175 to 200 pounds per cubic foot. It quarried out with irregular cleavage, 
but generally presented one or two fairly good faces. The seams in the 
rock contained plastic red clay to such an extent that it was necessary to 
wash and scrub by hand every stone that went into the dam with good steel 
and fiber brushes. Imported English and German cement was used 
throughout the work, mixed with clean, sharp river sand in a revolving 
square box of wood, with a hollow shaft passing through two diagonally 
opposite corners, throngh which the water was introduced. The masonry 
weighed when tested 164 pounds per cubic foot. 

The waste-weir is formed at the left bank as a part of the dam, and as 
first built consisted of seven bays, each 4 feet in clear width, closed with 
flash-boards, which could be opened to a depth of 5.7 feet below the crest 
of the dam. These bays were separated by masonry piers, each 2 feet in 
thickness. This wasteway and a 30-inch blow-off gate from the main pipe 
below had a combined capacity of 1300 second-feet, which was in excess of 
the maximum flood discharge as indicated by high-water marks, although a 
subsequent flood exceeded this capacity a little more than ten times. 

The volume of masonry in the dam proper, including the parapet 3.5 
feet high, 2 feet thick, was 19,269 cubic yards. The wasteway, inlet-tower, 
and other accessories required 1238 cubic yards additional, or a total of 
20,507 cubic yards of masonry, in which were used 17,562 barrels of 

132 ssiaBiiroiiis for irrigation, water-pgwbr. etc. 

Fio. W,— Dbtailb of Towes of Swkktwatkr Dam. 


cement, an average of 1.17 cubic yards per barrel. The total cost was 
t234,074.11, divided as follows: 

Plant $6,236.76 

Materials 87,431.70 

Labor 140,405.65 

Total $234,074.11 

The reservoir capacity formed by the dam was 5,882,278,000 gallons or 
18,053 acre-feet, of which 80^ is within the npper 30 feet, and 40^^ in the 
last 10 feet. The area covered at high-water mark was 722 acres, of which 
300 acres was cleared and grabbed at a cost of $10,808.46, or about $36 per 
acre. The average depth of the reservoir is 25 feet. 

Enlargement. — On the 17th and 18th of January, 1895, the Sweetwater 
dam SQCcessfully withstood a test far more severe than is usaally imposed 
on reservoir walls of sach comparatively slender dimensions (thaoks to the 
painstaking care exercised in its original construction), and beyond any 
previous calcalation or expectation. On those dates the reservoir was filled 
to overflowing by a flood resulting from a rainfall of more than 6 inches in 
24 hours, and for forty hours the dam was submerged to a maximum depth 
of 22 inches over the parapet wall, with the wasteway and blow-off gate 
wide open. This was 5. 5 feet higher than the water had been expected to 
rise in extreme floods, as it had not been considered possible for the crest 
of the parapet to be reached. 

A gap in the ridge to the south of the reservoir, the crest of which was 
about level with the parapet, carried off quite a large additional volume at 
the extreme of the flood. The maximum rate of discharge during the flood 
was carefully computed by Mr. H. N. Savage from weir measurement, and 
found to be 18,150 second-feet, a rate of discharge which was maintained 
for one hour. 

This extraordinary freshet, which within a week produced a run-off of 
nearly three times the capacity of the reservoir, was gratifying in one 
respect, in that it demonstrated the ability of the dam to cope with such 
emergencies, as not a stone of the masonry was disturbed or moved from 
place, although so much damage was done to the pipes and surroundings of 
the dam as to necessitate a large expenditure in repairs. The water-supply 
was cut off from consumers for more than a month before a partial restora- 
tion could be made. 

Advantage was taken of the opportunity afforded by the general repairs 
to make a material enlargement of the reservoir capacity by virtually raising 
the permanent high-water level to the point it had assumed during the 
flood, and at the same time preparing the dam for receiving a repetition of 
such an experience by enlarging the wasteway and fortifying the weak 
points developed by the flood. 


The freshet caused a tremendous erosion of the bed-rock on either side 
of the dam, particularly in front of the spillway discharge, where the strata 
were inclined at about the proper angle to enable the water to strip off layer 
after layer with surprising rapidity. It was estimated that no less than 
10,000 cubic yards of the solid rock on that side were torn away and washed 
down-stream, and some 2000 yards from the opposite wall of the canyon. 
The approach of a disused tunnel below the spillway, which was some 25 
feet long, and about 30 feet of the tunnel itself, in solid rock, were cut off 
and the surrounding rock washed away. This tunnel had been opened 
some years before to draw down the reservoir, in compliance with the order 
of the United States Circuit Court, in the famous litigation over the con- 
demnation of lands in the reservoir-basin, and terminated directly in front 
of the spillway channel. The bombardment of the stones rolled down the 
canyon during the flood upon the pipe-line resting on one side and covered 
with masonry, destroyed it for a considerable distance down-stream, as well 
as the railway track leading to the dam. 

The repairs to the dam, and the general improvements designed, were 
completed in the summer following at a cost of $30,000, under the capable 
direction of H. N. Savage, chief engineer, the writer acting as consnlting 
engineer during its progress. The alterations made were the following: 

1. The parapet of the dam was raised 2 feet and strengthened, so as to 
permit of permanently holding the water in the reservoir as high as its 
crest, leaving 200 feet in the center as a weir, 2 feet deep. This weir was 
arranged with cast-iron frames carrying flashboards, to be removed in 
extreme floods, as shown in Fig. 66. 

2. The spillway was extended in length by adding four more bays, each 
5 feet wide, and carrying all the bays np to the level of the new crest of the 
dam, giving it a maximum depth of 11.2 feet and a discharging capacity of 
5500 second-feet. 

3. The unused tunnel, 8 by 12 feet in size, the bottom of which at the 
heiwi is 50 feet below high-water mark, was adapted for use as an additional 
spillway discharge, by laying four pipes through it on a 4^ grade, two or' 
which are 36 inches and two 30 inches in diameter, all arranged with valve 
covers over elbows at their upper ends, where a shaft, reaching to the sur- 
face on the line of the dam, gives means of control (see Figs. 68, 69, and 
70). Further control is had by gate-valves set in the pipes directly below 
the masonry bulkhead built across the tunnel at the shaft, all the pipes 
passing through this bulkhead. In the summer of 1899, when the reservoir 
was empty, the head of this tunnel was protected by a concrete portal with 
an inclined grillage of iron rails to keep out drift, as shown in Fig. 70. 

4r. The eroded rock slope below the wasteway after being made uniform 
was covered with a grillage of iron rails embedded in concrete, which has a 

Fio, 66.— Kbpaihiko akd 


thicknesa of 3 feet, and ia deeigned to prevent all fatnre eroeion of the bed- 
rock (FigB. 65 and 69). 

5. A ceucrete wall 15 ieet high, 18 inches thick, with counterforts of 

i!ia. vi 

— rLAN ow 




-Jl   " 


U A 

\ ; \. 

Fig. 68.— Profile 

Plas ot Wabtkwat Tn wN EL. 

15 feet base, was built from bed-rock 50 feet below the dam on a cnrve 
concentric with it, to form a water-cashion or pool in case of a future over- 
flow. This is shown in plan in Fig, 67. 



6. The main snpplj-pipe vaa replaced throngh the canyon in a Bolid 
rock cut u portion of the way, and protected thronghottt the canyon by 
concrete collars and covering and spnr walls, all with iron rods incorporated. 

At the same time a new steel pipe-line, 24 inches in diameter, which 
va8 partly luid when the dood occurred, was completed to I^ational City on 

Fm. 70— SwEKTWATBU Dam, bbowino Head of Outlet Tdknbl ahd Spiliwat. 

the north side of the valley, as a high-level conduit. This was connected 
with and took supply from one of the 30-1 rich-diameter pipes built in tJie 
tannel, and connected with the original distrihution system at National 
City, thus giving two independent conduits. 

The eSect of raising the parapet wall in the manner described has been 
to raise tbo height of the reservoir 5.5 feet and increase its capacity about 
%b%, or from 18,053 acre-feet to 32,5f>6 acre-feet. The dam having shown 
its ability to withstand this increased pressure, it is now proposed to make 
ibis addition to the reservoir a permanent feature of the works. 

Concrete was nsed in all the new work, ns preferable to rubble masonry, 
because of the greater ease with which all the materials conld he handled 
and because of the fact that the work conld be performed by unskilled labor 
nndor intelligent foremen. The concrete was mixed with a rotary Ransome 
mixer, one of the best machines for the purpose yet devised. A steam 
hoisting-engine furnished all power required for rock-jrnshiog, actaating 
the mixer, and hoisting the concrete to the top of the dam, where it was 
distributed by wheelbarrows. Old rails and scrap bar-iron of all sizes were 
embedded in the concrete wherever it would add desired reinforcement to 
the strength, as in the 6-inch floors of concrete forming the foot-bridge 


over the wasteway, Bpanning the 5-foot spaces between piers; in the roof of 
the gate-hoase over the shaft in the tnnnel from which the heavy gates are 
saspended, and in the floor of the house; in the carved wall forming the 
auxiliary water-cushion dam, which is 10 to 15 feet high, and but 18 inches 
thick, and in the inclined apron of the wasteway. This construction is 
quite satisfactory, and shows no cracks anywhere. The rates of expansion 
and contraction of iron and concrete under changes of temperature are 
practically identical, and no separation of the two elements can occar by 
such changes. 

There are no visible e?idence8 of cracks in any of the masonry of the 
dam, nor any indications of a tendency towards crushing at the toe of the 
dam. This may be due to the fact that the stone is extremely hard and 
strong, and the mortar of prime quality. It may be further owing to the 
fact that arch action has resisted pressure from the top down to some 
neutral point where gravity alone suffices. There have never been any 
spouting leaks to indicate the transmission of an upward pressure upon the 
masonry of the slightest moment The leakage through the wall was never 
of considerable amount, and has steadily diminished, so that when full the 
wall is practically dry over most of its outer face. 

This leakage was reduced in amount in 1890 by carefully repointing the 
inside face as far down aa the water was lowered in the reservoir, about 60 
feet below the top, and applying successive washes of potash-soap and alum- 
water alternating. 

Protracted litigation followed the building of the Sweetwater dam, over 
the attempted condemnation of a tract of about 300 acres of land at the 
upper end of the reservoir-basin, submerged by the impounded water. The 
land was comparatively valueless for agricultural purposes, but a jury gave 
an exorbitant judgment of its value on testimony erroneously admitted as to 
its special adaptability for reservoir purposes. This litigation lasted several 
years and was finally compromised, but the effect of it was quite disastrous 
to the progress of the country depending upon it for irrigation. During the 
progress of this litigation a tunnel, heretofore referred to, was opened 
around the south end of the dam, at the level of 25 feet above the lowest 
outlet, by means of which the flooding of the land could be avoided. In 
obedience to an order of the United States Circuit Court the reservoir, 
which had been flUed, was ordered emptied, and an enormous volume of 
water was thus wasted at a time when it was greatly needed for irrigation. 

Including the period of retarded growth during the progress of litigation 
the dam has been in service for thirteen irrigation seasons, during which 
time the impounded water has created values aggregating several millions 
of dollars, reckoning all improvements made in the district directly 
dependent upon it for water-supply. The area irrigated from it is now 
4580 acres, chiefly planted to citrus fruits, of which the greater part is 



devoted to lemonB. A popnlatioQ of 2500 to 3000 people is dependent 
apon the reservoir for domestic water. The distribation for irrigation as 
well as for domestic use is entirely by pressare-pipes, and the agricaltaral 
community is as well equipped for fire-pressure and general water-supply as 
the average American city. All water for irrigation, and practically all 
domestic water, is measured by standard water-meters. The pipe system 
has cost in the aggregate some $800,000. 

Eun-off of Sweetwater Eiver. — The area of watershed above the Sweet- 
water dam is 186 square miles, ranging in elevation from 220 feet above 
flea-level, which is the elevation of the top of the dam, to about 5500 feet 
at the summit of the mountain-range in which it heads. The mean eleva- 
tion of the basin is probably about 2200 feet There is practically no 
diversion of the stream above the reservoir, and no utilization of its water 
other than that of the dam. Hence the catchment at the reservoir repre- 
sents the entire run-off of the shed. A careful record of this run-off has 
been kept since the construction of the dam. Its extremely yariable 
character is shown by the following table: 

Tablb of Mbascred Run-off, Sweetwater Drainage-basin. 

Area 186 square miles. 


Rainfall at 

Sweetwater Dam. 


Run-off as 

measured at the 



Average Yearly. 

Ruii<off in 


per [Square Mile. 

Average Annual 




































































Mean for 18 jrs.. 



Of the entire period of tweWe years recorded the ran-off has exceeded 
the capacity of the reservoir in bat foar seasons. The remaining eight 
reasons have been so far below the fall reservoir-capacity in yield of stream- 
flow as to jastify the recommendation made by the writer on the completion 
of the dam that a fall reservoir should always be considered as a two-years' 
sapply, and that no more than one-half its capacity should be used in any 
one season. The percentage of probable mean rainfall which this run-off 
represents is remarkably small, in view of the mountainous and precipitous 

160 BEaEBVoma fob ibbiqation, wateb-poweb, eto. 

character of a considerable part of the draiDage-basia. The mean rainfall 
of 1894-95 was estimated at 27.14 inches, of which the ran-off was bat 
26^. The following year, with an estimated mean rainfall of 16 inches the 
ran-off was bat six-tenths of 1^. This illastrates the great yariation ta 
which sach streams are subject. When the rainfall in the lower two-thirda 
of the basin does not exceed 12 inches it is all absorbed in plant-growth and 
evaporation from the soil and does not feed the stream except when it comea 
in violent storms. Under such conditions the apper third of the basin 
supplies all the ran-off, and if that portion does not receive more than 18- 
to 20 inches, the stream-flow is very small and of short daration. The 
record of catchment at the Guyamaca reservoir, whose watershed is all on 
the monntain-top from 4800 to 6500 feet in elevation, adjoining the upper 
portion of the Sweetwater shed, clearly shows that the larger part of the 
ran-off of all of these coast streams must ordinarily come from the higher 
mountains, and illustrates the value of elevation in any shed for purposes 
of yielding run-off for reservoirs. 

The precipitation and catchment record kept at the Guyamaca dam 
from 1888 to 1896 shows that the drainage-basin of 11 square miles gave an 
average yield of 491 acre-feet of water per square mile, while the mean of 
the Sweetwater during the same period was 100 acre-feet per square mile^ 
or about one-fifth that of the Guyamaca. 

Since the great flood of January, 1895, the Sweetwater system to and 
including 1899 has not experienced a season of sufl^cient run-off to fill the 
reservoir, aod has endured practically four years of continuous drouth, as 
the entire catchment in these four seasons was 8,034 acre-feet, or 36^ of 
the reservoir capacity. As a result the reservoir was drained to the bottom 
early in 1899, and it became necessary for the company to develop and put 
in operation an entirely new and independent supply for the preservation 
of the orchards. Two independent gasoline-engine, centrifugal-pump 
pnmping-plants were established in the bed of the reservoir about 1^ 
miles above the dam, by which water was drawn from 35 small wells put 
down in the shallow sand and gravel-bed; the water there stored in the 
subterranean voids was thus made to yield a constant flow of about 
1 second-foot. This was conducted in a flume to the dam, and there 
admitted to the tower and the distributing system. The pumping was 
done with gasoline-engines, the lift being about 18 feet. In the valley 
below the dam three substantial pumping-s tat ions were installed, with 
steam-pumps, drawing from a large number of wells, bored at intervals of 
100 feet along the suction-pipe leading to the pump. In this manner the 
stored water in the sandy bed of the valley was made to produce 4 to 
5 second-feet additional. The season was successfully passed owing to the 
energy with which the supply was developed, the orchards were kept alive 
and thrifty, and no great suffering was experienced, although it seemed 

MA80NBY DAMS. 151 

inevitable afc the beginning of the irrigation season of 1899 that the orchards 
woald perish, or at least that there would be a total loss of frait, if not of 
the trees. Pumping operations extended from May to November 23, 1899, 
daring which time the total volume pumped was about 458,000,000 
gallons, or 1402 acre-feet. The area irrigated was approximately 3800 acres. 
Deducting from this total the amount of water used for domestic service, 
the mean depth actually applied to the orchards averaged 3.| inches. 
This small amount, supplemented by thorough cultivation, proved sufficient 
to save the orchards and keep them in healthy growth, which is an in- 
teresting demonstration of what can be done in an emergency. 

The cost of the pumping-plants and wells so quickly inaugurated as a 
substitute for the reservoir was about $27,000. The cost of pumping was 
about 6^ cents per 1000 gallons, which was covered by an increase in rates, 
to which the community cheerfully acceded as an emergency. The season 
of 1899-1900 having failed to give any run-off to the reservoir, all the 
pumping-plants in the reservoir-basin and below the dam were reinstalled, 
and an auxiliary plant, consisting of 40 wells, 2 inches diameter, 50 feet 
deep, pumped by a 22-H.P. gasoline-engine and 6-inch centrifugal pump, 
was added to the main plant at Linwood Grove, while at Bonita the same 
number of wells were sunk, and pumped by two 6-inch centrifugal pumps, 
placed in tandem and actuated by gasoline-engines. In this way it is 
hoped to tide over the third year of drouth. 

Sedimentation of Sweetwater Beiervoir. — Prior to the construction of 
the dam some apprehension was felt as to the probability of the speedy 
filling of the reservoir with sand brought down by the stream, which had 
been thought to be so large in volume as to destroy the usefulness of the 
reservoir in a short time. The writer made some observations on the load 
of sediment carried by the stream in flood during the constrnction of the 
dam, which led him to conclude that the reservoir might be filled with 
water a thousand times before becoming entirely filled with sediment.'*' 

Careful re-surveys of the reservoir made by Mr. H. N. Savage, chief 
engineer, since it became empty, demonstrate that the total filling has been 
about 900 acre-feet since the construction of the dam, or at the average 
rate of 75 acre-feet per annum. The total volume of water that has entered 
the reservoir in twelve years has been 180i,O6^ acre-feet. The measured 
solids deposited from this water have therefore averaged a trifie more than 
one-half of 1^. The deposit has been almost directly as the depth, being 
greatest at the dam, where the depth of silt of almost impalpable fineness 
is 2^ to 3 feet. The addition made to the reservoir capacity after the flood 
of 1895 was 4.6 times the accumulated sediment of twelve years, or, in other 
words, sufficient to offset the filling of half a century. 

* The Construcliou of the Sweetwater Dam. Trans. Am. Soc. Civil Eng., vol. xix. 
p. 214. 


Evaporation, — ^The percentage of water lost in storage-reeeryoirs by 
evaporation is the most serioas factor which the projectors of sach enter- 
prises have to anticipate. It is subject to wide variation dne to differences 
in mean depth, exposure, temperature, winds, and relative humidity, but 
it is always in operation, and subjects the reservoir to a constant loss, so 
great that it must be considered in all calculations of reservoir duty, as, in 
extreme cases, it may amount to 50^ per annum. 

Careful measurements of evaporation in a floating pan at Sweetwater 
dam shows the annual loss to be about 54 inches in depth. It is about 
2 inches during the month of January, and over 8 inches per month during 
July and August. This causes an annual loss of about 15^ of the stored 
water, and as a reservoir must always be held back for dry years, so that 
practically a reservoirful is at least a two-years' supply, the loss is really 
30^ of the total supply, leaving but 70^ of the reservoir capacity available 
for use, one-half of which only can be safely counted on each year. This 
reduces the available annual supply to about 8000 acre-feet. 

At the Guyamaca reservoir, on the adjacent watershed, the average 
loss reported during nine years prior to 1897 was 56f inches in depth per 
annum. This loss amounted to 25.5^ of the total water caught and stored 
during that time, which is nearly double that of the Sweetwater. This 
difference is due to greater surface exposure per unit of volume stored. 
The Sweetwater reservoir has an exposare of 39. 8 acres per 1000 acre-feet 
of capacity when full, while the Guyamaca has an exposnre of 84 acres per 
1000. This is an illustration of the advantage of great average depth in 
reservoirs, and an argument in favor of high dams for effective conservation 
of water. 

Conduits, — The main pipe leading from the dam is 36 inches in diameter 
for 1600 feet, thence 30 inches diameter for 28,200 feet to Chula Vista. 
It has a minimum capacity for delivery of 1260 miner's inches (25.2 
second-feet) to an elevation of 90 feet above sea-level, which is high enough 
to cover the larger part of the settlement. This pipe was found to be 
inadequate to the demands upon it, because in practice the maximum rate 
of consumption is about double the mean rate, and for the further reason 
that the higher levels could not be supplied and at the same time permit 
the maximum discharge to the lower levels. To remedy this lack of 
efiSciency a second conduit, 24 inches diameter, was built in 1895 on the 
north side of the valley of the Sweetwater. It is of riveted steel, 30,142 
feet in length, and cost $65,000. It has a minimum capacity of 450 
miner's inches (9 second-feet) and is used chiefly for high service. It con- 
nects at the dam with one of the 30-inch pipes laid through the tunnel. 
The distributing system of pipes, from 4 to 24 inches diameter, is over 65 
miles in length, and has cost over half a million dollars. 

Eemet Dam, California. — ^The most massive and imposing structure that 



Las thus far been erected iQ western American for irrigation-storage is the 
dam erected in the San Jacinto Moantains, in Bi^erside Goanty, California, 
at the ODtlet of Hemet Valley, the location of which with respect to the 
irrigated lands is shown in Fig. 71. The view in Fig. 72 is rather an 
imperfect representation of the appearance of the dam from below. Fig. 
T6 is an end view which shows the arched form of the dam. 

The dam is built of granite rabble, laid in Portland-cement concrete, 
and was designed to be carried to the ultimate height of 160 feet above the 
stream-bed. Its present height is 122.5 feet above base, or 135.5 feet above 

rjp.6S,f^./yy Tb.6S.Rje To.6S.f^.£C rn.6S./f.S£. 

Pig. 71.— Map showiiitg Location of Lakb Hemet, thb Main Conduit, and Isbi- 

GATED Lands. 

lowest fonndations. It is 100 feet in thickness at base, and has a batter of 
1 in 10 on the water-face, and 5 in 10 on back. Its present crest is 260 feet 
long, while the length on base is but 40 feet. The dam was bailt np with 
fall profile to the height of 110 feet above base, at which point the thick- 
ness is 30 feet. Here an offset of 18 feet was made, and the remaining wall 
is 12 feet at base, and 10 feet thick at top. A spillway notch 1 foot deep, 
50 feet long, was left in the center. Extreme floods may exceed the 
capacity of this spillway and pass over the entire length of the wall to the 
depth of several feet. This actaally occarred in Janaary, 1893, when the 
dam was 107 feet in height. The dam is arched np-stream with a radias 
of 225.4 feet on the line of its apper face at the 150-foot contonr, althongh 
it has a gravity section, with the lines of pressare inside the center third, 
as shown on section in Fig. 75. 

The site seemed to be more saitable for a masonry stractare than any 
other type benanse the canyon is extremely narrow, the fonndations excel- 
lent, and materials for constraction abandant. After dae consideration of 
all alternative possibilities the writer was directed to prepare plans saitable 
for the maximam height to which a dam coald be bailt to advantage at this 


site, and in the sammer of 1890 the plant was assembled and ezcavatioa 
began. The stripping to bed-rock occupied several months, with the aid 
of a cableway for conveying the waste to a damp beluw the dam. In thia 
operation a large hole was developed in the rock, 13 feet in depth, within 
the lines of the base of the dam. This hole was foand to be filled with 
gravel, firmly cemented in place so tightly that it might safely have been 
bailt upon had its limits been known. After the hole was cleaned oat a 
center trench was cut in the bed-rock np the sides, as a key or anchorage^ 
to receive the masonry. 

The cement and all tools had to be haaled up the mountain, a distance 
of 23 miles from the nearest railroad station, over a road whose maximum 
grade is 18^, making a total ascent of 3350 feet, and descending to the dam 
from the summit nearly 600 feet. The haaling was done at a cost of $1 
to 11.50 per barrel, and occupied a considerable time in delivering a suffi- 
cient quantity to make a beginning, and it was the 5th of January, 1891^ 
before the first stone was laid. 

The total amount of cement used was about 20,000 barrels, which cost 
delivered about $5 per barrel. 

Work was prosecuted without interruption until January 24, 1892, 
when severe weather and floods compelled a suspension of construction for 
four months, when the 45-foot level was reached. 

On resumption of work the following spring it was pushed to the 107- 
foot contour, when the workmen were again driven off by a storm and 
freshet on January 9, 1893, when the reservoir was filled so rapidly that 
many of the buildings and tools were submerged before they could be 
removed. The work remained at this stage until the fall of 1895, when 
the dam was completed to its present height and all machinery and tools 
were brought down the mountain. At its present height the dam contains 
31,105 cubic yards of masonry. 

The concrete used to embed the blocks of stone was mixed in the pro- 
portion of 1 of cement, 3 of sand, and 6 of broken stone, crushed to pass 
through a 2^-inch ring. Mortar was only used in laying the facing-stones 
and pointing the joints on the exterior faces. Both concrete and mortar 
were mixed by a cubical iron mixer, one of a number that had done service 
on the San Mateo dam in northern California. The sand used was clean 
and sharp, and was constantly brought to the dam by the small living stream 
fiowing from the mountains, the sand being rolled along its bed. It was 
accumulated in a little resenroir formed by a temporary log dam, and con- 
veyed to the mixing-platform by an endless double-wire-rope carrier, fitted 
with triangular buckets, placed at intervals of 20 feet. By this means the 
sand was hoisted 125 feet and carried horizontally 400 feet to the mixing- 
platform, where it was stored in a bin. This device was very simple, inex- 
pensive, and quit^ effective, and the sand was always washed clean. Fig. 

MA80SB7 DAM8. 



76 shows a view of the plant for crashing the stone and mixing the 

concrete. A portion of the sand- conveyor is also visible in the photograph, 

as well as one of the engines naed on the cableways, and the cars for the 

Profile Masonry Dam « 


Sect/Of} of Ape a/tt/Ha/fa 

Fio. 75.— Ukuet Dau, KivEiiHiDE (Juuhtt, Caliporhia. 
delivery of concrete to the dam. These latter ran along a tramway, laid 
on a trestle bnilt from the mixing-platform along the face of the vertical 
cliS, some 300 feet, to the dam at the 80-foot level. When the dam reached 
this level an elevator was bailt to a higher line of trestle. 


The stone was all qnarried witbin 400 feet of the dam, on both sides of 
the canyoD, both abore and below the darn. It was hoisted and coDvejed 
to the wall by two cablewajs, each abont 800 feet long and 1} inches id 
diameter. The cables crossed the dam nearly at right angles with ihe 
chord of the arch, bat diverging from each other, and were anchored to 
coQTenieat trees on either side of the gorge. Their position was seldom 
changed, except to lift them higher up into the tree-tops, aud to erect " A " 
frames on top of the masonry to support the cables, when the wall bad 
reached such a height as to r^qnire it. Loads of 10 tons could be hoisted 

Fio. 76. — Hewet Dam Cohbtrhction Pi.AirF. 

and handled with ease, and with the aid of two derricks, one at each end of 
the dam, the rock bronght by the cables was placed where required. The 
loads were readily transferred from the cableway to the derricks while in 
the air. The trolley which traveled on the cableway, and the devices for 
sustaining the hoisting-line as the load moved back and forth, were devised 
on the ground and operated satisfactorily. 

The derricks were actnated by water-power obtained from a 36-inch 
Pelton wheel located below the dam and propelled, nnder a head of 76 feet, 
by abont 80 miner's inches of water, bronght from the stream by a flnme 
1.5 miles long to the edge of the cliff at the mixing-platform, and thence 
in a 13-inch riveted steel pressare-pipe. The pipe passed through the line 
of the dam and was embedded in the masonry. Subaeqnently it was cat 


off at the upper face of the dam and was made available as the lowest outlet 
of the resenroir. Two other outlets were provided, consisting of 22-inch 
lap-welded steel pipes, placed at the 45-foot and 75-foot levels, near the left 
wall of the canyon. These pipes were provided with cast-iron elbows 
tnrning upward and flaring to 30 inches diameter, just inside the line of 
the dam. They are closed by semi-spherical cast-iron covers, which are 
raised and lowered by wire ropes passing over a pulley and windlass that are 
provided for each, and stand on an overhanging frame bolted to the top of 
the masonry. These covers are ordinarily removed and replaced by cylin- 
drical flsh-screens that stand on the top of the elbows, and the main control 
is had by gate-valves set on each pipe at the lower line of the dam. When 
these valves are open the water spouts freely into the air and falls in a spray 
upon the rock below. This water is collected in a pool a short distance 
from the dam, and passes over a weir for measurement, before beginning 
its 5-mile plunge down the canyon, to the final point of diversion into the 
main flume. 

When construction began, the reservoir-site was well covered with pine 
forest, and, as it was desirable to clear the flowage tract, the trees were cut 
and sawed into lumber. Over one million feet B.M. of this lumber was 
used for buildings, flames, and staging about the dam, and half a million 
more was hauled to the valley for flumes and trestles. Much of the fire- 
wood cat from the tree-tops was also hauled down the mountain by the 
retarning cement teams. The main conduit is partly built of this mountain 
pine, and, although it is knotty and inferior lamber for general purposes, 
the flume made of it did good service for eix or eight years before it was 
recently replaced with California redwood, which is much more durable. 
The conduit is 3.24 miles in length from the pick-up weir, just above the 
janction of Soath Fork and Strawberry Fork, to the mouth of the main 
canyon, where it connects with a 22-inch riveted iron pipe, 2 miles long. 
From the end of this pipe an open ditch, lined with masonry 8 to 10 inches 
thick, and plastered with cement mortar, conveys the Water 5 miles to a 
20-acre distributing-reservoir, located near the highest corner of the irri- 
gated lands. This reservoir has a capacity of about 90 acre-feet, and from 
it the water is distributed by some 30 miles of pipe, flumes, and lined 
ditches. The slope of the land is 40 feet per mile from east to west, 
requiring small conduits for distribution. The main canyon flume was 
built of 1^-inch lumber, and is 38 inches wide, 18 inches deep, and has a 
grade of about 140 feet per mile. It was calked and battened, smeared 
with asphalt inside, and whitewashed on the exterior with lime. The ditch- 
lining consists of granite cobbles of 10 inches maximum diameter, laid in 
equal parts of lime and cement mortar. It is 2.75 feet wide on bottom, 
7 feet at top, 2.75 feet deep, and has a capacity of 60 second-feet or 3000 


The dam of the distribating-reBerroir is of earth, 300 feet long, 14 feet 
high, and 8 feet wide on top. The reservoir is usaally filled within a foot 
of the top of the dam. In constr action a trench was excavated 9 feet deep 
under the center line, in the center of which a tighfc board fence was built, 
reaching to the top of the dam, to prevent the harrowing of ground- 
sqairrels and gophers^ a fanction which it effectually performs. The trench 
was refilled with paddled soil each side of the fence, and the paddle brought 
to the top of the dam. The area irrigated by the system in 1896 was 1092 
acres, and is increasing each year as the tracts are sold to settlers. 

This area was in 72 separate tracts, of which the average size is 10 to 
20 acres. The rates charged for water are t;2 per acre annually, with an 
additional charge daring the nominal '' non-irrigating season" (November 
15 to April 15) of $1 per month for each tract for domestic service. In 
the town of Hemet, which is supplied by the same system, there were, in 
1896, 55 taps, paying a uniform domestic rate of 11.50 per month. Water- 
power is used in the town to drive an electric dynamo for lighting the hotel 
and some of the buildings, the waste water flowing to a small reservoir. 

The apportionment of water by the water-right contracts given with 
the deeds to the land is at the rate of *' one-eighth of 1 miner's inch of 
perpetual flow from April 15 to November 15 of each year for each acre." 
This is equivalent to 46,224 cubic feet per acre per annum, or a mean depth 
of 12f inches over the land. The water-rate of t2 per acre woald thus be 
equal to 4.3 cents per 1000 cabic feet, or 0.57 cent per 1000 gallons. 

The altitude of Hemet Valley where the dam is located is approximately 
4300 feet. The watershed area, as determined from the topographic map 
of the United States Qeological Survey, is 69.5 square miles, the extreme 
elevation of which is about 9000 feet This point is Tahqnitz Peak, a spur 
of Mt. San Jacinto. The total drainage-area of the San Jacinto Biver 
above the mouth of the canyon is 141.8 square miles. The reservoir there- 
fore receives the run-off from nearly one-half the entire drainage-basin of 
the river. The average yield of the shed has not been accurately deter- 
mined, although it has been insufficient to fill the reservoir in any one 
season since 1895. The irrigation season of 1899 began with but 1000 
acre-feet in the reservoir (gage 73 feet). 

The present capacity of the reservoir is 10,500 acre-feet, but the addi- 
tion of 27^ feet to the height of the dam will increase it 2^ times. The 
cost of the dam and irrigation-works has never been made public. The 
area of the tract depending upon the reservoir for irrigation is about 7000 
acres, of which not more than half have been irrigated. 

The Bear Valley Dam, California. — Probably the most widely known 
irrigation system in California is that of the Bear Valley Irrigation Com- 
pany of Badlands, California, chiefly by reason of the remarkably slender 
proportions of the Bear Valley dam, which has been to the engineering 


fraternity the '^ eighth wonder of the world/' and has no parallel on the 
globe. The dam has no stability to resist water-pressure except that due 
to its arched form, and it has been expected to yield at any time, although 
it has successfully withstood the pressure against it for fifteen years, and is 
apparently as stable as it ever was. The probabilities are that nothing but 
an extraordinary flood or earthquake, or a combination of unusual move- 
ments, will ever accomplish its destruction. Such vast interests are now 
dependent upon the water stored by the dam that its failure would be a 
public calamity, greatly to be deplored. The settlements of Redl&nds, 
Grafton, and Highlands, which are among the choicest of the orange- 
growing regions of southern California, and the irrigation districts of 
Alessandro and Perris, are the outgrowth of this water-storage, although 
the Perris district receives but a small portion of its supply from this 
source. Prior to the construction of the dam in 1883-84, the natural 
streams entering the San Bernardino Valley had been entirely appropriated 
and used in irrigation, and had apparently reached the limit of their 
irrigable duty. No storage-reservoirs were then in service, and the creation 
of the Bear Valley reservoir for conserving the flood- waters of the Santa 
Ana Eiver has more than doubled the area of land irrigated previous to its 
construction in the territory covered by its water, and has increased the 
valuation of property in far greater ratio. The useful function of the 
storage-reservoir was never more fully exemplified than in this case. The 
Bear Valley dam was designed and built by F. E. Brown, C.E., a graduate 
of Yale Scientific School. The construction of the dam was a bold and 
difficult undertaking, as it was the pioneer enterprise of California for 
irrigation-storage, and the site is in a remote locality, to which the cement, 
tools, and supplies had to be hauled over a rough mountain-range from 
San Bernardino, descending on the opposite side to the Mojave Desert 
and again climbing the mountain to Bear Valley, a total distance of 70 
miles. The cost of hauling cement was 110 per barrel, and its total cost 
delivered was $14 to $15 per barrel. Under such conditions, and with a 
scarcity of funds for what was considered a questionable experiment, it is 
not surprising that economy of masonry was practiced to such an extent 
that it is quite without a parallel for boldness of design. The d&m is 
curved up-stream with a radius of 335 feet, and is 64 feet high from base 
to crest. The length on top is about 300 feet, and the thickness but 2.5 
to 3 feet on top, and 8.5 feet at a point 48 feet below the crest, where it 
rests on a base of masonry that is 13 feet wide, making an offset of about 
2 feet on each side at the center; but as the base was built with a curve of 
shorter radius than the upper 48 feet of the dam, the offset is not uniform, 
but tapers to nothing on the waterside at the ends of the base, and is fully 
4 feet wide on the back. The lowest foundation of the base is 20 feet wide, 
as shown in Figs. 77 and 78. The entire dam contains about 3400 cubic 

Fio. T6((. — Lake Hemet (CaI: ) Mabohry Dam. 



yards of tnaaonrj, in which were ased about 1600 barrels of cement:. It is 
reported to have cost t75,000, or over #23 per cnbic yard, of which the 
cement alone cost bat 17.50 for each cnbic yard of masoiiry laid. That the 
plant and labor could have cost bo much as tl4.dO per cubic yard, which is 
severnl times the ordinary cost of snch work, mast, if true, have been 
largely attributable to the lack ot adequate machinery, as well as extrava- 
gant management. The masonry is a rongh, uncnt, granite ashlar, with a 

Pio. 7?.— CROaBSBCTiON OF Bear Vallkt Dam. 

Fio. 78.— Pr AN AND Elevation of Bead Valixy Dam. 

hearting of rough rubble, all laid in cement mortar and gravel. At the 
beginning an earth dam was erected, 2^ milea above, 6 feet in height, to 
retain the summer flow. Ae the masonry rose water was let down to the 
main dam, forming a pond which floated timber rafia on which stone was 
transported to the site, and from which construction was carried on. Hand- 
derricks were carried on these rafts. 

Tl)e work was evidently done slowly and with great care, as it has leaked 
bnt little beyond the usual sweating, which has left its marks in an efflores- 
cence or deposit of lime, brought out of the mortar by the moisture oozing 
through. This occurred during the iirst few years after completion and 


has almost entirely ceased. When iDspeeted by the writer in Angast, 1896, 
the water stood within 10 feet of the top of the dam with little or no visible 
leakage below. 

The south end of the dam abnts against a projecting ledge of granite, 
standing boldly oat from the side of the canyon 100 feet or more beyond 
the general line of the side slopes, illastrated in the photograph. Fig. 79. 
07er the top of this ledge, as far from the dam as it could be placed, a 
spillway, 20 feet wide, was excavated to a depth of 8.5 feet below the level 
of the extreme top of the dam (Fig. 80). 

The extreme capacity of this spillway does not exceed 1700 second-feet, 
which is dangerously small. 

The great Sweetwater flood of 1895 gave a maximum discharge of nearly 
100 second-feet per square mile of watershed. A freshet of proportional 
volume from the Bear Valley shed would give a discharge of about 5600 
second-feet, or more than three times the spillway capacity. Occurring at 
a time when the reservoir were full, such a flood would overtop the dam by 
a depth of 2 to 3 feet. The result might be disastrous. 

The spillway was for a time closed with sand-bags to hold the lake to a 
higher level, but this device was substituted by movable flashboards, 
arranged in four bays, separated by suitable framework. 

The only outlet or means of control of the reservoir is an iron gate made 
to slide on brass bearings, and closing a rectangular opening, 20 by 24 
inches, leading to a culvert cut in the bed-rock. The culvert trench was 
made 2 feet wide and 3 feet high, fiat on bottom and arched over the top 
with concrete. The dam was built over it, and the culvert simply passed 
through or under the wall. The gate is operated by a screw-stem that 
passes up through a 6-inch pipe, standing vertically in the water next to 
the dam, and reaching up to a wooden platform at the coping-line. The 
gate-stem, hand-wheel, and mouth of outlet culvert are shown in the illus- 
tration. The maximum discharge capacity of the gate when wide open 
with full reservoir is about 167 second-feet, which is much more than is 
ever required to be drawn. The capacity with reservoir practically empty 
is over 80 second-feet. 

The top of the dam is not finished to a true level line, as the coping- 
stones have been omitted over about one-half the length, and this portion is 
2 to 3 feet lower than the finished crest. It requires considerable nerve to 
walk over the top of the dam, because it has no hand-rail or parapet and is 
so narrow that few visitors care to attempt the feat. Water has stood for a 
considerable time within a few inches of overfiowing, although it has never 
actually passed over the top, as the spillway has thus far been capable of 
carrying the surplus flood-water. The maximum volume stored in the 
reservoir, thus far, has been somewhat in excess of 40,000 acre-feet, and 

Fio. T9.— Bbaii Vallet Dam, i.otiKiNO Souri 

MA80NRT DAMS. 173 

in seasoiis of excessive precipitation the ran-off has exceeded the reservoir 

Iq order to be able to imponud the entire ran-off from the watershed, 
or the greater portion of it, the company at one time contemplated the 
erection of a higher dam, to be bailt about 200 feet down-stream from the 
present dam, and impound water to the 75-foot contour of the reservoir, or 
11 feet higher than the crest of the existing structure, at which level the 
capacity of the basin is 80»000 acre-feot, flooding a surface area of 3060 
acres to a mean depth of 25.3 feet. It was regarded as impracticable to 
add another foot to the height of the present dam, and no engineer cared 
to risk the responsibility of excavating at the toe of the wall for such an 
addition to it as would enable it to be raised to the desired height; hence 
it was deemed best to go a safe distance below to avoid jarring or disturb- 
ing the fragile wall, and there begin an entirely independent structure. 
Tiie new dam was designed as a rock-fill, and was to be 80 feet in height 
above the base of the present dam, but was never finished beyond the 
foundations, which were laid in a substantial manner in 1893 (Fig. 81). 
It is a matter of regret that the second dam was not completed, as its com- 
pletion was recognize! as affording a rare opportunity for studying the arch 
action upon the present masonry wall. At the time it was begun a com- 
mittee was appointed by the American Society of Civil Engineers to 
examine and measure the movement in the masonry incident to the loading 
and unloading of the arch. This could be quickly accomplished by empty- 
ing and refilling the pond between the two dams. If taken at the right 
time, the effect of a flood pouring over the crest of the thin masonry wall 
could have been observed, and much nseful knowledge obtained on the 
subject of the strains in arched dams of which so little is now known. 

The watershed tributary to the Bear Valley reservoir, as determined 
from the best available maps, is approximately 56 square miles, the maxi- 
mum elevation of which is about 7700 feet, or 1500 feet higher than the 
valley. On the north and east the shed borders on the desert, and the pre- 
cipitation shades off to a considerably less amount than is recorded at the 

The record of rain and melted snow at the dam from 1883 to 1893, the 
season beginning in each year on September Ist, is as follows: 

Inches. Inches. 

1883-84 94.60 1888-89 46.03 

1884-85 28.06 1890-91 78.40 

1885-86 65.51 1891-92 38.00 

1886-87 24.00 1892-93 44.32 

1887-88 62.30 1894-95 50.00 

Mean for 12 years 53.70 


The dry years which have occarred since 1895 mnsfc andoabtedly reduce 
this mean very considerably, aUhoagh the record has not been made pablic. 
In 1891 the ran-off from the watershed was compnted by Wm. Ham. Hall 
from the records of catchment, as follows, beginning with the completion 
of the dam : 

9-00. «--f-, season. f-^^,^ 

1883-84 236,000 1887-88 132,400 

1884-85 21,600 1888-89 70,400 

1885-86 142,400 1889-90 211,600 

1886-87 8,000 1890-91 186,800 

Mean 126,150 

This estimate is so large as to be decidedly qaestionable. Mr. J. B. 
Lippincott, Hydrographer U. S. Geological Survey,* estimates, by compari- 
son of observations in other parts of the State, that the probable maximum 
run-off of the shed is about 100,000 acre-feet, and the mean about 28,500. 
The minimum was doubtless reached in 1895-99. The irrigation season of 
1899 began with but 1560 acre-feet in the reservoir, a small portion of 
which was held o7er from the previous year. This was entirely exhausted 
early in the season, and an attempt was made to maintain the supply by 
pumping from shallow wells in the bed of the reservoir, although with 
indifferent success. Four to six acre-feet per day were obtained for a time, 
but it was largely dissipated by evaporation in passing down the canyon. 

The loss to be anticipated, from this reservoir by evaporation is a sub- 
ject of much interest. It is at an altitude of 6200 feet, and well sheltered 
from winds by surrounding mountains, favoring minimum loss. On the 
other hand the water is shallow and spread out over a large area. Observa- 
tions made at the gate-house of the Arrowhead Reservoir Company in Little 
Bear Valley, in the same mountain-range, but at lower elevation (5160 feet 
above sea-level), indicate that the evaporation from water-surface is about 
36 inches per annum in that locality, of which about 90^ occurs in the 
eight months from March to November, inclusive. This rate of loss applied 
to Bear Valley reservoir when full would indicate a probable loss of over 
20^ per annum if &o water were drawn out, or about 14^ per annum if a 
uniform draft of 2500 acre-feet per month were made during the period 
from March to November, inclusive. 

The general form of the reservoir is shown in Fig. 82. 

La Grange Dam, California. — There is something quite unusual in a 
masonry dam 125 feet high which is erected for the sole purpose of divert- 
ing water from a stream for irrigation purposes, and this is the character of 
structure that was built on the Tuolumne River, 1^ miles above the town 

* Nineteenth Annual Report for 1897, U. S. Geol. Bur., Part IV., p. 585. 



of La Orange, California, in 1891-94, by the Turlock and Modesto irriga- 
tion districts jointly. The Tuolumne River, as it leaves the mountains, on 
its way across the San Joaquin Valley, is cut down so deeply below the 
geneial level of the plain as to require a high dam to raise the water suffi- 
ciently to get it out on the irrigable lands. The dam is located at the 
mouth of a narrow box canyon and is in no sense designed or used for 
storage. It is 125 feet high on the up-stream face, 129 feet on the down- 
stream side, 90 feet in thickness at bottom, 24 feet at crest, and but 310 
feet long on top. The wall is built as the segment of a circle of 300 feet 
radius, the arch being opposed to the direction of the water-pressure, 
although its profile is of purely gravity type, in which the lines of pressure 
are well within the middle third. On the water-face the dam is vertical for 
70 feet below the top, and thence to the foundation has a batter of 1 in 20. 
The edges of the crest are rounded off on a radius of 3 feet on upper side, 
and 17.5 feet on lower side, leaving 6 feet of the crest level. At 6 feet 
below the crest the dam is 24.13 feet thick; at 69 feet below it is 52 feet 
thick; at 89 feet it is 66.25 feet; and at 97 feet, the top of the foundation 
masonry, it is 84 feet thick. The extreme bottom width at the highest 
point of the dam is 90 feet. The lower face has a batter of J to 1, from 70 
feet below the crest, where a compound curve of 63 and 23 feet radii 
commences, which carries the face to its intersection with the battered face 
of the foundation masonry about 3 feet above low water. From this point 
the foundation batter is 1 in 7, to the bottom, about 32 feet in the 
deepest place. These dimensions give practically an ogee form to the 
down-stream face, which permits the water to follow the masonry without 
leaving its face in its descent, provided the depth be not more than 4 to 5 
feet, and gives it a horizontal direction at the bottom. The curvature of 
the dam and the fact that the canyon is but 80 feet wide at the base of the 
dam, or top of foundations, so concentrate the stream that some erosion 
may be anticipated at the base, although nothing serious in that line has 
been reported. 

The dam contains 39,500 cubic yards of masonry and cost $550, 0C9. 
It is built throughout of rough, uncoursed rubble masonry, laid in Portland- 
cement concrete, in practically the same manner as that described in the 
construction of the Hemet dam. The work was done by contract, at $10.39 
per cubic yard, including the excavation for foundations, but not including 
cement, which was furnished by the districts. The cement cost $4.50 per 
barrel delivered, and 31,500 barrels were used in the work. 

It is believed to be the highest overflow dam in the United States, if not 
in the world. The volume of water passing over it may in extreme floods 
amount to 100,000 second-feet. The maximum flood that has yet gone 
over the dam was about 46,000 second-feet in volume, the deptii on crest 
being 12 feet. 

FiQ. 82a.— Pi-AK t>¥ La GBANor. Dam, Caupornu. 
^^ _^ 

Fio, 824.— PKOFrLB OF La Uhakoe Dau, Caupobhia. 


Daring conetrnction the low-water diacharge was carried past the work 
in a flame the first year, and snbsequently through two culverts, one at low- 
water level, and a second 10 feet higher. These were 4 feet wide, 6 feet 

The Modesto Canal takes water throngb an open cut from the dam, on 
the right bank, and haa a capacity of 750 second-feet. The Tnrlock Canal 
reaches the reservoir above the dam by meane of a tnnnel 560 feet long, 12 
feet wide, 11 feet high, with regalating-gate at the head. 

PiB. 88.— Uppek Face oy La Obanoe Dam, 

In construction of the dam three lines of cableway were used, spanning 
the canyon, for hauling the materials. 

The excessive cost of the work was doubtless due to the uncertainty as 
to the value of the bonds of the irrigation districts, which created a temerity 
among contractors, and there were few bidders. The contractor was 
obliged to buy the bonds at not less than 90^ of their face value, and dispose 
of tliem at a figure from which he could obtain a profit on his work. 
Under ordinary conditions of prompt payments in cash the construction 
shonld have been done for one-half tlie actual cost. 

The dam was designed by Luther Wagoner, C.E., who resigned 


shortly after work began, and coustmction was completed under chaise of 
E. H. Barton, engineer for the Turlock district, and I£. S, Crowe, repre- 
aenting the Modesto district. 

The elevation of the crest of the dam is 299.3 feet above sea-level, and 
the canal grade ie 8.3 feet lower. 

The Turlock irrigation district embraces 176,210 acres, and the canal 
supplying it has a reported capacity of 1500 second -feet. The main canal 
ie 18 miles long, feeding five laterals of an aggregate length of 80 miles. 

Fig. 84.— Lower Facb of La Quakob dak. 

The Modesto district covers 81,500 acres, with a main canal 33.76 miles 
long before reaching the district, having a capacity of 640 second-feet. 
Tho entire irrigation system when fully completed will be the largest and 
most comprehensive one in California, and the dam upon which its success 
depends haa been wisely constructed of such dimensions as to be of unques- 
tionable stability. Figs. 83 and 84 give two views of the stmcture. 

Folsom Dam, California. — There are many features of the Folsom dam, 
on the American River, California, which give it special interest to engi- 
neers and all others who have seen it, one of which is that it was bnilt by 
the State of California entirely with convict labor, incidentally to give 
employment to the inmates of one of the State prisons, but primarily to 


develop water-power for use in various industries about the prison and for 
transmission to other localities. A further purpose is served by the dam in 
the diversion of water from the American Eiver out upon the plains of the 
Sacramento Valley for irrigation. The plan, profile, and section of the 
dam are shown in Fig. 90, and a photograph taken by a convict during 
construction is given in Fig. 91. 

The dam is of the same general character as the La Grange dam, 
serving no purpose of storage, but designed solely for the diversion of the 
stream and so constructed as to permit flood-water to pass freely over 
its crest. 

It is located at the top of a natural fall in the bed-rock of the stream, 
its height at tlie up-stream toe being 69.5 feet, while at the down-scream 
footing the height is 98 fest to the crest-line. . The top thickness is 24 
feet; base 87 feat. A movable shutter, 180 feet long, is placed in the center 
of the dam for raising the normal wnter-level at low stages. This shutter 
is placed in a tlopression, C feet in depth, below the general level of the dam, 
and is lowered during floods to allow the passage of extreme freshets over 
tlie dam. At low water tlie shutter is raised to a nearly vertical position 
by means of liydraulic jacks, as sliown in Fig. 92, which are operated from 
the prison power-house. The entire crest length of the dam is 650 feet, 
including the curved approach to the canal head-gates. 

The main dam is straight in plan. The construction of the dam was 
begun in 1886 and completed in 1891. It contains 48,r)90 cubic yards of 
masonry in the dam proper, while the retaining-wall of the canal has 
27,000 cubic yards and the power-house 13,700 cubic yards of granite 
masonry, all laid in Portland-cement mortar. The dam is a very massive 
and substantial piece of masonry, composed of rough granite ashlar in 
large blocks of 10 tons or more in weight. The quarry, which deter- 
mined the location of the State prison, affords an unlimited quantity of excel- 
lent granite which has a fine cleavage and is readily quarried into blocks of 
any desired size. The excavation of the canal along the granite cliff gave all 
the material needed for the dam. "JMie stone was delivered to the dam bv a 
cableway of unusual construction, in that two cables were used side by side 
like a suspended rail way- track, and the trolley was a four-wheeled carriage 
from which the loads were hoisted and suspended. There are many disad- 
vantages to this form of cableway, and no special features to recommend it 
as preferable to the single cable. The latter admits of dragging roi-ks from 
either side of the line of the cable for a considerable distance, an operation 
which would tend to derail the trolley of a double cableway. 

The canal taken from the left side of the dam passes through the 
prison grounds and thence to the town of Folsom, one and one-half miles 
below, where the main power-drop of 85 feet is utilized for generation of 
power, which is transmitted electrically to Sacramento, 22 miles distant. 



Pio. 80-— La Gr.' 

fto. 87.— La Giianub Dam, California. 

Pro, 88. — La Qranok Dam, Caufohnia, i 

Fio. 89.— Map showino Location of Folsom Dau and the Main Canal. 



Fxa. 90.~PiiAK, Cross-section, and Elevation of Weib and Headworks of 

FoLSOM Canal. 



In paasing the prison power-house a drop of 7.5 feet is ntilized by six 
8?-iDch Leflel turbines of the double improved type, aud about 800 H.P. 
are developed at the maiimum. The canal is 8 feet in depth throughout, 
the vidth belov the prison power-houso being 30 feet on bottom, 4U feet 
on top. Above the power-house the width is 10 feet greater. The grade 
is 1 : 3000, and the capacity of the canal about 1000 second-feet. 


Fio. 93.— Etdraulic Jacks for raibino Brctter on FoLaoK Dam. 

The 8aa Kateo Dam, California. — Doubtless the most enormous mass of 
masonry of any sort in the West, if not in the entire United States, is the 
great concrete dam erected on San Mateo Creek, 6 miles above the vilUge 
of San Mateo, California, by the Spring Valley Water-works of San Fran- 
cisco, to impound water for the supply of that city. The dam ranks 
among the highest and most costly of the world, and was erected in 1887 
and 1S88. 

It was projected to reach to a height of 170 feet, at which the top width 
ms to be 26 feet and base width 176 feet, but construction was suspended 
at the height of 146 feet, or 34 feet below the ultimate height. When 
finished the top length will be 680 feet. It has a uniform batter of 4 to 1 
on the np-stream face, while the lower slope, beginning with a batter of 2^ 
on 1 near the top, curves with a radius of 258 feet to near the bottom, 
where the batter is 1 to 1. The dam is arched up-stream with a radius of 
637 feet. 

It is built throughout with concrete, made of broken stone, beach sand, 
and Portland cement. This material was chosen because of the difhculty of 
secaring rock in the vicinity suitable for rubble masonry. The stone was 
qnarried in the immediate vicinity, and occurred in small irregular nodules. 


frequently so coated with clay and serpentine as to require it to be thoroughly 
washed before it was fit for use. After crushing, it was passed through 
revolving cylindrical tumblers, where a constant stream of water was main- 
tained to carry off the mud and tailings, which passed off through a flume 
and dropped to the stream-channel, where the deposit from these washings 
covered several acres to a considerable depth. The proportion of waste was 
large. The sand used in the concrete was obtained from the sand-dunes of 
Korth Beach, San Francisco, where it was loaded on cars, hauled one mile, 
and dumped into barges, then towed 25 miles up the bay to a landing oppo- 
site San Mateo, and thence hauled 6 miles by wagon to the dam. All the 
materials were thus unusually expensive. 

The concrete was mixed in a battery of 6 cubical iron mixing-machines 
revolved by steam-power. It was delivered to the work by a double-track 
tramway on a high trestle carried part way across the canyon at the level of 
the top of the dam on the lower side, as shown in Fig. 94. The cars on this 
tramway were pushed by hand and dumped into hoppers let into the floor 
between the rails, leading to vertical pipes, 16 inches in diameter, which 
extended down to platforms that were placed from time to time at a level 
with the top of the work as as it progressed. The concrete dropped down 
these pipes, striking on steel plates, from which it was shoveled into wheel- 
barrows and trundled to the place of use. The height of this drop was 
sometimes as great as 120 feet, but no injury resulted to the concrete, or to 
the men shoveling it as it fell. The concrete was mixed in the proportions 
of 1 part cement to 2 parts sand, 6^ parts broken stone, and f part water 
by measure. It was moulded in cyclopean blocks of 200 to 300 cubic yards 
each, with numerous offsets ingeniously dovetailing the blocks together, and 
every possible precaution was taken in the joining of the successive portions 
to secure an absolute bond. The surfaces of the blocks after the forms were 
removed were roughened with picks, swept and washed clean, and grouted 
with pure cement before concrete was placed against them. The result has 
been very satisfactory ; the dam is almost absolutely water-tight, although 
some moisture does find its way through and appears in spots on the lower 
face. No settlement or expansion cracks are visible, and the work has the 
appearance of being absolutely homogeneous. Figs. 96 and 97 show the 
general method of foiming the blocks and preparing them to receive fresh 
concrete, and Fig. 98 is a general view of the dam taken at the time of the 
visit of the American Society of Civil Engineers in Annual Convention, 
July, 1896. Plans and sections of this dam are shown in Fig. 99. At the 
170-foot level the reservoir will have a capacity of 29,000,000,000 gallons, 
or 89,000 acre-feet. The present capacity is approximately 20,000,000,000 

The entire volume of the dam is approximately 139,000 cubic yards. 

When the dam is extended to its ultimate height it will be necessary to 





cmsTAL sf*ntNes resekvoib 




„„.<. l> 

Dam *m> JIai- ok C'KvttTAl. hl'UlMis Ulci^J.u\ciii( 

MA80NBT DAMS. 208 

dose a gap in the ridge a short distance north with a wall about 25 feet 
high. The outlet to the dam is a tunnel 390 feet long, driven through the 
hill on the north side of the channel, through which a 54-inch riveted iron 
pipe is laid. The tunnel is 7^ feet wide inside the lining, and of the same 
height, and is lined with four courses of brick, 21 inches thick. 

The tunnel is intersected by a brick-lined shaft, 14 feet clear diameter, 
placed just inside the dam in the reservoir. Inside this shaft is a stand-pipe 
connecting with the main outlet-pipe. Three branch tunnels, carrying large 
pipes, open out from the reservoir to this stand-pipe, each pipe being con- 
trolled by gate-valves that are placed in the main shaft. This is an admir- 
able form of outlet, as all the pipes from the shaft are accessible to inspection 
and repair. The ends of the tunnels under water have plain cover-valves 
over elbows, and are provided with fish-screens that are put into position 
from floating barges. A main pipe, 44 inches in diameter, leads from the 
dam to San Francisco. The present crest of the dam is 281 feet above tide- 

When the reservoir is filled it submerges the old Crystal Springs reser- 
voir and dam, the latter being an earth structure which did service for many 
years until superseded by the new dam. A smaller reservoir, that formerly 
supplied the town of San Mateo, was also obliterated from view, and the 
water at highest level will extend up the valley of the north arm of the 
creek nearly to the toe of the San Andreas dam. 

The old Crystal Springs reservoir had a tributary watershed of 14 square 
miles, which yielded a mean annual run-off of 319 acre-feet per square mile 
during the eight years from 1878 to 1886. The mean rainfall during that 
period was 34.95 inches. This run-off is equivalent to a mean of 14.4^ of 
tlie mean rainfall, the maximum having been 34^ and the minimum 0.5^. 

The Pilarcitos and San Andreas watersheds, whose catchment is retained 
by earthen dams, receive a much higher precipitation, especially the former, 
which is more directly exposed to the saturated wind-currents from the 
ocean. The average precipitation over all the Spring Valley Water Co.'s 
sheds, during the seven yeara from 1868 to 1875, was 43.5 inches, from 
which the mean run-off was 35.5^, including loss by evaporation. These 
watersheds are partially wooded, undulating pasture-lands, uncultivated, 
covered with deep soil, and clothed with native grasses that spring up annu- 
ally from seed and have little permanent sod. The results of the measured 
catchment from these areas indicates that, in geneml terms, on watersheds 
of this character from 20 to 35 inches of rainfall are annually taken into the 
soil and absorbed in plant-growth and evaporation. 

The Xetoell Curve of Run-off, — On Fig. 100 is shown a diagram, called 
the ** Newell Curve," from its originator, Mr. F. H. Newell, C.E., Chief 
Hydrographer, U. S. Geological Survey, which expresses the general relation 
between mean annual rainfall and mean run-off, as determined from the 



measurements of a large number of streams, compared with the best avail- 
able data as to the probable mean precipitation on the watersheds of those 
streams. This is a convenient diagram for general deductions, as it shows 
at a glance the increasing percentage of run-off to be expected from heavy 
rains, and the very small amount to be derived from low rainfall. Upon 
this diagram the author has platted a number of actual measurements of 
run-off on certain California watei-sheds and some others, which are mostly 
indicative of lower percentage of run-off than the lines of the curve. The 
difficulty in applying such a diagram to estimates of probable run-off is in 
determining the mean rainfall applicable to any given shed, and in the 
variability of run-off in different seasons, due to the uneven manner in 
which storms appear. Bains gently and evenly distributed will give a much 
smaller stream-flow than the same amount would yield if it came in a succes- 
sion of violent storms, quickly following one another. 

Pacoima Submerged Dam, California.— One of the most novel and inter- 
esting masonry dams erected for impounding water in California, where so 
many novelties and experimental works have been carried out, is a slender 
little reservoir wall built across Pacoima Creek, in the San Fernando Valley, 
20 miles north of Los Angeles, for the purpose of forming an underground 
reservoir, whose storage capacity consists solely of the voids in the gravel- 
bed filling the valley of the stream. 

The creek drains a watershed whose area is 30.5 square miles above the 
point where it issues from the mountains. Here it flows over exposed bed- 
rock, and the normal summer flow, which diminishes gradually from about 
100 to less than 10 miner's inches, is entirely diverted by a pipe-line and 
used below for irrigation. The dam in question is located 2^ miles further 
down, where the channel of the stream is contracted to a width of 550 feet 
by a ledge of sandstone which crosses it at about right angles. Between 
the dam and the mouth of the canyon is a continuous bed of gravel, in 
places half a mile wide, which, though lying on a heavy grade, constitutes 
the storage-reservoir. The dam was constructed by excavating a straight 
trench (shown in Fig. 101), 6 feet wide, from side to side of the channel, 
down to and into the sandstone bed-rock. In the center of the trench a 
wall of rubble masonry was laid, 3 feet wide at base, 2 feet at surface, using 
the cobbles excavated from the trench, and a mortar of Portland cement 
and sand. The mistake was made of not filling the entire width of the 
trench with concrete, thoroughly rammed between the side walls, which 
would probably have insured satisfactory water-tightness. As it was, the 
space each side of the wall was refilled with gravel, and the wall was not 
thick enough or sufficiently well pointed to be entirely water-tight. The 
general height of the wall is 40 feet, the maximum being 52 feet. Plan, 
profile, and section of the dam are shown in Fig. 103. Two gathering- 


wells are provided in the line of the wall, each 4 feet inside diameter, 
reaching from bottom to top. 

Three lines of drain-pipes, 8 and 10 inches diameter and made of asphalt 
concrete, laid with open joints, are placed inside the dam leading to the 
wells, the function of which is to gather the water and feed it to the wells. 
Outlet-pipes 14 inches diameter, one from each well, lead to either side of 
the valley. These are placed 13 feet below the top of dam and connect 
with a main leading to the pipe distributing system supplying the irrigated 
lands. When the reservoir is drained down to the level of these outlets 
further draft is made by pumping, which is required for about 100 days 
during late summer and fall. 

The cost of the dam is given at $50,000, and the volume of masonry 
was about 2000 cubic yards. It is a piece of amateur work, built without 
engineering advice, but it serves a useful purpose, though not at all commen- 
surate to its cost. It is, however, a type of dam that may be applicable to 
other localities more naturally favorable than this. 

The dimensions and capacity of this novel reservoir cannot be clearly 
determined, but its surface area is approximately 300 acres, its mean depth 
probably 15 to 20 feet, and its capacity equivalent to the volume of voids in 
the gravel, or 1300 to 1500 acre-feet. 

Agna Fria Dam, Arizona. — One of the tributaries of the Gila River, 
which joins it from the nortli, below the city of Phoenix, is the Agua Fria 
Eiver, heading in the mountains near Prescott, and draining some 140O 
square miles of mountainous territory. The Agua Fria Land and Water 
Company have erected a masonry diverting-weir across the stream, at a 
point 1^ to 2 miles above the northerly line of Gila Valley, and have pro- 
jected a storage-dam \\ miles higher up the stream, at a point called the 
Frog Tanks, to impound the flood-water for irrigation of the plains, 
beginning some twenty miles west of Phoenix. 

The dam is projected to the height of 120 feet above the bed of the 
stream. The width of the canyon is here 298 feet at the level of the sand, 
but at top the dam will be 1160 feet long. Sections of the .two dam-sites 
and profiles of the dams are shown in Fig. 105. Soundings have been 
made over the greater portion of the channel width, and what is presumed 
to be bed-rock has been found at depths of 9 to 15 feet, but for a space of 
50 feet no bottom was found with 24-foot sounding-rods. As the greatest 
depth to bed-rock at the diverting-dam below was but 40 feet, this depth has 
been assumed for the maximum of the unexplored 50 feet at the upper site, 
thus making the extreme height of the dam 160 feet. The reservoir to be 
closed by this dam will be 5 miles in length, flooding an area of 3200 
acres and impounding 108,000 acre-feet. With a dam of gravity profile, 
with base of 124 feet and crest 8 feet wide, the volume of masonry required 
is computed at 128,650 cubic yards. 



The enterprise, when completed, ia expected to fnniish vater for irrigat- 
iDg 50,000 acres of superb valley land that is now an absolute desert. A 
main canal baa been projected, S5 miles in length, with a capacity of 
400 second-feet, and some 4 miles of the beavieet woik was completed 


StcTKmoewm. SterioMortkMj. 

Fig. 103.— Plan and Pbofilb of I'acoiha Dak. 

from the dam down the left bank, to the point where the canal ia intended 
to cross the river by a 700-foot fltime. This canal is 18 feet on bottom 
and is to carry 8 feet depth of water, on a grade of 3.11 feet per mile. The 
diversion-dam, upon which about #100,000 had been expended at the time 
work was suspended in the fall of 1895, will have a top length of 640 feet, 
a maximum height of 80 feet, a top width of 10 feet, and a base of 65 feet. 



When finished it will contain 17,200 cubic yards of masonry, and will have 
cost in the neighborhood of $150,000. 

The only apparent parpose of this dam was to save the construction of 
a conduit, 1^ miles in length, in the canyon between the storage-dam proper 
and the diver ting- weir. The storage-dam must be built before the scheme 
is of any value, or before there is any water available for irrigation. 

The reasons which led to this error in judgment were, first, a misappre- 
hension as to the depth to bed-rock at the lower site. In fact, the dam was 
begun without a sufficient knowledge of what a great undertaking it was to 
be, and so much money had been expended before it was known or suspected 
that the extreme depth finally reached was to be so great that it was then 


Fig. 104.— Measxtrino-box upkd by Maclat Rancho Water Company. 
too late to abandon the work. The second reason was the confident expecta- 
tion that the volume of underflow that would be brought to the surface of 
the dam would reach from *' 500 to 1000 miner's inches," which, if real- 
ized, would have enabled the projectors to use the canal at once in the rec- 
lamation of the desert land entered under the United States Desert Land 
Act before the main reservoir could be made available. This " underflow'^ 
development was, however, a sore disappointment, as the flow when finally 
secured amounted to less than fifteen miner's inches, about what had been 
predicted by the writer when consulted on the subject a year or more 


The cross-sectional area of the two channels in which the underflow was 
passing beneath the surface is approximately as follows : 

East Channel 504 square feet. 

West " 2G35 *' *' 

Total 3139 '' " 

If the voids in the coarse sand with which these channels are filled could 
be assumed to be 28j< of the entire area, which they are approximately, the 



rate of flow established by the discharge of 16 inches (0.3 second-foot) 
would be precisely one mile per annum, a velocity whicli coincides with the 
observations of several authorities on the rate of flow through sand of that 
character. It may be noted in this connection that the volume of under- 
flow in sandy rivers is generally vastly smaller than the popular conception 
of it, and for this reason submerged dams for raising this underflow are 
usually commercial failures, except where the material of the stream-bed is 
a coarse gravel, with little or no fine sand intermingled. 


Tftp Of nnished Mosonnf 

Surface ofriw^bed 

Sectional Arm I9000 s^,ft. 


Fig. 105.-0 IIOSB sections op AgUA FrTA DfVERTING-DAM and bTOUAGl^-ltBbAKVOIB 

Dam, Auizona. 

The masonry used in the diverting-dam is a rough rubble, faced with 
coursed ashlar, mostly laid in a mortar of hydraulic lime of good quality, 
burned about 20 miles from the dam. (See Figs. 106 and 107.) For a 
portion of the work a small amount of Portland cement, made in Colton, 
California, was used. The rock was handled by a Lidgerwood cableway, 
with a span of 700 feet. The excavation of foundations, amounting to 
about 12,000 cubic yards, was accomplished by teams and scrapers, the 
water being handled by centrifugal pumps. 

In October, 1895, a flood came which poured over the fresh masonry 
for several hours to the depth of 8 feet, and finally carried away a section 
100 feet long, 12 feet deep, near the west end. The partial failure of the 
wall is accounted for by the fact that in laying the masonry each course was 
leveled off smoothly with mortar, in the fashion to which brick-masons are 
addicted in laying up house-walls. There was thus little bond between the 
courses, which is so essential in dam-work. A view of the dam, taken from 



the canal bank, is shown in Fig. 107, reproduced by permission from a 
paper entitled ''Irrigation near Phoenix, Arizona," by Arthur P. Davis, 
C.E., Hydrographer, U. S. Geological Survey, being No. 2 of the series of 
** Water-supply and Irrigation Papers," from which some of the data for 
the foregoing description are derived. 

In addition to the Frog Tanks reservoir-site the company have a second 
location, 8 miles higher up the river, where the gorge is but 262 feet wide 
at the river-bed, in solid rock, and but 500 feet wide at a height of 200 
feet. This basin is said to have a capacity of 150,000 acre-feet, with a dam 
150 feet high. The watershed, which drains the east slopes of the Brad- 
shaw Mountains, reaches summit elevations of 6000 to 8000 feet. A 
reasonable estimate of rainfall and run-off from this shed is a precipitation 
of 16 inches and an annual run-off of 15;^, which would yield 142,300 acre- 

Storage-reservoirs for Water-Supply Along the Line of the Santa F6 
Pacific Bailway in Arizona. — The northern portion of Arizona, traversed 
by the Santa Fe Pacific Railway, is an elevated plateau draining into the 
Colorado Canyon on the north, the Colorado Eiver on the west, and the 
Verde, Salt, and Gila rivers on the south. This region has a maximum 
elevation of over 7000 feet along the railway and receives a greater precip- 
itation than the lower altitudes in the southern part of the territory, but it 
is largely capped with volcanic lava and indurated ash, through which the 
water from rain and melted snow rapidly sinks and disappears. Living 
springs and streams are therefore infrequent, and the water-supply for rail- 
way purposes is so unevenly distributed as to necessitate the impounding of 
flood-waters in artificial reservoirs. This necessity is chiefly due to the 
general absence, in the valleys of that region, of beds of coarse sand and 
gravel, which constitute nature's storage-basins. The railway company, to 
avoid hauling water from point to point over this section of the road, has 
constructed several substantial dams for storage purposes at convenient 
points near the line of the railway, all of an interesting character in their 
construction from an engineering standpoint, although unimportant in the 
volume of water stored compared with works located in more favorable 
localities. These reservoirs are the following : 


Volume Stored. 





Character of I>am. 


Cubic Feet. 





Masonry, submerged 












Ash Fork 



Walnut Canyon 

MA80XUT DAMS, 219 

The Eiugman Submerged Dun. — About oue mile west of Eiagman the 
railway compaDj have a well Buuk ia the gravelly bed of Eailrond Cauyon, 
from which they pump water for filling their tank at Kingman to 
supply the town, as well as the locomotives of the railway. To increase 
thia supply and to furnish water by gravity to another tank 4 miles 
below, a masonry dam was built on bed-rock to intercept the underflow, of 
the stream and store wat«r in the gravel bed above the dam. The dam 
consisted of a slender masonry wall, 2 feet thick at top, 6 feet thick at base, 
and 16 feet high, crossing the canyon from side to side and reaching up 
nearly to the BurfiKse of the stream-bed. A trench was excavated in a 
straight line, the dam was built, and the gravel restored to its natural 
position, so that floods pass over its top unobstructed. The dam is thus 
entirely concealed from view. At the northerly end of the dam it was 

Pio. 108.— BuBUERGED Storaqe- AND DivBRTiNO-DAH, HEAJt EiNOHAN. Arizona. 

necessai-y to tunnel some distance under the railway in gravelly fonnation 
in order to carry the masonry to the bed-rock wall of the canyon on that 
side. Thia tunnel was made 12 feet wide, 20 feet high, and about 30 feet 
long, the top of the tunnel being 16 feet below the rails. A 6-inch cast- 
iron outlet^pipe is built through the dam 12 feet below the top, at one side. 
Four feet above the dam an elbow is placed, upturned vertically, and an 8- 
inch wrought-iron stand-pipe 10 feet long is inserted in the elbow. This 
stand-pipe is perforated with |-incli holes, placed ^ inch apart, for straining 
the water, the top being capped. The gravel reservoir is kept filled to the 
top of the dam by the natural underflow, and thus the town well is sup- 
plied and the lower tank automatically filled by gravity, the discharge 
being controlled by a float No shortage of water has been experienced 
since the dam was built in 1897. The dam is 173 feet long on top, and 
contains 320 cubic yards of masonry. (See Fig. 108.) 

The Seligman Dam.— This etrueture was begun June 25, 1897, and 
completed Feb. 28, 1898. It is the largest and most expeusive of all the 
structures of its class built by the railroad company. It is located three 
miles southeast of the town of Seligman, an important division terminal 


5104 feet above sea-level. The dimenBiouB of the dam &re as follows: 
Length at base, 145 feet; leugth ob crest, 643 feet; height, 08 feet; thick- 
neas at base, 47.7? feet; tbickoeas 3.1 ft. below the over How or 6.1 ft. below 
the crest, 5.14 feet; thickness at top, 1.75 feet. It is arched up-streata 
with a radius of 800 feet from the line of the water-face. The cubica 
contents are 18,161.4 cubic yards, divided as follows: 

Concrete in foimdatioQ 300 cubic yards. 

liough rubble in core 13,843.4 '• " 

Dressed ashlur 3,817.7 " 

Coping aOU.3 " " 

The work was done by contract, the railway company famishing the 
cement and delivering the stone, sand, and cement on cars to the dam-site, 
the contractor quarrying and loading the stone. The rubble aandstoue wns 

Fis. 109. — Selioman Dah, Arizoka. 

hauled 43 miles from Bock Bntte. on the S. F.. P. & P. R.R., the facing- 
stonp WAR hanled 175 mil^ from Holbrook, and the sand 150 miles from 
the Sacramento Wash. The contract prices were: $9 per yard for coping, 
$6.50 per yard for facings, 14.02 for rubble, and $2.81 for concrete. The 
total cost of the dam waa in excess of $150,000. 

The character of the masonry is well shown by the photograph (Pig. 
109) of the lower face during erection. Fig. 110 shows the water-face and 
end buttresses. The water appearing in the foreground is retained by a 
low earth dam that had been in use for some time prior to the construction 
of the masonry dam. The center of the dam is depressed two feet below 


the crest for a difltence of 340 feet, and curved in the form of the segment 
of & Tortical parabola for the overflow, which is the true form taken by 
falling water pouring over a weir. The maximuin capacity of this spillway 
ia 3400 second-feet, and as the watershed tributary to the dam is but 18 
square miles, the capacity provided is doubtless greatly in excess of what 
will ever be required. 

The outlets to the reservoir consist of two 8-inch cast-iron pipes, placed 
fi feet apart between centers, 64 feet below the crest of dam, on the north 
side of the ravine, and one of similar size on the south side, used as a 
waste. These pipes are connected with vertical stand-pipes, inside the 
reservoir, standing 10 feet high and 6 feet from the face of the dam. 
They arc of wrought iron, capped at top and perforated with §-inch holes, 
bored I inch from center to center. They form the intake and serve to 
strain the water, and keep out trash from the pipes. Gate-valves are 

Fio. 110 — Seliqhas Dam, Akizoha. View of Upper Pace Dtmiuo ComfPTRCcTioN. 
placetl in each pipe at the outside toe of the dam, and tlie pipes are reduced 
below the valves to 6 inches in diameter, where one of them is connected 
with the main pipe Hue leading to Seligman. The reservoir is 3000 feet 
long, and covers an area of 25^ acres. Its maximum capacity is 30,651,000 
cubic feet, or 703 acre-feet, of wliich one-third ia in the upper tan feet. 
The average loss by evaporation from January to June inclusive was found 
to be 0.03 foot per day, or an annual rate of 10.05 feet. This loss, applied 
to tJie mean surface exposed, would amount to 15;^ per cent of the entire 
volume in 809 days, assuming an average daily consum])tion of 16,000 
cubic feet during that time. A full reservoir is therefore expected to 
supply 120,000 gallons daily for 2J- years, after deducting evaporation. 
The catchment is somewhat unreliable, and the reservoir did not receive any 
water for the first two years after it was built. Fig. Ill illustrates the section 
of the canyon and the profile of the dam. The fine appearance which the 
immense mass of masonry presents inspires regret that it should be hidden 
from public view from passing trains, although it is easily accessible to 
those who care to step off at Seligman and inspect it. 


The Aah Fork Steel Dam. — This structure is tho first one of its class that 
has ever been erected, and lias so many novel features of an experimental 
cliaracter that it is specially interesting and instructive to the engineering 
profession. It was designed by F. H. Baiubridge, C.E., of Chicago, and 
was erected in 1897 on Johnson Canyon, at a point 4.3 miles east of Ash 
Fork, the jnnction of the Santa Fe Pacific with the Santa F^, Prescott and 
PhffiQix Railroad. The dam is one mile south of the track of the foimer 
road. Tho steel portion of the dam is 184 feet long, 46 feet maximum 
height for 60 feet in center. This steel structure connects with masonry 
walls at eacli end, which complete tlie dam across the gorge to a total length 
of 300 feet on top. The steel structure consists of a series of twenty-four 
triangular bents or frames, standing vertically on the lower side, with s 
batter of 1 to 1 on the upper. These frames are composed of heavy I beams. 

Fid. 111. — StcTtON AND Fkofiia OF Seuomak Daii. Aiuzuka. 

with diagonal stmts and braces, resting on concrete foundations, and placed 
8 feet apart, center to center, all well anchored into the bed-rock on the 
concrete base, and braced laterally in pairs. The dimensions of the bents 
vary with their height. The end bents are 12 to 21 feet in height, nine in 
number; four of the bents are 33 feet high, and the remainder from 33 feet 
to 41 feet 10 inches high. The batter-posts, to which the face-plates are 
riveted, are of 20-iiich I beams, the longest being 66.5 feet. The face of 
the dam is composed of curved plates of steel, f inch thick, 8' lOf" wide, 
and 8 feet long, the concave side being placed towards the water. They 
thus present the ajipearance of a series of troughs or channels between the 
supports. The bent plates do not extend into the concrete at the base, but 
the bottom course consists of flat plates, and the course next to the bottom 
is dished in the form of a segment of a sphere, making the transition 
between the curved and straight form. The edges of the plates are beveled. 
for calking, and riveted together with soft iron rivets. The joint between 
the steel and masonry stnictures at the ends is formed by embedding flat 
plates into the concrete, the face of which has the same slope as the face of 


the steelwork. The abutments project 8 inches beyond the line of the face- 
plates. The masonry- work consists of 342.6 cubic yards of rubble and 
1087 cubic yards of concrete, and there was used in the work a total of 
1751 barrels of Portland cement. The work was begun October 7, 1897, 
and completed March 5, 1898, under the supervision of R. B. Burn?, 
Chief Engineer, Santa Fe Pacific Eailway, Mr. W. D. Nicholson, Assistant 
Engineer, being directly in charge. 

The dam is designed to carry flood-water over the top of the stee} 
structure. The steel plates are carried over the top of the frame, forming a 
rounded apron to carry the overfall beyond the line of posts. This apron, 
connecting with the curved inner plates, forms a series of trough-like 
cliannels between posts, 1.3 feet deep at center. The abutment wall at the 
east end of the dam is 2 feet higher than the bottom of the spillway chan- 
nels, and that at the west end is nearly 8 feet higher. The rock at the 
dam-site is volcanic in origin, very hard on the surface where exposed, but 
containing occasional pockets of ashes or cinders, and badly broken by seams. 
The rock excavated for foundations was used for concrete and rubble 
masonry. The concrete was mixed in the proportion of 1 of Portland 
cement to 3 of sand and 5 of broken stone. The outlets consist of two 
C-inch cast-iron pipes placed 6 feet apart, with perforated stand-pipes, 10 
feet high, inside the reservoir, similar to those at the Seligman dam. The 
pipes are embedded in the concrete 28 feet below the top of the dam, and 
reduced to 4" diameter at a point 16 feet below the gates that are placed at 
the toe of the masonry. The fall in the pipe-line, 4.3 miles long, is 200 
feet from base of dam to the top of the water-tank at Ash Fork. 

The reservoir has a capacity of 37,023,000 gallons, or 4,950,000 cubic 
feet, and receives the drainage from 26 square miles of watershed. The 
average consumption is estimated at 90,000 gallons per day, or three-fourths 
that of Seligman. The loss by evaporation is expected to be 40^ to 50^ of 
the total supply, but, inasmuch as it will receive water from summer rains 
as well as from melting snows, it is anticipated that the supply will be main- 
tained equal to the ordinary demand. 

It cannot be said that this experimental steel dam, the first of its class 
that has been erected, is entirely successful, and it is doubtful if the com- 
pany, with the experience already had in two years of service, would care 
to repeat it or recommend that class of construction in lieu of something 
more substantial and permanent. It has been found difficult, and in fact 
impossible, to make a tight joint between the steel and masonry work. The 
structure leaks quite badly at both ends. The water also follows down the 
face-plates on the up-stream side and comes out on the down-stream side, 
notwithstanding that concrete has been rammed in on both sides of the 
plates for a distance of 5 feet. 

The total weight of steel in the structure is 478,704 lbs., which was 


framed and erected by the Wisconsin Bridge and Iron Company at a cost of 
(55.78 per ton of 2000 lbs. The detailed cost of the entire dam is given 
as follows: 


Lumber, etc., in buildings 1659.94 

Explosives and tools used in excavating 937.20 

Corrugated iron and nails in facing 181.02 

Hubble stone 155.25 

Paint and oil for painting dam 213.49 

Cement, 1926 barrels 6,774.92 

Steel in dam, erected 13,351.05 

Fencing for reservoir 409.26 

Total material *21,C82.13 


Spur-track $15.00 

Building camp 272.75 

Hauling material 3,378. 10 

Excavating and laying masonry 15,440.36 

Engineering and superintendence 3,102.83 

Plans and tests of metal 233.63 

Freight on metal 1,651.30 

Total labor 24,003.97 

Total cost of dam complete. , 145,776.10 

The pipe-line to Ash Fork cost 15,978.70 

Figs. 112 and 113 give an excellent general idea of the construction. 
Fig. 114 shows a portion of the reservoir, and represents clearly the igneous 
rock formation of the canyon in which it is located. 

The Williams Dam. — The first of the series of dams for storage erected 
by the railway company was constructed near the town of Williams in 1894. 
It has an extreme height of 46 feet, is 385 feet long on the crest, 50 feet 
long at the base, where its thickness is 32 feet. The thickness at top is 
4 feet. It is arched up-stream with a radius of 573 feet from the line of 
the vertical water-face. The dam contains 5226 yards of masonry, and 
consumed 3640 barrels of cement in construction. Its cost was $52,838* 
The dam has been a serviceable structure. The capacity of the reservoir is 
110,000,000 gallons. The watershed area is not definitely known, but is 


Th« Walnut Cannon Sam. — Walnut Canyon is a tributary of the Little 
Colorado Kivor, which heads in Mormon Mt. a little south and east ot 
Flagstaff. Tlie watershed area above the dam is 12ii square miles, which 

Fia, 113.— Abb Fokk, Arizona, Stekl Dam, View op Steel Constbcction 
FROM Lower ISide. 

ordinarily affords a much greater run-off than the storage capacity oC the 
reaervoir. The geological formation of the canyon walls at the dum-sitc is 
sandstone in heavy layers or strata in nearly level beds. The bottom of the 

Fio. 113.— Ash Fork, Stbel Dam. Showing Fraue rbidt to obceivb Plates 

canyon was so filled with debris of earth and stone that it was necessary to 
excavate 28 feet below the surface to reach bed-rock, on which the dam waa 
erected. The width at this point was hut 30 feet, at the surface of stream- 
bed 130 feet, and at the top of the dam 268 feet. The extreme height of 


the dam is 77.6 feet. Ita thickness at base is 61.5 feet. The water-face is 
vertical, while the upper face has a butter of 7^ inches to the foot botween 
the vertical curves at top and toe. The top is rounded in parabolic form 
to a thickness of 13 feet at a point 10.4 feet below the crest, to form an 
easy overdow for surplus waste water, while at the base the wall is vertical 
for 10 feet, above which is a vertical curve, tangential to the horizon, pass- 
ing through 58° of arc, to a point 46.4 feet below the top, where the thick- 
ness is 35.5 feet. This design forms an exceedingly massive structure witli 
unusually large factor of safety. The dam is arched up-stream with a radius 

F|o. 114.— Abh Fork Heservoih. 

of 400 feet to the line of the water-face. The masonry consisfs of 5244 
cubic yanls of heart nibble, 1572 cubic yards of facing ashlar masonry in 
irregular courses, with dressed beds, and 80 cnhic yards of cut coping-stone— 
a total of 698C cubic yards. There were GOTO barrels of Portland cement 
used in construction. The toial cost, exclusive of excavation, was about 
*55,000. The stone used was quarried at the dam-site and was of good 

The outlets consist of '.wo 10-inch cast-iron pipes, placwl 6 foot apart, at 
an elevation of 30.4 feet below the top of the dam, 10 feet al)ove the stream- 
bed. Vertical strainer -pi pes, 10 feet high, are placed over the upper ends 
of the outlets in the reservoir, 6 feet from the face of the dam. Outside, 
the pipes are controlled by 10-inch Ludlow gates, and are reduced to 8 
inches liameter below the gates. The main pipe-lint from the dam follows 
the canyon for 4,J miles to the railroad crossing, and thence follows the truck 
easterly 12 miles further to a tank. 

Fig. 115 is a view of the dam from below when nearly compleicd. Fig. 
116 shows the profile of the dam as constructed, and a section of the canyon 
at the dam-site. 


The reservoir was filled for the first time on the 8th of March, 1898, and 
if it had been water-tight should have supplied an estimated consumption of 
60,000 gallons daily for more thaii two years, allowing for a daily evapora- 

Fio. 11.''.— Walnut Castos Dam, Akizuna. 

tion loss of 0.03 foot. The water, however, disappeared very rapidly, and 
by September 20th was all gone, having lasted but 196 days instead of the 
estimated 356 days. The draft for consumption on the road was not greater 

than had been assumed in the original calculation, and the excessive loss 
could only be accounted for by percolation through the sandstone or through 

the seams separating the underlying limestone from the sandstone. It is 
hoped that the reservoir will ultimately puddle itself and become tight, and 


efforta are being made to assist tlie proceBs by plowing and loosening clay 
soil at points above. It is unfortunate that the usefulness of such a line 
Btructure should be curtailed by this unexpected leakage in the walla of the 
reservoir, but it is possible that the loss of water may gradually lessen and 
finally cease. This experience illustrates, however, one of the vicissitudes 
attending the impounding of water. Under the most favorable condiiions 
the annual loss by evaporation on this reservoir would be nearly 35^ of the 
volume of storage capacity. Ko mn-ofE was caught during the summer of 
1899, and in the latter part of August it was still dry. The entire series of 
reservoir dams have been constructed under the supervision of Mr. R. B. 

Burns, Chief Engineer, Santa Fe Pacific Railway, to whom the writer is 
indebted for the data coucernlug the works and the views which illustrate 

Lynx Creek Dam, Arizona. — This structure was located 13 miles east of 
Prescott, Arizona, and was designed to impound water for hydraulic mining 
on Lynx Creek, some 4 miles below. It was intended for an ultimate height 
of 50 feet, and was started with a base of 28 feet. When it had reached 
a height of 28 feet on the np-stream side, the lower edge of the crest being 
2 feet higher, it was roughly squared off with the intention of adding the 
remaining portion at a later date, when a sudden flood overtopped the dam 
and ruptured it, taking out about 35 feet of the masonry down to the bed- 
rock. The break is shown by the view, Fig. 117, looking up-stream. It 
occurred in 1891, and the dam has never been rebuilt. The dimensions of 
the dam were ample to withstand any overflow to be expected from tlie 


floods drainiDg the tributary waterehed of 30 square miles of territory, from 
6500 to 7500 feet in elevation, had the masonry been of reasonably good 
quality. The failure, therefore, was clearly due to poor workmanship and 
unsuitable materials. The dam was 150 feet long on crest, and was built 
with a central angle of about 165° opposed to the direction of the current, 
the up-stream face being vertical. The wall consisted of a thin facing of 
hand-laid masonry, not over one foot thick, the core being filled with a weak 
concrete of fine gravel, stone, spawle, and sand. The section of the dam as 
constructed is clearly seen from the photograph (Fig. 118). Considerable 

Fio. lis. — Lynx Creek Dau, Arizona. Skction showinu Faciho Walls ahd 


lime was used with the cement, which was of poor quality, and the concrete, 
though ten years old, possesses so little cohesion that it may be crumbled 
with a light touch. The cement used averaged but 1 barrel to 6 cubic 
yards of masonry. The failure of the dnm, under all the circumstances. 
might have been anticipated. It is referred to here merely as an example 
to illustrate the natural consequences that must follow any carelessness or 
lack of attention to proper selection of materials and skill of construction 
in masonry or concrete dams that must withstand the erosive action of 
floods as well as normal water-pressure. 

Concrete Dams of Portland, Oregon. — Among recent constructions of 
concrete masonry three dams designed and erected by the writer for the 
water-works of Portland, Oregon, in 1894, may be classed as worthy of note. 
They were built for the purpose of forming distributing reservoirs, and were 
located across natural ravines, or embayments in the hills, the reservoir space 
being largely augmented by excavation, and the slopes covered with a lining 


of concrete. One of these dams, shown in Fig. 119, closes reservoir No. 1 
on the side of Mount Tabor, and is 35 feet high, 300 feet long, with a base 
of 18 feet and top width of 6 feet. The reservoir capacity is 12,000,000 
gallons. Behind the dam the material excavated from the reservoir was 
placed, forming a heavy embankment whose top width is 100 feet. This is 
such an immovable barrier that the chief function of the concrete wall is to 
act as a retaining-wall for the inner slope of the earth-fill, and to form a 
part of the reservoir lining. The reseiToir receives the water delivered by a 
steel-pipe line 24 miles long, amounting at maximum capacity to 22,400,000 
gallons daily, and distributes it to three other reservoirs, one of which is but 
2000 feet distant, shown in the photograph Fig. 121, and the other two are 
five miles away, across the Willamette Kiver, and designated as reservoirs 3 
and 4 (Fig. 120). Reservoir No. 3, high service, has a dam 200 feet long which 
is arched up-stream with a radius of 300 feet. Its height is 60 feet, base 40 
feet, top width 15.5 feet, carrying on its crest a driveway of the City Park, in 
which it is located. This is the only dam of the three which is curved, and 
the only one which does not exhibit some slight expansion-cracks. The dam 
forming reservoir No. 4, low service, is 50 feet high, 350 feet long, and 40 
ieet wide at base. The faces of these two dams, both of which are in the 
City Park, are moulded and chiseled to resemble stone, and considerable 
ornamentation has been done on the parapets and about the gate-houses, as 
shown in Fig. 120, to which the concrete and iron construction lends itself 
to good advantage. It is needless to add that the dams of the dimensions 
given are of safe gravity profile, with ample factors of safety. 

Basin Creek Dam, Montana. — This dam was built in 1893-95 to impound 
water for a portion of the domestic supply of the city of Butte, Montana, 
and is located 13 miles south of the city, on Basin Creek. It was designed 
by Chester B. Davis, M. Am. Soc. C. E., and constructed under direction 
of Eugene Carroll, C.E., Chief Engineer. The construction was described 
in Engineering Neios, December 17, 1892, Aug. 7, 1893, and Sept. 5, 1895, 
in communications prepared by these engineers, from which the following 
data have been taken. The dam is constructed of large stone, with spaces 
thoroughly filled with concrete, made of crushed granite 3 parts, sand 3 
parts, and Yankton Portland cement 1 part. It was designed for an 
ultimate height of 120 feet above the lowest foundation, assumed to be at 
elevation 5780 feet above sea-level, or 30 feet below stream-bed, and was 
curved up-stream with a radius of 350 feet from its water-face. The thick- 
ness at base was to be 83 feet, and at top 10 feet ; up-stream face vertical. 
At full height it. would impound about 1,000,000,000 gallons (3069 acre- 
feet), covering' an area of 130 acres to a mean depth of 23.6 feet. The dam 
was not completed higher than to the 5860-foot contour, or 40 feet below 
the projected crest, although its actual maximum height is 88 feet, of 
which 28 feet is below the stream-bed level, and it now can impound 


200,000,000 gallona. The contents of the dam are 11,500 cnbic yards of 
masonry. Its top length ia 259 feet. Three 20-inch pipes are laid through 
tlio dam at its center, at the creek-bed level, two of which are nsed for blow- 
off. These pipes are controlled by plain cover-valves, resting on upturned 
elbows inside the dam, and raised by a windlass from the top. Gate-valves 
on the pipes below the dam give aecondary control. 

The materials of construction were hauled by a Lidgerwood cableway, 
with a clear spaa of 893 feet, the main cable being 2^ inches diameter, siu- 

Pia. 121.— Rkber VOIR No. 2, Portland, Oregon, showing AERATiiia PoDNTAUt 


pended 60 feet higher than the 120-foot crest-line. This cableway crossed 
over the quarry, and was stretched on the chord of the inner face of the 
dam. Tlie loads were swung either side of this line by using a single horse 
pulling from a rope attached to the load and leading back over a sheave to 
a snubbing- post. The limited space made the use of derricks for this 
purpose inconvenient. For a distance of 9 miles from tlie dam the main 
conduit to the city consists of a wooden-stave pipe, 34 inches in diameter, 
built by tlio Excelsior Wood-stave Pipe Co. of San Francisco, of which 
Mr, D. C. Henny is manager and engineer. 

A Dam under 640-foot Head.— A curiosity in the line of masonry dams 
is the one bnilt in tho Curry mine, at Norway, Michigan, to close a drift 
6 feet wide, Tt feet high, and thereby cut off a troublesome stream of water. 
It was built of sandstone, arched against the direction of the pressure, with 
a thickness of 10 feet, and laid in II il ton-cement mortar, in the proportion 


of 1 to 2 of sand. The dam (Fig. 122) is nearly 800 feet below the surface, 
aud when the water fills behind it is subjected to a pressure of 277 lbs. to 
the square inch, equal to a etatic head of 640 feet, or a total pressure 
against the dam of over 800 tons. The dam was designed and built by 
Wm. Kelly, M. Am. Inst. M. £., and doubtless affords the moBt extraordi- 

Ungltudinal S«<;tl«n. 
Pig. 122.— HASONitT Daii unber 640-rooT Head, the Gn&ATEer Recobp&d 
■\VATER-rnE8SDRE ON Masonrv. 

uary precedent on recoi'd of masonry under such estremely high pressure. 
It was made practically water-tight by building a brick wall, 22 inches 
thick, 26 inches above the face of the dam, filling the intermediate space 
with concrete, and placing a quantity of horse-manure against the brick- - 
work, which was held in position by a plank partition or bulkhead. When 
finally tested the leakage was but 7 gallons per minute. The dam cost 
»i84.27. (&ee, Engineering Neios,~DiiC. 10, 1397.) 

New Cioton Dam, Few York. — The great dam in process of erection 
for increasing the water-supply of New York City will, when completed, be 


the highest as well as the most costly dam in America. It will consist of a 
central masonry dam 730 feet long, 290 feet maximum height; a masonry 
overflow-weir about 1000 feet long, extending up-stream from the north 
end of the masonry dam ; and an earthen dam with a masonry core- wall, 
about 440 feet long, continuing the masonry dam to the south side of the 
valley. The three sections of the dam, including the weir and core-wall, 
will thus form a continuous masonry wall across the valley, which will be 
about 1300 feet long on top. The masonry dam proper will have a base 
width of 185 feet and crest width of 18 feet, exclusive of the parapets pro- 
tecting the roadway. The extreme height of the dam above the original 
stream-bed is to be 163 feet. The crest is to be 14 feet higher than the lip 
of the overflow- weir, and the top of the earth dam is to be 10 feet higher 
than the masonry. The contract for construction of the dam was let to 
Jas. S. Coleman, Aug. 31, 1892, for $4,152,573, of which $2,876,000 had 
been expended for work done to January 1, 1899. The ultimate cost will 
largely exceed the contract price, on account of a great increase of depth 
beyond the original expectations. The stone is handled by three lines of 
cableway with spans of 1200 feet between supports, and by 30 steam- 
derricks located on the dam. It is quarried 1^ miles distant and brought 
to the work by a narrow-gauge railway, on which 7 locomotives and 83 flat- 
cars are employed. Thirteen derricks with independent steam hoisting- 
engines are used in the quarry. The volume of water pumped from the 
excavations to and into the bed-rock has not exceeded 5,000,000 gallons 
daily. This volume, compared with the approximate area of the cross- 
section of the valley from bed-rock up to the level of the river-bed, indi- 
cates a maximum movement of the subterranean water down the valley at 
the rate of about 2^ miles per annum, assuming that none of the water 
pumped was returning to the pit from the lower side. The watershed area 
above the dam is 360.4 square miles. The reservoir when full will sub- 
merge an area of 3360 acres. The plans for the dam were designed by 
Alphonse Fteley, Chief Engineer of the Aqueduct Commission. Construc- 
tion is under the immediate charge of Charles S. Gowen, Division Engineer, 
and B. S. Value, Assistant Engineer. 

The original estimate of the volume of masonry of all kinds required in 
the dam was about 679,000 cubic yards, of which the greater portion, or 
470,000 yards, was to be rough rubble laid in American (natural) cement 
mortar, the remainder to be laid with artificial Portland cement. 

The Titicns Dam, New Tork. — This structure is a part of the system of 
storage for the supply of New York City, and was built in 1890 to 1895, at 
a cost of $933,065. It resembles the New Croton Dam in general design, 
in that it is a combination of masonry and earth, the higher portion in the 
center of the valley consisting of masonry, flanked on either side by earthen 
embankments, provided with a central core-wall of masonry. The main 


masonry dam is 135 feet high above foandation, 109 feet high above original 
surface, 75.2 feet thick at the level of the stream-bed, 20.7 feet thick at top, 
and 534 feet long. The earthen dams are 732 and 253 feet long, respectively, 
the total length of dam being 1519 feet. A waste-weir, 200 feet long, built 
in steps on the lower side, is carried over a portion of the main masonry 
dam. The masonry consists of rough rubble, faced on either side with cut 
stone, laid in regular courses. The earthen dam is 9 feet higher than the 
crest of the spillway. It is 30 feet wide on top, with slopes of 2^ to 1. 
The core-wall is of rubble masonry, 6 feet on top and 17 feet thick at a 
depth of 98 feet. It reaches to a maximum height of 124 feet above base. 
The greatest depth of water is 105 feet. The dam was planned by A. 
Fteley, Chief Engineer, and construction was originally in charge of Charles 
S. Gowen, who was subsequently succeeded by Alfred Craven as Division 
Engineer, and M. S. Sidgway, Assistant Engineer. 

The Sodom Dam, Hew York. — This is a purely masonry structure, built 
across the east branch of the Croton Eiver in 1888-93, by the Aqueduct 
Commission of New York, and, in connection with the Bog Brook dams 1 
and 2, forms what is known as ** Double Reservoir 1.'* The reservoirs were 
connected by a tunnel, 1788 feet long, by which the surplus water from the 
Sodom dam is made to supply the other reservoir, whose watershed was but 
3.5 square miles, while that tributary to the Sodom reservoir was 73.4 square 
miles. The tunnel thus equalizes the supply from the two watersheds. The 
combined storage capacity of the two reservoirs is about 9,500,000,000 gal- 
lons. The Sodom dam is 500 feet long on top, 98 feet high above founda- 
tion, 78 feet above stream-bed, and the masonry has a bottom thickness of 
53 feet, and is 12 feet wide at top. It contains 35,887 cubic yards of rubble 
masonry, chiefly laid in Portland-cement mortar, mixed 2 to 1 and 3 to 1. 
A continuation of the masonry dam is carried along the crest of the ridge, 
nearly at right angles to the wall, in the form of an earthen embankment, 9 
feet high, 600 feet long. In extension of this bank is a masonry overflow, 8 
feet high, 500 feet long. 

The cost of the dam was $366,490. It was planned by Chief Engineer 
Fteley, and constructed by Geo. B. Burbank, Division Engineer, and Walter 
McCuUoh, Assistant, later Division Engineer. An interesting account of 
the dam is to be found in a paper prepared for the American Society of Civil 
Engineers in March, 1893, by Mr. McCulloh, from which it appears to be 
one of the few masonry dams that were quite water-tight from the first filling 
of the reservoir, although "sweating" appears at several points on the lower 
face. The dam was built by the aid of a 2-inch cableway, stretched along 
its axis, with a span of 667 feet between towers. The Sodom reservoir 
covers an area of 574.9 acres and impounds 4,883,000,000 gallons. The 
Bog Brook reservoir, with which it is connected, floods a surface area of 
410.4 acres. The Bog Brook dams are of earth with masonry core. Dam 


Nor. 1 is 60 feet high and holds 54 feet mazimum depth of water. It is 25 
feet wide on top. The core- wall is 10 feet thick at base, 6 feet at top. Dam 
No. 2 is 25 feet high. The cost of the two dams was $510,430. 

The Boyd's Corner Dam, Hew York. — In 1866 the Croton Aqueduct 
Board of New York began a masonry dam near Boyd's Cornere, on the west 
branch of Croton River, which was completed in 1872. The dam contains 
27,000 cubic yards of masonry, of which 21,000 yards are concrete hearting 
and 6000 yards are cut-stone facings. The dam has a maximum height of 
78 feet, is 670 feet long on top, 200 feet long at level of stream-bed, 63.6 
feet thick at base, 8.6 feet at top. The base is laid with a batter of ^ to 1 
on each side to the original stream-level, 60 feet below the crest, where an 
offset of 1.5 feet was made on each side, and the dam was then carried up 
vertically on the water-face, and given a batter of 0.4 to 1 on the lower side. 
The reservoir covers 279 acres and impounds 2,722,700,000 gallons of 

The Indian Kiver Dam, Hew York.— This important structure was 
erected in 1898 for increasing the size of Indian Lake and thus store water 
to supply the Champlain Canal, to add to the water-power, and to improve 
the navigation of Hudson River. It is located in Hamilton County in the 
northern part of New York State, on a tributary of the Hudson, at an 
elevation of 1655 feet at the high-water line. The dam is a combination 
masonry and earth structure, straight in plan, the masonry portion being 
47 feet in extreme height, having a base width of 33 feet, a thickness on 
crest of 7 feet, and a total length of 207 feet. The earth embankment is 
a continuation of the masonry, 200 feet long, 15 feet wide on top, with 
inner slopes of 2^ to 1, paved with 12 inches of stone riprap. The outer 
slope is 2 to 1. Through the center is a core- wall of masonry, 4 feet thick 
at base, 2 feet at top, reaching to within 2 feet of the crest of the embank- 
ment. The end of the embankment next the dam is supported on the 
down-stream side by a masonry spur-wall at right angles to the dam. The 
embankment rests on hard-pan, into which the core-wall is carried down 
uniformly 4 feet thick to depths of 8 to 20 feet, filling the trench cut 
for it. 

On the opposite or west end of the dam a spillway was excavated in 
granite, having an effective length of 106.5 feet and a depth of 6 feet, to 
the bottom of the floor-stringers of the foot-bridge which spans it and 
which rests on five masonry piers. The capacity of discharge is estimated at 
5000 second-feet. The coping is made of large, selected stones firmly 
doweled to the masonry. A logway, 15 feet wide, whose crest is 17 feet 
below the top of the dam, is provided through the masonry. It is closed 
with 45 wooden needles, 4" X 8", 20 feet long, which are handled by block 
and tackle. The outlets to the reservoir consist of two 50-inch steel pipes, 
controlled by Eddy flume-gates, and having a discharging capacity of 1500 
second-feet with full reservoir. The gates are inside of a tower, on the 


exterior of which are auxiliary sluice-gates of wood^ raised by screws. > A 
6-inch by-pass pipe enters the tower from the reservoir, by which the tower 
is filled and the pressure relieved from the wooden gates, so that they can 
be readily raised. 

The total actual cost of the work, including $13,000 for clearing, was 
$83,555, the contract price being $92,000. Under the most favorable con- 
ditions the cost per cubic yard for the masonry was as follows : 

Cement $2.00 

Sand 15 

Quarrying stone 35 

Labor of laying masonry 53 

Labor of pointing masonry 15 

Labor of mixing mortar, concrete, and crushing 20 

General expenses, superintendence, etc 27 

Total $3.65 

The cement used was made at Glenn's Falls, N. Y., of the "Ironclad*' 
brand of artificial Portland. 

The reservoir formed by the dam has a storage capacity of 4,468,000,000 
cubic feet, or 102,548 acre-feet, and floods an area of 5035 acres. The 
original lake covered 1000 acres, and the new dam raised the mean surface 
of the lake 33 to 34 feet. The tributary drainage-area above the dam is 
146 square miles, the run-off from which can be safely estimated to fill the 
reservoir every year. 

The dam was built for the Forest Preserve Board of New York State by 
the Indian Eiver Company. It was planned by Geo. W. Rafter, M. Am. 
Soc. C. E., and consttncted under his supervision by Wallace Greenalch, 
Jun. Am. Soc. C. E., as Assistant Engineer. 

For further details of this interesting work the reader is referred to Eft- 
gineering News of May 18, 1899, containing descriptive illustrated papers on 
the subject by Messrs. Saf ter and Greenalch. 

Cornell TTniversity Dam, Hew York. — In 1897 an overflow masonry dam 
was built across Fall Creek near Ithaca, N. Y., as a portion of the hydraulic 
laboratory plant of Cornell University. It is curved in plan on a radius of 
166.5 feet, and is 153 feet long on top, with a maximum height of 30 feet, 
and a gravity section, vertical up-stream, and stepped on the lower face. It 
is located at the head of Triphammer Falls, in a picturesque gorge, cut 
deeply into the shale formation of that region, where the total fall is about 
400 feet in a mile. The stream drains a watershed of 117 square miles, on 
which the mean precipitation from 1880 to 1897 was 35.22 inches. The 
mean flow is about 175 second-feet, ranging from a minimum of 12 to a 
maximum of 4800 second-feet. In times of flood the water discharges over 
the crest of the dam and over a natural spillway ledge at one end of the 
dam, a total width of 267.5 feet, made up of 134.5 feet on the dam and 133 
feet on the natural spillway. 


The dam is of gravity section^ and made of concrete, composed of four 
parts of hard, clean, argillaceous shale, two parts of sand, and one part of 
" Improved cement/' The *' Improved cemenf is a mixture of Eosendale 
and artificial Portland in the proportion of weight of 3 to 1, ground together 
in the clinker state, and costing one-half the cost of pure Portland cement. 

One of the interesting and unusual features of the construction of this 
dam was the provision made for concentrating the contraction due to tem- 
perature changes in the concrete to a central point of weakness. This was 
done by leaving a 5-f t. circular opening through the dam during construc- 
tion, connecting with which was an open well extending up through the 
heart of the dam to its crest. At this point the section was thus reduced 
to 60;^ of the normal, and shortly after completion the wall cracked for one- 
half its height down through the well. During unusually cold weather, 
when the crack was widest, the opening through the dam and the well were 
filled with concrete, and the contraction-crack was thus effectually closed. 

The dam and other works connected with the entire plant designated as 
the hydraulic laboratory were designed by Prof. E. A. Fuertes, M. Am. 
Soc. C. E., Director of the College of Civil Engineering. Construction 
was in charge of Mr. Elon H. Hooker, Resident Engineer. Mr. Ira A. 
Shaler, M. Am. Soc. C. E., was contractor for the work. A full descrip- 
tion of the laboratory is given in Engineering News^ March 2, 1899. 

The Bridgeport Dam, Connecticut. — The town of Bridgeport, Conn., 
having a population in 1890 of 48,890, is supplied by a number of storage- 
reservoirs, one of which is formed by a masonry dam across Mill River, built 
in 1886. Its general dimensions are as follows : 

Maximum height 42.5 feet. 

Bottom thickness 32.0 ** 

Top thickness 8.0 -^ 

Length at crest 640 

Length at base 50 

The structure is composed of rubble masonry built of gneiss rock laid in 
a mortar of Rosendale cement and sand in the proportion of 1 to 2. The 
lower face of the dam is built in steps. The outlet from the gate-chamber 
is a 30-inch cast-iron pipe, controlled by a gate-valve in the chamber. The 
latter structure is built against the dam, is 10 X 16 feet inside, in two com- 
partments, between which a fish-screen is placed. Three 30-inch openings, 
at different levels, controlled by gates, lead from the reservoir to the outer 
compartment. The spillway, at one end of the dam, is 80 feet long, 5 feet 
deep. The reservoir covers 60 acres and has a capacity of 240,000,000 gal- 
lons (737 acre-feet). The dam has leaked so much as to require an earth 

 '* The Design and Construction of Dams/' by Edward Wegmann, p. 85. 


The Wign'^am Dam, Connecticut. — The city of Waterbury, Conn. (pop. 
28,646 in 1890), constructed a masonry dam in 1893-94 to store water in a 
reservoir located on West Mountain Brook and receiving the drainage from 18 
square miles of watershed. The dam was designed and built by Robt. A 
Cairns, City Engineer. It was planned for an ultimate height of 90 feet, at 
which its full length on top will be 600 feet, and it was completed with full 
section to within 15 feet of the ultimate crest, and there stopped, as the 
storage at that level was sufficient for present needs. The base thickness is 
63.08 feet, and it is 12 feet thick on the crest. The cubic contents of the 
completed portion are 14,887 cubic yards, of which 5754 yards are laid in 
Eosendale cement, and the remainder in American Portland cement mortar. 
The cost has been $150,000. The present capacity of reservoir is 
335,000,000 gallons (1028 acre-feet), which will be increased to 714,000,000 
gallons when the dam is completed. A temporary wasteway, 82 feet long, 
2 feet deep, has been made at one end of the dam, which is of insufficient 
capacity. The completed dam will have a wasteway 100 feet long over a 
rocky ridge some distance away, and another 78 feet long at the dam. An 
earth embankment is required to close a gap in the reservoir, as an auxiliary 
to the masonry dam. This will be 35 feet high when finished, but is built 
only to a height of 20 feet. 

The Austin Dam, Texas. — The city of Austin, Texas, the capital of the 
State, with a population of about 25,000 inhabitants, has erected one of 
the most notable masonry dams of the United States, across the Colorado 
Kiver, 2^ miles above the city, for power-development purposes. The dam. 
Fig. 123, was built in 1891-92. It was designed by Mr. Jos. P. Frizell, 
M. Am. Soc. C. E. of Boston, and about two- thirds completed by him. He 
was succeeded by Mr. J. T. Fanning. The dam proper is 1091 feet long 
between bulkheads and 68 feet high. It is vertical on the up-stream face, 
while the down-stream face is inclined at a batter of 3 in 8, terminating in 
a vertical curve of 31 feet radius, while the crest is rounded on a radius 
of 20 feet on lower side, forming an ogee curve that has the general shape 
of the trajectory of falling water. 

Mr. Frizell's original design contemplated a flat top for the purpose of 
facilitating the erection on the crest of a series of movable flashboards, 
or some other form of falling dam, that could be lowered in flood-time, but 
would permit of increased storage during low seasons, and the development 
of a more uniform volume of power at low and high water. 

The power is used for pumping water for city supply, for electric 
lighting, propulsion of street cars, and general manufacturing. Its volume 
is estimated at 14,636 horse-power for 60 working hours weekly. 

The dam is straight in plan, and contains about 88,000 cubic yards of 
masonry, of which 70,000 yards arc of rough rubble, made of the limestone 
quarried near the site, and 18,000 yards are of cut-stone range-work, in 

XA80NBT DAMS. 245 

which Bnmett County blue grauite was used, brought a distance of 80 miles. 
The entire work was done by contract, at a cost of $11 to %\5 per yard for 
the cut-stone masonry, and t3.60 to 14.10 per yard for the rubble, the 
larger sum being for work in which Portland cement was required. The 
cost of the dam and head-gate masonry was $608,000, and the entire 
expenditure, including dam, power-house, reservoir and distributing sys- 
tem, lighting-plMit, etc., was $1,400,000, for which amount the city voted 
its bonds May 5, 1890. 

The dam is founded on limestone rock throughout, the river here 
flowing through a gorge with cliffs rising from 70 to 125 feet in height 
above the river. Lidgerwood cableways were employed in placing the stone 
and for hauling all materials. 

The Colorado River at Austin drains an area of 40,000 square miles, 
from which the discharge has a range of from 200 to 250,000 second-feet. 

The reservoir formed hy the dam is very long and narrow, extending 
hack 19 to 33 miles up the river and having an average width of but 800 
feet. Its surface area is 1836 acres, and the capacity at the time the dam 
was finished was 53,490 acre-feet, the mean depth being 29.1 feet, or 42.5% 


of the maximum. The dam was completed in May, 1893, and the water 
first overflowed the crest of the dam on the 16th of that month. 

Four years subsequently, in May, 1897, Prof. Thomas U. Taylor, of the 
University of Texas at Austin, made accurate soundings of the lake tot 
determine the volume of silt which had accumulated in four years, and 
ascertained that the deposit amounted to 968,000,000 cubic feet (22,227 
acre-feet), or 41.54% of the original capacity. The greatest depth of fill 
was at the dam, 23 feet; three miles above it was 16.5 feet deep at the 
maximum; seven miles above, 20 feet; 9.3 miles above, 21.3 feet; 14.6 
miles above, 15.3 feet; 15.9 miles above, Q.Q feet. To this point the filling 
was composed of mud. Above this distance the deposit was mostly sand. 
Considering the total volume of water which must have passed through 
the reservoir during the four years, the percentage of silt deposited seems 
very small, and the result is not such as to discourage the construction of 
reservoirs on streams where the ratio between run-off and storage capacity 
is less disproportionate. There are no definite data availal)le of the total 
discharge of the river, but assuming it to have been about 50 acre-feet 
annually per square mile of watershed, which is a reasonable assumption 
for streams of that class (the run-off of New York and New England 
streams is from 700 to 2000 acre-feet per square mile, while that of the 
Eio Grande and Gila rivers is 25 to 35 acre-feet per square mile), the total 
volume of water discharged in the four years must have been approximately 
8,000,000 acre-feet, or about 160 times the reservoir capacity. The rela- 
tion of the silt deposited to total run-off would be in the ratio of about 
one-fourth of one per cent of this volume, or 2770 cubic feet per million. 
The river Po,* as determined by M. Tadini, carried as the mean of four 
months 3333 cubic feet per million: the river Ganges, 980 as the mean of 
12 months, and in flood 12,300; the Mississippi, 291 to 1893; the river 
Indus, in flood 2100. A stream of the size and character of the Colorado 
Biver of Texas, to be utilized for irrigation should have a reservoir of 
one to two million acre-feet capacity, to be in proper proportion to the 
volume of run-off and amount of silt carried, and maintain a sufficiently 
long period of usefulness to be profitable. Such a reservoir would probably 
not be filled with silt short of 400 to 500 years. 

Failure of the Austin Dam. — On the 7th of April, 1900, a severe flood 
in the Colorado River and its tributaries, unprecedented since the erection 
of the dam, resulted in the failure of this fine structure, with considerable 
loss of life. About 500 feet of the masonry was first pushed bodily down- 
stream, about 60 feet', apparently sliding on its base, and after a few hours 
was entirely broken up and washed away, with the exception of a small 
section, which still stands upright in the position where it was first de- 

* See Humphrey and Abbott's report on Mississippi Delta Survey, 1878. 

—Austin Dam. Texas. View 

Pio. laSc— Austin Dam, Texas, aftkb Subsidence of Fumd of Apbil 7, 1900. 
Sliowlng sectlou of mnsoiir)- tnoTed bodily donu-Blreain. 

MA80NRT DAMS. 261 

posited. Measured along the crest, the break left about 500 feet of the 
dam at the west end and 83 feet at the east end still unaffected. About 
two-thirds of the wall of the power-house below the dam next the river 
was also destroyed by the flood. The entire property loss must have ex- 
-ceeded $500,000. At the time of the break the lake-level had reached a 
height of 11.07 feet above the crest. The flood was the result of extraor- 
dinary rains throughout a very extensive watershed area. In fifteen hours 
the rainfall at Austin and vicinity was 5 inches, falling on ground already 
well soaked by previous rains. The maximum flood prior to the catastrophe 
occurred June 7, 1899, when the water rose to 9.8 feet above the crest of 
the dam, without injury to the structure. The dam will probably be rebuilt 
upon safer plans, and precautions taken to anchor it into bed-rock a suf- 
ficient depth to prevent it from sliding on its foundations. 

The appearance of the dam immediately before the break is shown in 
Fig. 123a. Figs. 123& and 123c graphically present the break and the 
bodily movement of a section of the dam down-stream intact, better than 
any detailed description. The author is indebted to Engineering News for 
these three cuts. 

Mexican Bams. — By courtesy of Modem Mexico, of St. Louis, Mo., the 
accompanying views of two notable masonry dams at Guanajuato, Mexico, 
are incorporated in this work, as types of reservoir construction in our 
neighboring republic. Fig. 124 shows the upper dam, from which water 
is supplied to the higher portion of the city, through a stand-pipe that is 
shown in the view of the lower dam, or the " Presa de la 011a," Fig. 125 

The upper dam is evidently a massive, ornate structure that would do 
credit to any country of the world, as far as exterior appearances can 
lead one to judge, although the precise dimensions are unfortunately lack- 
ing. Estimating from the proportions of the figures in the foreground, 
the height of the dam must be at least 80 feet. 

The view of the lower dam was taken on St. John's Day, the 24th of 
June, which is celebrated annually by a function called the " Fiesta de la 
Presa," or the feast-day of the dam. 

Sharply at 12 o'clock, noon, of that day, the people congregate to 
witness the opening of the gates, bringing refreshments and musical in- 
struments for a picnic, and thus commences a fortnight of gayety, 
gambling, bull-fights, cock-fights, theater, and dancing. The object of 
letting out the water is to clear the reservoir preparatory to the advent 
of the rainy season, which usually begins about that day. 

The water thus released washes out the river-bed below, which is the 
main drainage of the city. 


Foreign Dams. 

The following descriptions of the principal masonry dams of the world 
outside of the United States have been condensed from the valuable work 
on "The Design and Construction of Dams," by Edward Wegmann, 
M. Am. Soc. C. E., published in 1899. 

The Almanza Dam, Spain. — The oldest existing masonry dam was 
erected in the Spanish province of Albacete prior to 1586. It is built of 
rubble masonry, faced with cut stone, and is 67.8 feet high, 33.7 feet thick 
at base, and of the same thickness for 23.5 feet of its height, the upper side 
being vertical, and the lower face stepped. The crest is 9.84 feet thick. 
The lower 48 feet is built on curved plan with radius of 86 feet. The 
upper portion is irregular. The maximum pressure upon the masonry is 
14.33 tons per square foot. 

The Alicante Bam, Spain. — This structure, erected in a narrow gorge 
on the river Monegre, in 1579 to 1594, is the highest dam in Spain, and 
is used for irrigation of the plains of Alicante. The height is 134.5 feet, 
the base width being 110.5 feet, and the crest 65.6 feet. The gorge 
is remarkably narrow, being but 30 feet at bottom and 190 feet at the top 
of the dam. The dam is curved in plan, with a radius of 351.37 feet on the 
up-stream face at crest, which has a batter of 3 to 41. The dam is built 
of rubble masonry, faced with cut stone. It is supposed to have been 
designed by Herreras, the famous architect of the Escurial palace. 

The reservoir formed by the dam is small for so large a structure, 
having a length of but 5900 feet and a capacity of 975,000,000 gallons 
(2982 acre-feet). 

The stream carries such a large volume of silt that it is necessary to 
scour out the sediment by a device called a scouring-gallery. The scouring 
is done every four years. The gallery is a culvert through the center of the 
dam at the bottom, 5.9 feet wide, 8.86 feet high at the upper end, and en- 
larged below. The mouth is closed by a timber bulkhead, which is cut out 
from below when the scouring is to be done. The sediment forms to a 
great depth above the mouth of the culvert, and has to be started to move 
by punching a hole through it with a heavy iron bar. The total cost of 
scouring the reservoir amounts to $50. The sediment which is not swept 
out by the velocity of the current is shoveled into the stream by workmen. 

The Elche Dam, Spain. — This structure has a maximum height of 76.1 
feet and a base of 39.4 feet, and is formed in three parts, closinsf converging 
valleys. The principal wall is 230 feet long and built of rubble faced with 
cut stone. It is curved in plan, up-stream, with a radius of 205.38 feet. 
It is provided with a scoureins^-sluice similar to that at the Alicnnto rlam, 
but so designed as to be safer for the workmen who remove the timbers 

MA80NRT DAMS. 253 

forming the bulkhead at the mouth of the sluice. The dam is located near 
the town of Elche, on the Kio Vinolapo. 

The Fuentes Dam^ Spain. — This structure is noted because it was of 
unusual height and massiveness^ and yet failed by reason of its having 
been founded on piles driven into a bed of alluvial soil and sand instead 
of bed-rock. It was erected in 1785 to 1791, on the Guadalantin Kiver, 
at the junction of three tributary streams, and stood successfully for eleven 
years, during which time the depth of water never exceeded 82 feet, but 
in 1802 a flood occurred which accumulated a depth of 154 feet in the 
reservoir, and produced suflBcient pressure to force water through the -> 

earth foundation. The reservoir was emptied in an hour, the plpb founda- 
tion was washed out, and a breach in the masonry, 56 feet wide, 108 feet /' ^* 
high, was created, destroying the dam and leaving a bridge arching over 
the cavity. The extreme height of the dam was 164 feet, and its crest 
length was 925 feet; its thickness at base was 145.3 feet, and- at top 35.72 
feet. The extreme pressure on the masonry was computed by M. Aymard 
at 8.12 tons per square foot. It was built of rubble masonry, with cut-stone . 
facings, and was polygonal in plan, with convexity up-stream. Water was 
taken from it through two culverts, one near the base, and the other 100 
feet from the top. These were 5.4 feet wide, 6.4 feet high, and connected 
with masonry wells having small inlet-openings from the reservoir. A 
scouring-sluice, 22 feet wide, 24.7 feet high, was also provided through the 
dam, divided by a pier into two openings at its mouth to shorten the span 
of the timbers that closed it. At the time of the break the mud deposited 
in the reservoir was 44 feet deep. 

The disaster caused the loss of 608 lives and the destruction of 809 
houses. The property loss was estimated at $1,045,000. 

The dam is reported to have been recently restored, and was doubtless 
extended to bed-rock for its foundation. 

Val de Inflemo Dam, Spain. — This dam is 116.5 feet high, and founded 
on rock. It has an enormous section, the base width being 137 feet. Even 
within 15 feet of the top the thickness of the wall is over 97 feet. It was 
built for irrigation in 1785 to 1791, and is located on one of the branches 
of the Guadalantin River, above the Puentes dam. It is not now in service, 
and the reservoir has entirely filled with sediment. The scouring of the 
silt from the reservoir injured the property below, which led to the aban- 
donment of the structure. 

The scouring-sluice of the dam is 14.8 feet high, 9 to 12.3 feet wide. 

The Nijar Dam, Spain. — This dam has a maximum height of 101.5 feet 
above the bed of the stream, and consists of a massive base of masonry, 
144 feet thick, 70 feet high. On this the dam proper rests, having a base 
thickness of 67.6 feet. The upper face is vertical, and the down-stream 
face is built in high steps. The scouring-sluice, which is an appendage 


of all Spanish dams, is 3.3 feet wide by 7.2 feet high, closed at its upper 
end by a gate operated by a long rod extending to the top of the dam. The 
reservoir capacity formed by the dam is 12,570 acre-feet. 

The Lozoya Dam, Spain. — ^The object of this structure, which was built 
about 1850 across the Bio Lozoya, was not to store water, but simply as a 
diversion-weir to supply a canal leading to the city of Madrid. Its height 
is 105 feet, top length 237.8 feet, and it consists of a wall of cut stone, 
straight in plan, having a thickness of 128 feet at base, backed up partially 
by a sloping bank of gravel. The canal is taken through a tunnel in the 
rock on the right bank, 22.4 feet below the top. A second tunnel, used 
as a scouring-sluice, is placed 7.5 feet lower than the canal, below which 
the reservoir is allowed to fill with sediment. A waste-weir is cut in the 
rock, on the left bank, 11 feet deep, 27.6 feet wide. 

The Villar Dam, Spain. — ^In 1870-78 the Spanish Government con- 
structed a second dam on the Bio Lozoya, to supplement the supply to 
Madrid by storage. The dam is 170 feet high, 547 feet long on top, 154.6 
feet thick at base, 14.75 feet thick at the crest, which is 8.25 feet above 
the spillway level. The dam is modem in design, and has a gravity profile 
with large factor of safety. It is also curved in plan, on a radius of 440 
feet. • It is constructed of rubble masonry throughout, with the exception 
of cut-stone copings. Its cost was about $390,000. The capacity of Ihe 
reservoir formed by it is 13,050 acre-feet. Two scouring-sluices are built 
through the dam and closed by gates that are operated by hydraulic power 
from a central tower. 

The Hijar Dams, Spain. — ^Water is stored for irrigation on the Martin 
Biver, above the city of Hijar, Spain, by means of two masonry dams built 
in 1880. The general dimensions of each of these dams are about alike, 
the height being 141 feet, length 236 feet on top, thickness at base 147 feet, 
and at crest 16.4 feet. The water-face is vertical for 82 feet from the top, 
continuing with a vertical curve to the base. The outer face is in a series 
of steps below a point 29.5 feet from the top, each step being 6.5 
feet high, 4.9 feet wide. Both dams are arched up-stream with a radius of 
210 feet. 

One of the reservoirs has a capacity of 8913 acre-feet, and a watershed 
of 17 square miles; the other impounds 4864 acre-feet, and receives the 
drainage from 92 square miles. 

The Oros-Boifl Dam, France. — ^This structure has been severely criticised 
because of the fact that it would be more stable to resist water-pressure 
applied from the lower side than the upper, and for the reason that it 
has an excess of masonry over what would be required if it were distributed 
in proper form; and yet it has but a small factor of safety, as was proven 
by the fact that it slid down-stream on its base about 2 inches, and was 
t)nly relieved of strains that produced cracks and leaks by the addition 


of nine counterforts, 13 to 37 feet thick, projecting 26 feet from the base. 
The dam was originally built vertical on the down-stream face, and stepped 
on the waterside. Its height above bed is 73.2 feet, extreme height 92.9 
feet; top length 1804.6 feet; thickness at base 45.9 feet, at top 21.32 feet. 
It is founded on argiUaceous rock, rather soft. The dam was built in 
1830-38, on the Brenne River, for feeding the navigable canal of Bour- 

The Chazilly Dam was constructed after the general type of the Gros- 
Bois dam, and on the same profile. It is on the Sabine River, near the city 
of Chazilly, and is 1758.6 feet long, 73.8 feet high, 53 feet thick at base, 
13.4 feet at crest. 

The Zola Dam, designed by the father of the noted novelist, is one of 
the few dams depending solely upon their arched form for their stability. 
It is 119.7 feet high, 48.8 feet thick at base, 19 feet thick at top, and 205 
feet long on the crest, which is surmounted by a parapet 4 feet high. The 
gorge has a width of but 23 feet at the base of the dam. The radius of 
the arch is 158 feet at the crown. The water-face has three steps or offsets 
from the vertical and the profile is quite erratic and irregular. It forms a 
reservoir for supplying the city of Aix with water, and was built about the 
year 1843. It is made of rubble masonry, founded on rock. 

The Fnrens Dam. — Among many engineers this famous dam is recog- 
nized as a model of correct form, profile, and dimensions, whose outlines 
conform closely to what are accepted as certainly safe and well-balanced • 
proportions throughout, even though the volume of material may be 
slightly excessive. It was built by the French Government in 1862 to 1866 
for the purpose of controlling the floods of the Furens River and protecting 
the town of St. Etienne from inundations. 

The dam is 183.7 feet in extreme height on the down-stream side, 170.6 
feet in height on the up-stream side, and carrying a maximum depth of 164 
feet of water. Its base thickness is 165.8 feet, and it is 16.4 feet thick at 
a depth of 21 feet below the top. The crest is 12.4 feet wide, and is used 
as a carriage-road; the top length is 326 feet. The dam was four years in 
building, construction being limited to six months each season, owing to 
the altitude and to the severity of the winter weather. Each year, while 
building, the water was allowed to flow over the top of the finished masonry, 
and when completed no leakage was visible further than a few damp spots 
on the lower side with full reservoir. 

The dam contains 52,300 cubic yards of masonry, and cost $318,000, 
of which the city of St. Etienne paid $190,000 for the privilege of the 
storasre for its domestic supply. The rock used was mica-schist. Notwith- 
standing its safe gravity profile the dam was curved up-stream, with a 
radius of 828 feet for architectural effect. The volume of water stored 
by this great dam, the highest in existence, is comparatively insignificant. 


being but 1297 acre-feet (422,625,000 gallons). M. Graeflf, Chief Engineer 
of the Department of the Loire, and M. Delocre designed the dam, and M. 
Montgolfier was engineer in charge of construction. 

The Temay Dam. — Located on the river Temay, in the province of 
Ardcche, southern France, this dam was erected in 1865 to 1868, for con- 
trolling floods and supplying the neighboring town of Annonay. It is con- 
structed of granite rubble masonry, and is founded on bed-rock of granite. 
The proportion of mortar in the work was 40%. In plan it is curved with 
a radius of 1312 feet, while the profile is a gravity type, resembling that 
of the Furens dam. The extreme height is 119 feet, and bottom thickness 
89.2 feet. The up-stream face is vertical for 58.5 feet, and battered below 
that point. The lower face is chiefly formed in a vertical curve of 147.6 
feet radius, reaching from the water-level to within 30.5 feet of the 
bottom, the slope to the base being tangent to the curve. The center of 
the circular curve is 7.5 feet above the crown of the dam. 

The dam was designed and built by M. Bouvier, Engineer des Fonts et 
Chaussees, under the general direction of J. B. Krantz, Chief Engineer. 
The profile of the dam, however, is considerably lighter than the type 
recommended by M. Krantz in his " Study on Reservoir Walls," which 
form resulted from his adherence to a limiting pressure of 6 kilograms 
per square centimeter (85 lbs. per square inch) upon any portion of the 
masonry, whereas the maximum pressures in the Ternay dam are esti- 
mated to be 9 kilos per square centimeter. M. Krantz comments, how- 
ever, on the Ternay dam as follows: " The reservoir wall of Ternay, which 
was remarkably planned and built by M. Bouvier, has, in my opinion, 
scarcely a defect." 

The capacity of the reservoir back of the dam is 686,766,000 gallons 
(2107 acre-feet). The total cost of the dam was $204,372. 

The Vingeanne Dam, France. — This structure resembles the Ternay in 
height and general form, being 113.8 feet high, 18.1 feet thick at base, 
11.5 feet on top. It is located near the town of Baissey, and was built in 

The Ban Dam, France. — ^Next to the Furens dam in height the reservoir 
wall constructed in 1867 to 1870, near the city of St. Chamond, was built 
upon the same general principles, except that a greater maximum pressure 
was permitted upon the masonry, the computed extreme being 8.18 tons 
per square foot. Its extreme height is 157 feet, length 512 feet, base thick- 
ness 127 feet, top width 16.4 feet. The wall is battered or curved on both 
sides, there being no vertical faces. In plan it is curved convex up-stream. 
It is composed of rubble masonry founded on rock. It is used for the 
supply of the city of St. Chamond, and its cost was $190,000. 

The Vcrdon Dam, France. — ^This structure is not of great height, being 
but 59 feet, but its construction presented great difficulties, owing to the 


volume of water carried by the Verdon River, and the narrow canyon in 
which it was placed. The low-water flow is 350 second-feet, while in floods 
the discharge reaches over 4200 second-feet. The dam had to be founded 
on rock, after excavating 20 feet through gravel and bowlders; and as the 
canyon is but 130 feet wide at the top of the dam and considerably less 
at the water-level, there was little room to do the work and take off the 
constant flow. 

The dam is used for diverting water to a canal, supplying the city of 
Aix and other places in the vicinity. The dam proper is curved up-stream 
with a radius of 108.8 feet, resting on a rectangular base of concrete. The 
masonry consists of rubble with cut-stone facings. The general dimen- 
sions are: 

Length on top 131.3 feet. 

Thickness of base 32.5 " 

Thickness of crest 14.2 " 

Height above river-bed 40.2 " 

Height above foundations 59.0 " 

The concrete foundation has a thickness of 48 feet. This is protected 
from the falling water by an embankment of large blocks of loose stone. 
The maximum depth of overflow was estimated at 16.4 feet. 

The Pas Du Eiot Dam, France. — Subsequent to the construction of the 
Furens dam, a second storage-reservoir for the further supply of the city 
of St. Etienne was built in 1872 to 1878 to the height of 113.2 feet, curved 
in plan, and similar in profile to its greater neighbor. The reservoir formed 
by it has a capacity of 343,380,000 gallons (1054 acre-feet). The cost of the 
dam was $256,000. 

The Cotatay Dam, Ftance. — In 1885 a dam was built on the Cotatay 
brook near the city of St. Etienne to supply the city of Chambon-Fen- 
gerolles. This also is of the Furens type, curved in plan, and of the same 
height as the Pas Du Riot dam — 113.2 feet. 

The Pont Dam, France. — This structure, of granite rubble, founded on 
rock, has a maximum length of 495 feet and an extreme height of 85 feet- 
It is curved in plan, with a radius of 1312.4 feet. The base thickness is 
62 feet, and crest 16.4 feet. The water-face batters 4.2 feet in its total 

On the lower face, from the top down for 62.3 feet, is a vertical curve,, 
whose radius is 98.4 feet. The remaining height has a batter tangent to 
this curve. IN'early 20 feet of the base of the dam is below the river-bed. 
Seven counterforts or buttresses, 16 feet long, 3 feet thick, help sustain 
the dam. The dam was built in 1883 on the Armangon River, 2J miles 
from the city of Semur. 


The Chartrain Dam, France. — The profile of this modem structure, 
built in 1888-92, is one of the most graceful and scientific in design of all 
of the French dams of recent construction. It has a maximum height above 
lowest foundations of about 180 feet, and a base width on top of founda- 
tions of 135 feet, the foundations extending above and below the toes of the 
wall to a total width of 156 feet. 

The dam is located on the river Tache, and was built to store water 
for the supply of the city of Roanne. The reservoir, however, is quite 
small for so high and costly a dam, covering but 54.36 acres in area and 
impounding 3647 acre-feet to a mean depth of 67 feet, or 41% of the 
maximum depth. 

The cost ol the dam was $420,000, or $115.10 per acre-foot of storage 

The BoTuey Dam, France. — The failure of this structure April 27, 1895, 
with the loss of one hundred and fiftv lives and the destruction of much 
property, has particularly emphasized the value of several features of 
masonry dams which may be regarded as essential in the design of all 
such works: 

1st. That they be founded on impermeable bed-rock, and the possi- 
bility of upward pressure from water passing through fissures be avoided. 

2d. That they shall have a profile of such dimensions as to permit of 
no tension in the masonry. 

3d. That the masonry shall be practically impervious to water. 

4th. That it be curved in plan to avoid temperature cracks and move- 
ments as the result of expansion and contraction of the masonry. 

The Bousey was lacking in all of these essential features, and its failure 
was not surprising in the light of all the facts that have been published 
regarding it. 

It was built in 1878 to 1881, near Epinal, France, across the small 
stream of Aviere to form a storage-reservoir of 1,875,000,000 gallons for 
supplying the summit level of the Eastern Canal, which here crosses the 
A^osges Mountains in connecting the rivers Moselle and Saone, this canal 
being a connecting link in interior navigation between the Mediterranean 
and the Xorth Sea. The reservoir was fed by an aqueduct from the 
Moselle River. The reservoir covered an area of 247 acres. The general 
dimensions of the dam are as follows: 

Length on top 1700 feet. 

Height above river-bed 49 " 

Heifirht above foundations 72 " 

Width on top 13 « 

Width 36 feet below water-level 18 ^ 


The wall was vertical on the water-face from top to bottom. 

The masonry was founded on red sandstone, which in places was 
fissured and quite permeable, with springs which gave trouble in construct- 
ing the foundations. The foundation was not excavated to solid, im- 
permeable rock under the entire dam, but an attempt was made to remedy 
this deficiency by building what was called a '* guard-walV^ 6.5 feet thick 
on the upper side of the dam,, extending down below the foundations 
through the imperfect rock for the purpose of cutting off leakage under- 
neath. This was carried up to the river-bed and lapped against the main 
wall. The dam was completed in 1880, and the- following year water was 
admitted. When it had reached about one-third the height, 33 feet below 
the top, enormous leakage, amounting it is said to 2 cubic feet per second, 
appeared on the lower side of the dam, partly due to two vertical fissures 
or expansion-cracks in the wall. March 14, 1884, when the water had risen 
to within 10.4 feet of the top, the pressure was sufficient to bulge the 
wall forward for 444 feet, forming a curve convex down-stream, the ex- 
treme movement being from 1 to 3 feet according to different authorities. 
Four additional fissures then appeared, and the leakage increased to about 
8,000,000 gallons per day. These cracks opened in winter and closed in 
summer. The water was kept behind the dam and the following year 
allowed to rise to within 2 feet of the top, after which it was drawn off, 
when it was discovered that for 97 feet the dam had been shoved forward, 
separating from the guard-wall, and numerous cracks were found on the 
inner face. Extensive repairs were then undertaken. The joint between 
the main wall and the guard-wall was covered with masonry and sur- 
rounded by a bank of puddle, 10 feet thick, while a heavy, inclined buttress- 
wall was built at the lower toe, deep into the bed-rock, and toothed into 
the masonry of the dam to prevent the tendency to slide on its base. This 
abutment was nearly 20 feet in height, and its base was 84.3 feet below the 
top of the dam, making the total thickness of base 71.6 feet. Notwith- 
standing all this work the dam was fatally weak at a point near the river- 
bed level, where the line of resistance falls considerably outside the middle 
third, and the final break occurred at a point about 33 feet below the top, 
where the fracture was almost horizontal longitudinally, and 694 feet of 
the central part of the dam was overturned. The break was level trans- 
versely for about 12 feet and then dipped toward the outer face. The 
repairs finished in 1889 were presumed to have made the dam safe, and 
the break did not occur for six years afterwards, during which time the 
action of temperature-changes is presumed to have produced the weak- 
ness resulting in the final catastrophe. An interesting account of the fail- 
ure of the dam was published in Engineering News, May 16 and 23, 1895. 
The lesson taught by it will be serviceable to engineers the world over. 

The Konche Dam,. France. — ^The purpose of this structure, completed 


in 1890, is similar to that of the Bousey dam — to form a storage-reservoir 
for feeding a navigable canal. It is located on the Mouche Kiver, near the 
village of St. Ciergues, and forms a reservoir of 241.8 acres, having a mean 
depth of 29 feet and impounding 7010 acre-feet. The general dimensions 
are as follows: 

Length on top 1346 feet. 

Maximum height, lowest foundation to parapet. 114.5 " 

Height, base to water-line 94.5 ^' 

Width of base Q%,1 '' 

Width of top 11.6 " 

The up-stream face has a batter of 1 foot in 50, while the down-stream 
batter is nearly 1 to 1. 

The dam is straight in plan and carries a roadway over the top, nearly 
25 feet wide, supported by arches resting on abutment-piers that give the 
required extra width. There are forty of these arches, each with a span 
of 26.2 feet. 

The masonry was found experimentally to weigh 134.2 lbs. per cubic 
foot, and the computations of the profile were made on that basis, pre- 
serving the lines of pressure, reservoir full and empty, well within the 
center third. 

The excavations for foundation were required to be so deep to reach 
bed-rock that 56% of the masonry is laid below the surface, the maximum 
depth of excavation being about 40 feet. The water-face of the dam was 
given three coats of hot pitch, and subsequently whitewashed. 

The Oileppe Dam, Belgium. — Xo masonry structure of modern times 
has so great a section as this, and few if any contain such an enormous 
mass of masonry, the total volume of which is 325,000 cubic yards, all of 
which was put in place in six years, from 1870 to 1875 inclusive. The 
dam is most imposing in appearance, but it has a vast excess of masonry 
beyond safe requirements, the effect of which is to place additional stress 
upon the foundation masonry without increasing the stability. The prin- 
cipal dimensions are as follows: 

Maximum height 154 feet. 

Length on top 771 

Breadth on top 49 

Breadth at base 216.5 " 

The dam is curved up-slream on a radius of 1640 feet. It was designed 
by M. Bidaut, Chief Engineer, who occupied nine years in the preliminary 


studies before plans were submitted to the Belgian Government, by whom 
it was erected to regulate the flow of the Gileppe Elver and provide a pure- 
water supply for the cloth manufactories at the city of Verviers. 

The reservoir formed by the dam covers an area of 198 acres and im- 
pounds 3,170,000,000 gallons, or 9730 acre-feet. The mean depth is 49 
feet, or just one-third the maximum depth. The capacity of the reservoir 
is about one-half the average annual run-off from 15.4 square miles of 

The masonry is rough rubble throughout, of sandstone quarried on the 
spot. The dam is surmounted by a cyclopean statue of a lion sitting on 
a pedestal. An ample carriageway is provided across the dam. 

Considering the great thickness of the wall and the care taken in its 
construction, it was a great disappointment to find on filling the reservoir 
that it leaked quite considerably. This leakage gradually diminished and is 
of no importance as affecting the stability of the dam. 

The entire cost of the dam was $874,000, or $89.83 per acre-foot of 
storage capacity. 

The Remscheid Dam, Germany. — This structure is one of the best 
existing types of reservoir-walls as they are designed and built by modem 
German engineers, and possesses more than ordinary interest. It is 82 
feet high, 49.2 feet thick at base, 13.1 feet thick at crown, and is curved 
in plan, with a radius of 410 feet. The total contents of the dam are 22,886 
cubic yards, and its cost is given at $91,154, an average of $3.98 per cubic 
yard. The reservoir formed by it has a capacity of 35,310,500 cubic feet, 
of 811 acre-feet; while its average cost was $112.45 per acre-foot of stor- 
age capacity. 

The dam is built across the Eschbach valley, and is designed to supply 
the city of Remscheid, and manufacturers in the valley below. It was 
begun in May, 1889, and water turned on November, 1892. It is composed 
of rubble masonry, the stone, a hard slate, being laid in trass mortar. Trass 
is a rock of volcanic origin, from which hydraulic lime is made resembling 
pozzuolana, used so extensively in Italy. The mortar consists of one part 
lime, one and one-half parts trass, and one part sand, and was preferred 
by the engineer to Portland cement, because it sets more slowly and tests 
showed it to be superior in point of elasticity. The dam has shown no 
settlement, no cracks, and no leaks. The courses of masonry were laid 
so as to be as nearly perpendicular as possible to the varying direction of 
the resultant pressures at all points. The water-face of the dam was 
plastered with cement mortar, over which two coats of asphalt were placed, 
the asphalt extending 20 inches over the bed-rock. Then a brick 
wall, 1^ to 2i bricks thick, was carried up outside, tight against the 

The dam was designed and built by Prof. 0. Intze, and described in a 


paper published in the Journal of the Society of Oerman Engineers^ from 
which the facts above given are gleaned. 

The Einsiedel Dam, Germany. — This dam was completed in 1894:^ and 
forms a reservoir for supplying the city of Chemnitz. It is composed of 
rubble masonry, the total volume of which was 31,600 cubic yards. Its 
maximum height above foimdation is 92 feet, of which 65 feet is above 
the natural surface. The length over top is 590 feet, top thickness 13 feet, 
base 65.5 feet. It is curved to a radius of 1310 feet. The storage capacity 
of the reservoir is 95,000,000 gallons (291 acre-feet). 

The Oorzente Dam, Italy. — The city of Genoa derives a water-supply 
from a reservoir formed by a masonry dam, built in 1882, on the Gorzente 
Eiver. The reservoir capacity is 748,800,000 gallons (2298 acre-feet), 
covering 64 acres. The dam has a maximum height of 121.4 feet, and is 
492 feet long on top, 23 feet thick at top, 99.6 feet thick at base. The 
masonry is a rubble composed of serpentine rock and mortar of Casale lime 
and serpentine sand. 

Cagliari Dam, Italy. — This structure is located on the island of Sar- 
dinia, 13 miles from the city of Cagliari, on the Corrungius River. It was 
built in 1866, and is 70.5 feet high, 52.5 feet thick at base, 16.4 feet at 
top, and 344.5 feet long on top. It is built of rubble masonry composed 
of granite and a hydraulic lime mortar, mixed with clean, well-washed, 
granitic sand. » 

The Vyrnwy Dam, Wales. — Since July 14, 1892, the city of Liverpool, 
England, has been chiefly supplied by water from a large storage-reservoir 
in the mountains of Wales, 77 miles distant, formed by a monumental dam 
of masonry erected across the Vyrnwy valley, in 1882 to 1889. The dam 
has a top length of 1172 feet, is straight in plan, and has a maximum height 
of 161 feet from foundation to parapet. It is used as an overflow-weir over 
its entire length, and its profile was designed to offer additional resistance 
over that presented by water-pressure alone. An elevated roadway is 
carried across the dam on piers and arches, above the level of flood-water, 
which adds greatly to the architectural effect and ornamentation of the 
imposing mass of masonry. The great wall is composed of cut stone. The 
base width of the dam is 117.75 feet. The back-water level below the 
dam is 45 feet above its base. 

The total volume of masonry in the dam is 260,000 cubic yards, which 
was laid with such extraordinary care that its average cost was nearly $10 
per cubic yard, in a country where materials and labor are of the cheapest. 

The base of the dam is founded on a hard slate rock, and one end of 
the masonry is built into the solid wall of bed-rock on the side of the 
valley. At the other end, however, the rock was so deeply overlaid with 
a deposit of bowlder clay that the masonry was connected with this material 
by a puddle-wall of clay recessed into the masonry. 


The general dimensions of the dam are as follows: 

Total length on top 1172 feet. 

Maximum height on top of roadway parapet 161 " 

Height, river-bed to parapet 101 

Height, river-bed to overflow-level 84 " 

Greatest width of base 120 

Batter of water-face 1 to 7.27 " 

The cost of the dam is given as follows: 

Borings and preliminary work $34,600 

Excavating 220,820 cu. yds. and backfilling 79,501 cu. yds 287,600 

Puddle-wall, including excavation 16,800 

Masonry and brickwork 2,532,000 

Begulating and gauging plant 46,000 

Basin and other work below dam 40,000 

Total for dam proper $2,957,000 

In addition to this the removal of a village in the basin, the building 
of roads around the lake, culverts, fencing, planting, dressing slopes, and 
erection of superintendent's house cost $377,000, or a total of $3,334,000. 

The reservoir formed by the dam covers a surface area of 1121 acres, 
and impounds 12,131,000,000 Imperial gallons, or 44,690 acre-feet. This 
gives a mean depth of 39.87 feet, or 47.5% of the maximum. The water- 
shed area is 29 square miles, upon which the minimum recorded rainfall 
is 49.63 inches, and the maximum 118.51 inches. 

The average cost of the dam per acre-foot of storage capacity formed 
by it was $74.61. 

The dam was planned and constructed by Geo. F. Deacon, Chief 
Engineer, Liverpool Water-works. Messrs. Thos. Hawkesley and J. F. 
Bateman were consulting engineers. 

Tests made by Kirkaldy of large blocks of the concrete and masonry 
taken from the dam showed a compressive strength of 300 tons per square 
foot, while the maximum strains to be borne by it are but 9 tons per square 
foot, an excess of strength which has been considerably criticised. 

The Hi^bra Dam, Algiers. — The French Government has built, or en- 
couraged the construction by private parties of, a number of notable stor- 
ac^e-reservoirs for irrigation in Algiers, of which the largest was that 
formed on the Habra River, by a masonry dam, whose disastrous failure 
has made it well known among the engineering profession, and added to 
the many lessons which such failures carry with them. The dam was 


begun in November, 1865, completed in May, 1873, and after eight years 
of service was ruptured in December, 1881, causing the loss of 209 lives 
and the destruction of several villages. 

The main dam was straight in plan and 1066 feet long on top, flanked 
by an overflow wall, 410 feet long, making an angle of 35** with the direc- 
tion of the dam, the top of which was 5.2 feet below the crest of the dam 

The maximum height of the dam was 117 feet from foundation to the 
water-line, above which a parapet extended 8 feet higher. The dam was 
14 feet thick at top, 88.4 at base, battered on both sides and of ample 
dimensions to withstand the water-pressure, provided the masonry had 
been properly constructed and of first-class material. When completed and 
first filled the dam leaked like a gigantic filter, but the leakage practically 
ceased in course of time. 

The reservoir formed by the dam had a capacity of thirty million cubic 
meters, or 24,330 acre-feet. The watershed of the Habra Biver is very 
extensive, covering 3859 square miles above the dam, from which the 
annual discharge, however, was only about 3J times the capacity of the 
reservoir, owing to the slight rainfall of that region. The summer fiow 
was about 18 second-feet, and the normal winter flow was about 100 second- 
feet, while extreme floods reached 25,000 second-feet in volume. The 
flood which caused the rupture of the dam came from a rainfall of 6^ 
inches in one short storm, during which the run-off in one night was 
computed at 3,500,000,000 cubic feet, or more than three times the reser- 
voir capacity. This resulted in a general overflow of the crest of the wall, 
as the spillway was of insufficient capacity, and produced such excessive 
pressure upon the outer face of the masonry as to exceed its normal 
strength. Over 300 feet of the wall was torn out to the very foundation. 

In a paper on the subject written the following year by the eminent 
Italian engineer, G. Crugnola, he attributes the failure to inferiority in the 
quality of the masonry. The sand was not of good quality, and in the cen- 
ter of the dam a red earth, containing 22 to 24 per cent of clay, was used 
instead of sand. Furthermore, the mortar was made of hydraulic lime 
burned from calcareous rock found on the banks of the river, which, though 
hydraulic, was not very good. The inference drawn by AI. Crugnola is that 
the hydraulic lime contained a quantity of quicklime, which expanded in 
time, causing porosity if not actual cavities in the interior of the masonry. 
The stone, as well as the mortar, was extremely porous, consisting chiefly 
of calcareous Tertiary grit, which was of variable hardness, some having a 
decided schistose structure. 

One must conclude from all the facts that had the spillway been suf- 
ficient in capacity to avoid the submersion of the dam, and had the face 

MA80NBT DAMS. 265 

of the wall been made absolutely water-tight by 8uch precautionary meas- 
ures as were employed on the Bemscheid dam, the failure would not have 
occurred. The curvature of a wall of the great length of the Habra would 
doubtless have avoided temperature cracks, which, as has been pointed 
out by Prof. Forchheimer (page 122), may have been a leading source of 
weakness. The failure occurred during the coldest weather, when such 
cracks appear in masonry walls. 

The Hamiz Dam, Algiers. — Next in importance to the Habra dam, and 
somewhat higher, is the Hamiz dam, erected in 1885 on the Hamiz Kiver. 
This wall is also straight in plan, but only 532 feet in length on top, 131 
feet long at base. The extreme height above foundation is 134.5 feet, and 
above river-bed 91.2 feet, and at top 16.4 feet. Both faces are curved in 

The dam impounds 10,500 acre-feet of water, gathered from a shed of 
54 square miles. 

The Oran Chenrfas Dam, Algiers. — This structure is quite similar in 
dimensions to the Hamiz dam, and was built in 1882-84, on the Mekerra 
Eiver, 9 miles from St. Dionigi. Its foundation extends 32.8 feet below the 
river-bed, and has a thickness of 134.5 feet at base and 78.7 feet at top. 
On this foundation the dam proper rests, with an offset of 3J feet on each 
side, making its thickness at bottom 72 feet, while at top the wall is 13 feet 
thick. Both faces are curved in parabolic form, presenting a graceful 
profile. The maximum pressures on the masonry are 6.1 tons per square 

The dam failed in part when first filled, and a breach of 130 feet was 
made in the wall, but it was immediately repaired. The failure occurred in 
winter. The dam is straight in plan. 

The reservoir capacity behind the dam is about 13,000 acre-feet. 

The Tlelat Dam, Algiers.— This masonry wall is 69 feet high, 325 feet 
long, 40 feet thick at bottom, 13 feet thick at top, and impounds 445 acre- 
feet, derived from a water-shed of 51 square miles. The dam was erected 
in 1869 on the Tlelat River to supply the town of Sante Barbe, 7^ miles 
below, and also for irrigation. The wall is vertical on the water-face, while 
the lower side has a vertical curve, the center of radius being 11.8 feet 
above the top of the dam. 

The Djidionia Dam, Alg^iers, is 83.7 feet in extreme height, of which 
28 feet is foundation below the river-bed level. The face is vertical, and 
the dam is straight in plan. The foundation is broader on top than the 
bottom of the dam, and will permit of an increased height in the structure 
by adding to the lower side from the foundation up. This has been de- 
cided upon, and 26 feet additional in height will be built. The reservoir 
will then have a capacity of about 4000 acre-feet. The dam was built in 


1873-75, on the Djidionia River, to supply the towns of St. Aim6 and 
Amadema with water. The masonry of this dam is slightly in tension on 
the water-face when the reservoir is filled, amounting to about 15 lbs. per 
square inch, but no injurious effect upon the masonry is apparent from 
this small tensile strain. 

The Tansa Dam, India.* — This great dam, forming a reservoir for the 
supply of Bombay, was begun in 1886, and completed in April, 1891. The 
work was done by contract and cost $988,000. It is straight in plan, the 
alignment consisting of two tangents, and it has a total length of 8800 
feet, the maximum height being 118 feet. For a length of 1650 feet the 
dam is depressed 3 feet, to serve as a waste-weir. The thickness of the 
masonry at the base is 96.5 feet, and the entire section is made of sufficient 
dimensions for an ultimate height of 135 feet, to which it may be raised 
in future, when its length will be 9350 feet on top. 

The dam was built with native labor, and consists of uncoursed rubble 
masonry throughout, all the stones being small enough to be carried by 
two men. The stone is a hard trap-rock, quarried on the spot. The 
cement was burned at the site of the dam from nodules of hydraulic lime- 
stone, called kunkur, which are found throughout India, and occur in clay 
deposits, although in this case it had to be brought long distances by rail 
and carts. Most Indian masonry is made with kunkur hydraulic lime. 
The nodules require to be exposed to the sun, dried and washed before 
being burned. They are usually of one or two pounds weight, although 
sometimes found in blocks of 100 lbs. or more. 

From 9000 to 12,000 men were employed on this dam during the work- 
ing season of each year, from May to October, but during the monsoons all 
work was suspended. 

The volume of masonry in the work is 408,520 cubic yards. It ia 
reported to be entirely water-tight. The excavation was carried to a 
considerable depth in places, and necessitated the removal of 251,127 cubic 
yards for the foundations. 

The reservoir covers an area of 5120 acres and impounds 62,670 acre- 
feet above the level of the outlets, which are placed 25 feet below the crest 
of the spillway, or 89 feet above the river-bed. The loss by evaporation 
reduces the available supply to 15,870 acre-feet, although, of course many 
times this quantity could be drawn from the lake if the outlets were near 
the bottom. The watershed area is 52.5 square miles, on which the precipi- 
tation is from 150 to 200 inches annually, and the estimated annual run- 
off is 267,000 acre-feet. 

* See Procepdinfirs Institution of Civil Engineera, vol. cxv. Pap^r by W J. C. 
Clerke, M.I.C.E.. on **The Tansa Works for tlio Water-supply of Bombay"; also, 
•' Irri^tion in India," by Herbert M. Wilson, 12tb Annual Report U. 8. Geological 


The dam was planned and built by W. J. C. Gierke, Chief Engineer. 

The Foona or Lake Fife Dam, India.* — This was one of the first 
masonry dams built in India by the British Government for irrigation 
storage, and was begun in 1868. It is made of uncoursed rubble masonry, 
founded on solid bed-rock, and is straight in plan, having a top length of 
5136 feet (nearly a mile), of which 1453 feet is utilized as a wasteway. 
Its maximum height above foundation is 108 feet, and above the river-level 
98 feet. 

The design of the dam is extremely amateurish. The up-stream batter 
is 1 in 20, and the down-stream slope 1 in 2, unchanged from top to bottom, 
the top width being 14 feet, and the base 61 feet. The alignment of the 
dam is in several tangents with different top width for each, according to 
its height, the points of junction being backed up by heavy buttresses of 
masonry. When completed the dam showed signs of weakness and was 
strengthened by an embankment of earth, 60 feet wide on top, 30 feet 
high, piled up against the lower side. 

The water is drawn from the reservoir 59 feet above the river-bed, 
and there is therefore available but 29 feet of the total depth of the reser- 
voir. The amount available above this level is 75,500 acre-feet. The lake 
is 14 miles long and covers an area of 3681 acres. 

The dam is located 10 miles west of the town of Poona, on the Mutha 
Eiver. Its cost was $630,000, and it contains 360,000 cubic yards of 

The canal on the right bank is 23 feet wide, 8 feet deep, and 99.5 
miles long, drawing 412 second-feet from the reservoir and distributing 
it over 147,000 acres of land to be irrigated. At the town of Poona a 
drop of 2.8 feet is utilized for power by an undershot wheel, to pump 
water to supply the town. The left-bank canal is 14.5 miles long and 
carries 38 second-feet. The sluices from the reservoir are each 2 feet 
square, closed by iron gates operated by capstan and screw from the top 
of the dam. Ten of these supply the larger canal, and three discharge 
into the smaller one. Eight additional circular sluices, 30 inches in 
diameter, supply water to natives for mill-power and discharge into the 
larger canal. 

The Bhatgur Dam, India.f — There are no masonry structures in the 
United States or Europe which surpass in size those of India which have 
been constructed for irrigation purposes by the British Government, in 
the attempt to render the great population of that country self-supporting 

 "Irrigation in India," by H. M. Wilson, in 12th Annual Report IT. 8. Geological 
t Ibid, 


and check the frightful famines by which it has been periodically devas- 

The Bhatgur dam, constructed on the Yelwand River, about 40 miles 
south of Poona, is one of the most notable of these great structures. Its 
length on top is 4067 feet, its extreme height above foundations is 127 
feet, and it forms a reservoir 15 miles in length, having a capacity of 
126,500 acre-feet The extreme bottom width of the dam is 74 feet, and 
the crest is 12 feet wide, forming a roadway. The alignment of the dam 
curves in an irregular way across the valley, so as to follow the outcrop of 
bed-rock on which it is founded. The section of the dam was designed 
after a formula similar to that deduced by M. Bouvier, and all the calcula- 
tions were worked out by Mr. A. Hill, M.I.C.E., who was afterwards 
assistant on the construction of the Tansa dam. The curve adopted for 
the lower face was a catenary, but the wall was actually built in a series 
of batters. 

The three primary conditions of the design were: 

1st. The intensity of the vertical pressure was nowhere to exceed 120 
lbs. per square inch (8.64 tons per square foot); 

2d. The resultant pressures were to fall within the middle third of the 
section; and 

3d. The average weight of the masonry was assumed at 160 lbs. per 
cubic foot. The use of concrete was only permitted where the pressure 
was calculated not to exceed 60 lbs. per square inch, which gave a factor 
of safety of between 6 and 7. 

The dam was designed and built by J. E. Whiting, M.I.C.E. 

Waste-weirs at each end of the dam have a total length of 810 feet, 
and can carry 8 feet depth of water. The roadway is carried over these 
weirs on a series of 10-foot arches. Additional flood-discharge is given 
by twenty under-sluices, 4x8 feet in size (of which fifteen are located 60 
feet below the crest), having a total capacity of 20,000 second-feet. These 
sluices are lined with cut stone, and closed by iron gates, operated from 
the top of the dam. The overflow wasteway is closed by a novel series of 
automatic gates that open in flood and rise up into position as the flood 
recedes, permitting the full storage of the additional 8 feet depth to be 
utilized. The gates are. nicely balanced by counterweights that occupy 
pockets in the masonry. As the water rises to the top of the gate it fills 
these pockets, reducing the weight of the counterpoises, and the gate, being 
then heavier, will descend below the crest of the weir. When the level of 
the flood is reduced so that it no longer enters the pockets, the latter are 
emptied by small holes in the bottom, and the counterpoises overcome the 
weight of the gates, lifting them into place again. 

The reservoir is used to supply the Nira Canal, which heads 19 miles 
below. This canal is 129 miles long, 23 feet wide, 7.5 feet deep, and carries 


470 second-feet, supplying 300 square miles of land. The water is diverted 
to it b}' a masonry diverting-dam, known as the Vir weir, which is of itself 
an important structure, being 2340 feet long, 43.5 feet high, constructed 
of concrete faced with rubble masonry. Its top width is 9 feet. Maximum 
floods of 158,000 second-feet pass over its crest to a depth of 8 feet, coming 
from a watershed of 700 square miles. A secondary dam, forming a water- 
cushion, is located 2800 feet down-stream. This is 615 feet long, 24 feet 
high, built of masonry founded on bed-rock, and carries a roadway over 
its crest. During maximum floods the water is 32 feet deep in the cushion, 
when the water is 8 feet deep over the main dam. 

The works were finished in 1890-91. 

The Betwa Dam, India.* — This masonry structure forms a diversion- 
weir for turning the water of the Betwa Biver into a large irrigation-canal, 
and also serves for storage to the extent of 36,800 acre-feet, which is the 
capacity of the reservoir above the canal flow, although not all available. 

The total length of the dam is 3296 feet, and its maximum height is 
60 feet. It has an extremely heavy profile, being 15 feet thick at top and 
61.5 feet at base. At its highest part the down-stream face is vertical, and 
a large block of masonry 15 feet thick reinforces the dam at its lower toe. 
It consists of rubble masonry laid in native hydraulic lime, with a coping 
of ashlar, 18 inches thick, laid in Portland-cement mortar. 

In plan the dam is divided into three sections, of different lengths, by 
two islands, and is irregular in alignment. 

The canal floor is placed 21.5 feet below the crest of the dam. A 
masonry subsidiary weir, 12 feet wide on top, 18 feet high, to form a water- 
cushion for the overflow of the dam, was built 1400 feet below, across the 
main channel, and a second subsidiary weir, 200 feet below the main weir, 
was made, to check the right-bank channel at the same level. The main 
dam and subsidiary weirs cost $160,000, not including the regulating and 
flushing sluices, which cost $10,000. The main canal is 19 miles long, and 
with its branches supplies 150,000 acres. 

The Periyar Dam, India. — None of the modem structures for irrigation 
storage in India have presented greater difficulties than the great dam 
erected across the Periyar River, which was begun in 1888 and completed 
in 1897. The project, of which the dam was the basis, includes the con- 
struction of a wall to close the valley of the Periyar River to store 300,000 
acre-feet of water; of the construction of a tunnel 6650 feet long, through 
the mountain-range dividing the valley of the Periyar from that of the 
Vigay River, for the purpose of drawing off the water of the reservoir, 
with the necessary sluices and subsidiary works for controlling the water 
on its way down a tributary of the Vigay; and finally the necessary works 

 See " Irrigation in India," by H. M. Wilson, in 12tb Annual Report^ U. S. Geo- 
logical Snrvey. 


for the diversion, regulation, and distribution of the water for the irriga- 
tion of 140,000 acres in the Vigay valley, of which area the water-supply 
of the Vigay was only sufficient for irrigating 20,000 acres. 

The dam is 155 feet high above the river-bed, with a parapet 5 feet 
higher, the foundations reaching to a depth of 173 feet below the crest. 
It is 12 feet thick at top and 114.7 feet at base, and is constructed through- 
out of concrete composed of 25 parts of hydraulic lime, 30 of sand, and 100 
of broken stone. The water-face is plastered with equal parts of hydraulic 
lime and sand. The length of the dam on top is 1231 feet. Its cubic con- 
tents are about 185,000 cubic yards of masonry. 

A wasteway has been excavated on each side of the dam, one of which 
is 420 feet long, and the other 500 feet long. The latter is partially formed 
by a masonry wall 403 feet long, filling a saddle-gap. The crests of these 
waste ways are 16 feet below the top of the parapet. The rock is a hard 
syenite. The maximum floods of the river reach 120,000 second-feet at 
times. The drainage-area above the dam is 300 square miles, on which 
the rainfall is from 69 to 200 inches, averaging 125 inches per annum. 

The river is one that is subject to violent and sudden floods, in an 
uninhabited tract of country, far even from a village, some 85 miles from 
the nearest railway, where there were no roads or even paths, in the 
midst of a range of hills covered with dense forests and jungles tenanted 
by wild beasts, where malaria of a malignant type is prevalent, where the 
commonest necessaries of life were unobtainable, and where the incessant 
rain for half the year prevented the importation of labor and rendered 
all work in the river-channel impossible for six months out of every 
twelve. During the first two years of construction watchmen with drums 
and blazing fires had to guard every camp at night against the curiosity 
of wild elephants that constantly visited the works, uprooting milestones, 
treading down embankments, breaking up fresh masonry, playing with 
cement-barrels, chewing bags of cement and blacksmith's bellows, kneeling 
on iron buckets, and doing everything that mischief could suggest and 
power perform. 

The limestone for making the hydraulic lime was brought a distance 
of 16 miles, surmounting an elevation of 1300 feet by an endless wire 
rope, 3 miles long, to which the stone was brought by wagon-road. From 
the lower end of the ropeway the stone was carried on a short tramway to 
canal-boats plying on the river as far down as the dam, the stream having 
teen made navigable for this purpose. 

The sand used was dredged from t^e river-bed. 

This brief summary of the unusual conditions under which the dam 
was built, gleaned from a paper written by Mr. A. T. Mackenzie, 
A.M.I.C.E., gives a general idea of the extraordinary^ difficulties which had 
to be overcome in constructing this great work, which is certainly one of 


the most notable of the many monuments to English engineering in 


The total cost of all the works connected with the project amounted 
to about $3,220,000. The estimated net revenues were $260,000 annu- 

The dam was designed and constructed by Col. Pennycuick, Chief 
Engineer. It is so designed (by M. Bouvier's formulae) that the greatest 
pressure on front and back shall not exceed 9 tons per squai^e foot, and 
the lines of pressure are kept within the middle third. Most modern dams 
of any magnitude have been built of uncoursed rubble masonry. Col. 
Pennycuick justifies the use of concrete in the Periyar dam in the follow- 
ing language, as quoted by Mr. Wilson: " Concrete is nothing more than 
uncoursed rubble masonry reduced to its simplest form, and as regards 
resistance to crushing or to percolation the value of the two materials is 
identical, unless it be considered as a point in favor of concrete that it 
must be solid, while rubble may, if the supervision be defective, contain 
void spaces not filled with mortar. The selection depends entirely upon 
their relative cost, the quantities of materials in both being practically 

In this opinion of the value of concrete he is less conservative than 
the engineers of the Tansa dam, who limited the use of concrete to the 
upper portion of the dam, where the limit of pressure did not exceed 60 
lbs. per square inch. 

While the full reservoir capacity is 305,300 acre-feet, the level of the 
outlet-tunnel is such that but 156,400 acre-feet can be utilized, although 
this may be supplied several times annually. 

The Beetaloo Dam, South Australia. — Like the Perivar dam in India 
and the San Mateo dam in California, this structure is composed entirely 
of concrete, of which about 60,000 cubic yards were used. 

The dam was built in 1888-90, to form a reservoir of 2945 acre-feet 
capacity for irrigation and domestic water-supply. 

The dam is 580 feet long on top, curved in plan, with a radius of 
1414 feet, and designed after Prof. Eankine's logarithmic profile type. 
The maximum height is 110 feet, the base width being the same as the 
height. The thickness at top is 14 feet. The spillway is 200 feet long, 
5 feet deep. The cost was $573,300. 

Water is distributed entirely by pipes under pressure, some 255 miles 
of pipe from 2 to 18 inches diameter being required. 

The dam was designed and built by Mr. J. C. B. MoncriefF, M.I.C.E., 
Chief Engineer. 

The Oeelong Dam, Australia. — This structure is also constructed wholly 
of concrete, made of broken sandstone and Portland cement, in the pro- 
portion of 1 of cement to 7^ of aggregates. 


The dam is 60 feet high^ 39 feet thick at base^ and 2.5 feet on crest. 
It is curved in plan on a radius of 300 feet from the water-face at crest. 
The coping is formed of heavy bluestone of large size, cut and set in 
cement. The work was carried up evenly in courses a few inches thick, 
and thoroughly rammed. The surface of the finished concrete was wetted 
and coated with cement grout before adding a fresh layer to it. 

The dam forms a reservoir for the supply of the city of Victoria. Water 
is drawn from it by two 24-inch pipes passing through the masonry, one 
of which is used for scouring purposes. The dam leaked slightly at the 
outset, but this leakage quickly disappeared. 

The Tytam Dam, China. — This modem English structure was built 
to store water for the supply of Hong Kong. It is about 95 feet high, and 
is intended to go 20 feet higher. The present crest width is 21 feet, base 
about 65 feet. The water-face of the wall is almost vertical, the outer face 
being stepped in 10 feet vertical courses. The water-face is laid up in 
granite ashlar, the remainder being concrete, with stones of 2 to 6 cubic 
feet embedded. About 40% of the entire wall is composed of stone, and 
60% of concrete. The screenings of crushed granite were used as sand, 
together with some river sand, which was scarce, and used without wash- 
ing, as it was believed the rock dust and fine particles of soil would con- 
duce to water-tightness. The strength of the mortar was less of a 
consideration than the securing of a water-tight wall 

The Assnan Dam, Egypt. — A dam is under construction at the present 
time across the Upper Nile, in Egypt, by English capitalists and English 
engineers, which in many respects is equal to the boldest and most ex- 
tensive storage works constructed in India. The dam is intended to form 
a reservoir in the Nile valley, whose storage capacity is about 1,031,500 
acre- feet, for the irrigation of a tract of 2500 square miles of land, located 
some 350 miles down the valley of the Nile below the dam. Water 
released from the reservoir travels down the Nile a distance of 330 miles 
to a point called Assiout, where a diverting-dam is being constructed to 
raise the water to the level of the canal. 

The Assuan dam is to be about 6400 feet long, founded on granite 
rock throughout, and having a maximum height of 90 feet above founda- 
tions. The thickness of masonry at base will be about 80.4 feet, and the 
top width 23 feet, the crest being 9.84 feet above the estimated level of 
high water in the reservoir, and carrying a roadway. It is built of granite, 
uncoursed rubble, the stone being quarried from adjoining ledges of red 
syenite The wall will have one hundred and forty culverts or under- 
sluices passing through it, each 23 feet high and 6.56 feet wide, and forty 
upper sluices, having one-half the area of the lower culverts. These are 
to be employed for the passage of extraordinary floods and the scouring 
of silt from the reservoir. All of the upper sluices and twenty of the lower 


ones will be lined with cast iron^ and the remainder with cut-stone ashlar. 
The piers between sluices are 16.4 feet wide, with an abutment-pier at 
every tenth sluice, 39.37 feet wide. 

The maximum floods of the Nile are estimated to discharge 490,000 
second-feet, and a mean maximum of about 350,000 second-feet. 

The sluices will all be opened during floods. The under-sluices will 
be regulated by Stoney's self-balanced gates. A navigation-canal will be 
taken around the west end of the dam, 5250 feet long, having four locks, 
with a total descent of 68.9 feet. This canal will be excavated partly in 
rock and partly formed by an embankment. It will be 49.2 feet wide on 
bottom. The dam and locks are estimated to cost $6,125,000, and are 
being built by English contractors, who agree to complete the work by 
July 1, 1903. 

The dam was designed by Mr. W. Willcocks, M.LC.E., in the service of 
the Egyptian Government. 

The ABsiout Dam, tipper Egjrpt.* — In connection with the utilization 
of water stored in the great Assuan reservoir a diverting-weir is being 
erected across the Nile, below the head of the Ibrahimia Canal, which is 
estimated to cost $2,245,000, including the navigation-canal and locks. 

This dam is also of masonry, and will have a total length of 3930 feet, 
and a maximum height of 48 feet. The dam will have one hundred and 
twenty sluices, each 16.4 feet wide, with piers 6.56 feet wide between them. 
The navigation-lock will be 262 feet long, 52.5 feet wide, capable of 
passing the largest steamers that ply on the Nile. It is located about 200 
miles above Cairo. The head-works of the Ibrahimia Canal will cost 

The loss of water from evaporation and seepage in the Assuan reser- 
voir, and in traversing the distance of 330 miles to Assiout, is estimated at 
about 21.5%, leaving 736,800 acre-feet as the net amount available for 

* See Engineering Beeard, Dec. 80, 1899. 



The earliest constructions for water-storage of which there is historical 
record have been earthen dams erected to impound the water for irrigation. 
India and Ceylon afEord examples of the industry of their inhabitants in 
the creation of storage-reservoirs in the earliest ages of civilization, which 
for number and size are almost inconceivable. Excepting the exaggerated 
dimensions of Lake Moeris in central Egypt, and the mysterious basin of 
" Al Aram," the bursting of whose embankment devastated the Arabian 
city of Mareb, no similar constructions formed by any race, whether ancient 
or modem, exceed in colossal magnitude the stupendous tanks of Ceylon. 
The reservoir of Koh-rud at Ispahan, Persia, the artificial lake of Ajmeer, 
or the tank of Hyder in Mysore, cannot be compared in extent or grandeur 
with the great Ceylonese tanks of Kalaweva or Padavil-colon. The first 
Ceylon tank of which there is historical record was built by King Pandu- 
waasa in the year 504 B.C. The tank of Kalaweva was constructed a.D. 459, 
and was not less than 40 miles in circumference. The dam or embank- 
ment of earth which formed it was more than 12 miles in length, and the 
spillway of stone is described by the historian Tennent as " one of the 
most stupendous monuments of misapplied human labor on the island." 
The same author describes the tank of Padavil as follows: 

" The tank itself is the basin of a broad and shallow valley, formed 
by two lines of low hills, which gradually sink into the plain as they 
approach the sea. The extreme breadth of the enclosed space may be 12 
or 14 miles, narrowing to 11 at the spot where the retaining bund has 
been constructed across the valley. ... The dam is a prodigious work, 11 
miles in length, 30 feet broad at the top, and about 200 feet at the base, 
upwards of 70 feet high, and faced throughout its whole extent by layers 
of squared stone. . . . The existing sluice is remarkable for the ingenuity 
and excellence of its workmanship. It is built of hewn stones varying from 
6 to 12 feet in length, and still exhibiting a sharp edge and ever^^ mark 
of the chisel. These rise into a ponderous wall immediately above the vents 
which regulated the escape of the water; and each layer of the work is 
kept in its place by the frequent insertion, endwise, of long plinths of 



stone, whose extremities project beyond the surface, with a flange to key 
the several courses and prevent them from being forced out of their places. 
The ends of the retaining-stones are carved with elephants' heads and 
other devices, like the extremities of Gothic corbels; and numbers of 
similarly sculptured blocks are lying about in every direction. . . . On 
top of the great embankment itself, and close by the breach, there stands a 
tall sculptured stone with two engraved compartments, the possible record 
of its history, but the characters were in some language no longer under- 
stood by the people. The command of labor must have been extraordinary 
at the time when such a construction was successfully carried out, and the 
population enormous to whose use it was adapted. The number of cubic 
yards in the bund is upwards of 17,000,000, and at the ordinary value of 
labor in this country [England] it must have cost £1,300,000, without 
including the stone facing on the inner side of the bank. The same sum 
of money that would be absorbed in making the embankment of Padavil 
would be sufficient to form an English railway 120 miles long, and its 
completion would occupy 10,000 men for more than five years. Be it 
remembered, too, that in addition to 30 of these immense reservoirs in 
Ceylon, there are from 500 to 700 smaller tanks in ruins, but many still 
in serviceable order, and all susceptible of effectual restoration. . . . None 
of the great reservoirs of Ceylon have attracted so much attention as the 
stupendous work of the Giants' Tank (Kattucarr6). The retaining-bund 
of the reservoir, which is 300 feet broad at the base, can be traced for more 
than 15 miles, and, as the country is level, the area which its waters were 
intended to cover would have been nearly equal to that of Lake Geneva, 
Switzerland (223 square miles). At the present day the bed of the tank 
is the site of ten populous villages, and of eight which are now deserted." 

It was but recently discovered that the reason why the great reservoir 
was never utilized after having been built at such enormous expense, was 
an error in the original levels by which the canal from the Malwatte River, 
that was intended to feed the reservoir, ran up-hill. 

Capt. R. Baird Smith, in his work on "Irrigation in the Madras 
Provinces," says: 

" The extent to which tank irrigation has been developed in the Madras 
Presidency is extraordinary. An imperfect record of the number of tanks 
in fourteen districts shows them to amount to no less than 43,000 in repair ' 
and 10,000 out of repair, or 53,000 in all. It would be a moderate esti- 
mate to fix the length of embankment for each at half a mile, and the • 
number of masonry works in sluices, waste-weirs, etc., would probably not 
be overrated at an average of six. These data, only assumed to give some 
definite idea of the system, would give close upon 30,000 miles of embank- 
ments (sufficient to put a girdle round the globe not less than 6 feet thick) 
and 300,000 separate masonry works. The whole of this gigantic ma- 


chinery is of purely native origin, not one new tank having been made 
by the English. The revenue from existing works is roughly estimated 
at £1,500,000 sterling per annum, and the capital sunk at £15,000,000/' 

The same author described the Ponairy tank of Trichinopoly, now out 
of repair, as having an embankment 30 miles in length, and an area of 
60 or 80 square miles. The Yceranum tank is very ancient, though still 
in service and Yielding a revenue of $57,500 per annum. It has an em- 
l>ankment 12 miles long, and covers 35 square miles of area. 

The Chumbrumbaukum tank has an embankment 19,200 feet in length, 
end forms a reservoir of 5730 acres, with a capacity of 63,780 acre-feet. 
The dam is 16 to 28 feet high. The water from the reservoir yielded an 
annual revenue to the government of $25,000 in 1853. 

The Cauverypauk tank, in use from four hundred to five hundred years, 
has an embankment 3J miles long, revetted with a stone wall 6 feet thick 
at bottom, 3 feet at top, and 22 feet high, rising to within 5 or 6 feet of the 
top of the bank, which is uniformly 9 feet high above high-water mark. 
The embankment is nowhere less than 12 feet wide on top, with a front 
slope of 2^ to 1, and a rear slope of 1^ to 1. The whole outer surface is 
carefully turfed and planted with grass. Water is distributed from nine 
masonrv sluices. 

Mr. H. M. Wilson, in his work on " Irrigation in India," describes the 
abandoned tank of Mudduk Masur as having been built over four hundred 
years ago, when its capacity must have been 870,000 acre-feet of water. 
The restraining-dams were three in number; the main central dam, which 
is 91 to 108 feet high, and having a base of 945 to 1100 feet, is still intact, 
and the whole reservoir is capable of easy restoration. The lack of a spill- 
way caused the destruction of the tank by the overtopping of one of the 
minor embankments. Mr. Wilson states that in the Mysore district of 
southern India there are 37,000 tanks, aside from the 53,000 enumerated 
in the Madras Presidency by Capt. R. Baird Smith. In the Mairwara 
District 2065 tanks have been built under English rule since the date of 
Capt. Smith's work, before quoted — 1854. 

Of the modem earthen dams built by English engineers in the employ 
of the Indian Government, two of the most interesting were recently con- 
structed in the Bombay Presidency, the Ekruk tank near Sholapur, and 
the Ashti tank, on the Ashti River. The Ekruk tank (Fig. 126) impounds 
76,130 acre-feet, and has a dam whose maximum height is 72 feet. The 
total length is 7200 feet, which included 2730 feet of masonry, of which 
1400 feet is at the northern end and 1330 feet at the southern end. The 
cost of the dam was $666,000. The loss of water by evaporation during 
eight months is 7 feet in depth and amounts to 12,500 acre-feet, or 16% 
of the entire capacity. 

The Ashti tank (Fig. 127) is formed by an earth dam 12,709 feet long, 


58 feet in maximxun height^ having slopes of 3 : 1 inside and 2 : 1 outside. 
The crest of the dam is 12 feet above high-water mark, and has a width 
of 6 feet. The interior slope is paved with stone. The storage capacity 
of the reservoir is 32,G60 acre-feet, of which 9200 acre-feet, or 28%, is 
lost by evaporation. The reservoir has a surface area of 2677 acres. The 
following description of the construction of the dam is condensed from 
Mr. H. M. Wilson's "Irrigation in India": 

The site of the dam was cleared of vegetation and top soil, so that 
the entire structure rests upon a sound and firm foundation. There is no 
puddle-wall proper, but a puddle-trench, 10 feet wide, was excavated down 
to a compact, impervious bed, the entire length of the dam, and was filled 
to one foot above the natural ground surface. This filling was composed 
of two parts sand and three parts black soil. The central third of the 
dam is built up of selected material of black soil, extending, as shown in 
the accompanying section, in a triangular section, 60 feet wide at the base, 
to the crest of the dam. Outside of this central section are two triangular 
sections of brown soil, faced with 1 to 15 feet of puddle of sand and black 
soil. On the inside a stone paving 6 inches thick is laid over the slope to 
resist wave-action. Across the river-bed a trench 5 feet wide was excavated 
along the entire length of the dam and extending 100 feet into the banks. 
On each side this trench was filled with concrete and connected with the 
puddle-trench. The puddle-trench was curved around the concrete wall 
and continued across the river at a distance of 20 feet from the concrete 
wall on the up-stream side. This work having been finished in dry weather, 
the sand of tfie river-bed was sluiced out of the way by confining the 
stream and directing it into narrow channels by loose rock spur-walls and 

The cross-section of the Ashti dam is considered amply strong, yet a 
more liberal section is believed to be advisable, especially in the matter 
of top width. 

The wastewav of the Ashti reservoir consists of a channel 800 feet 
wide, cut through the ridge rock, the crest of which is level for '600 feet 
in length; thence the stream falls with a slope of 1% into a side channel. 
Its discharging capacity is 48,000 second-feet, causing the water to rise 
7 feet above its sill, or to within 5 feet of the top of the dam. 

In 1883 a serious slip occurred in the Ashti dam, causing a total settle- 
ment of 16 feet at the crest of the embankment, and causing the ground 
at the top of the dam to bulge upwards. The cause of this slip was 
attributed to the fact that for a considerable portion of the length of the 
dam it is founded on a clay soil containing nodules of impure lime and 
alkali, which render it semi-fluid when soaked with water. The slip 
occurred during or after excessive rains. It was corrected by digging 
drainage-trenches at the rear toe, which were filled with bowlders and ' 


broken stone, and by the addition of heavy berms or counterforts of earth, 
for 700 or 800 feet of its length, to weight the toe. 

Similar slips occurred in the Ekruk dam, due to similar causes. These 
occurrences point to the value of thorough drainage to the outer toe of all 
earthen dams, and the desirability, of the adoption of that form of combina- 
tion of rock-flll and earth used so successfully in the Pecos dams, wherever 
rock can be obtained for the outer portion of such embankments. 

Yallejo Dam, California. — Wherever earthen dams are constructed 
partially upon exposed bed-rock foundations, it is essential to provide free 
drainage to the water which seeks to follow along the bed-rock. An inter- 
esting application of this principle was made in the construction of a dam 
erected a few years since for the water-supply of Vallejo, California. 
The dam was built for storage purposes and formed a reservoir of 160 acres, 
3 miles from the city. The bed-rock was exposed in the channel, and 
formed a low fall about the center line of the dam. Just above this fall 
a concrete wall was built upon the bed-rock some 6 feet high, with a 
drainage-pipe extending out to the lower toe of the embankment. A 
quantity of broken stone was placed above this wall, which formed a 
collecting-basin for any seepage that might pass through the embankment 
or that might creep along bed-rock, and the dam was then built over the 
wall in the ordinary way. This provision efEectually prevents the satura- 
tion of the outer slope and keeps the dam well drained. The dam was 
planned and built by Hubert Vischer, C.E., with Mr. C. E. Grunsky 
acting as Consulting Engineer. 

Earthen dams are usually constructed in one of the following ways: 

(1) A homogeneous embankment of earth, in which all of the material 
is alike throughout; 

(2) An embankment in which there is a central core of puddle con- 
sisting either of specially selected natural materials found on the site, 
or of a concrete of clay, sand, and gravel, mixed together in a pug-mill 
and rammed or rolled into position; 

(3) An embankment in which the central core is a wall of masonry or 

(4) An embankment having puddle or selected material placed upon its 

(5) An embankment of earth resting against an embankment of loose 

(6) An embankment of earth, sand, and gravel, sluiced into position by 
flowini^ water — a form of construction described in the chapter on Hy- 
draulic-fill Dams. Earthen dams have also been built with a facing of 
plank, made water-ti^ht by preparations of asphaltum or tar. The choice 
of these various available plans is dependent upon local conditions at the 
site of the dam to be built, the materials available, and the predilection or 
education of the engineer planning the structure. 


European engineers, judging from their works, lean toward the central 
puddle-core, and the greater number of the earth dams of the British 
Empire are constructed on this plan. American engineers appear to prefer 
the masonry core-wall, or the puddle facing on the inner slope of the 
embankment to the central puddle-core, as a means of cutting oflE per- 
colation through the dam and thus securing water-tightness. 

The natural slope of dry earth placed in embankment is about 1^ to 1, 
but in practice it is customary to increase this to 2 to 1 on the exterior, 
and to 3 to 1 on the interior slopes. The necessary height of the em- 
bankment above the high-water mark depends to some extent upon the 
length and size of the reservoir, and the " reach " of the waves generated 
by winds, as well as upon the width of the spillway and the height to which 
water must rise in the reservoir during maximum floods to find full dis- 
charge through the spillway. Ample spillway capacity is of primary im- 
portance to the security of any earthen dam, unless it be one whose reser- 
voir is filled by a canal or other controllable conduit from an adjacent 
stream. A lack of sufficient spillway is the cause of the greater number 
of the failures of earthen dams that have occurred, of which the most 
memorable case was that of the Johnstown dam, whose rupture caused the 
loss of two thousand lives and the destruction of many millions of dollars' 
worth of property. Had the spillway been ot ample dimensions, this dam 
would have resisted any pressure that could have been brought to bear 
upon it and the disaster would, in all probability, never have occurred. 

A common source of failure is in the doubtful practice of buildins: the 
outlet-pipes through the body of the dam. These should either be laid in 
a tunnel at one side, or in a deep trench cut into the bed-rock or the 
solid impervious base of the dam, and the pipes surrounded by concrete, 
filling the entire trench. 

In building earth dams of any type it is essential that the earth should 
be moist in order to pack solidly, an3 if not naturally moist it must be 
sprinkled slightly until it acquires the proper consistency. An excess of 
moisture is detrimental. It should be placed in thin layers, and thor- 
oughly rolled or tamped, and the surface of each layer should he rough- 
ened by harrowing or plowing before the next layer is applied. Droves of 
cattle, sheep, or goats are often used with success as tamping-machines for 
earth embankments. They are led or driven across the fresh made ground, 
and the innumerable blows of their sharp hoofs pack the soil very thor- 

The Cuyamaca Dam. — One of the first earthen dams built in California 
for irrigation storage was the Cuyamaca reservoir-dam, erected in 1886 
by the San Diego Flume Company. It is located in a summit valley 
between two of the Cuyamaca peaks, some 50 miles east of San Diego, at 
an elevation of 4800 feet. The dam is 635 feet long on top, 41.5 feet higli^ 


with inner slope of 2 : 1, and outer slope of 1.5 : 1. The crest of the dam 
is 6.5 feet above the floor of the epillways, one of which is 90 feet and 
the other 41 feet in width. 

Before work was begun on the dam the site was covered with loose 
rock, and it was supposed that bed-rock was near the surface. Hence the 
original plan was to build a masonry dam. Excavations were started for 
that purpose, and considerable cement was brought to the ground to 
construct the foundations of masonry. It was soon found, however, that 
the loose rock was merely a surface layer on top of a bed of clay, and 
the plan was changed to a dam of earth throughout. 

The discharge-sluice of the dam was built through the center of 
the structure, and consisted of a masonry culvert 3J feet wide, 4J feet 
high, 120 feet long, resting on a bed of concrete 18 inches thick, laid 
in a trench of that depth cut in the clay. This culvert has a fall of 
3J feet in length. At its upper end is a circular brick tower, 5 feet in 
diameter inside, with an opening at the bottom 3 feet wide, 4J feet 
high, that is closed hy a ponderous wooden gate, so large and heavy as to be 
almost immovable. A second gate, 16 feet higher, of similar size and 
construction, is provided to close another opening into the tower. These 

Pig. 138.— Vtew of Cctauaca Dam and Outlet towkb. 

gates slide vertically ia wooden grooves. An iron gate inside the tower 
closes the head of the culvert. 

The bond between the earthwork and the culvert was imperfect, and 
considerable leakage ensued after the reservoir first filled, but this was 
afterwards remedied. 

Fig. 128 is a view of the dam from the side of the reservoir, showing 
the tower. 

The dam is reported to have cost $51,000 as originally constructed to 
the height of 35 feet. In 1894 an addition of C.5 feet was made to the 
height of the dam, at a cost of $3400. This addition increased the capacity 



of the reservoir to 11,410 acre-feet, covering an area of 959 acres to a mean 
depth of nearly 12 feet. The watershed tributary to the reservoir is about 
11 square miles. The following table, prepared by Mr. F. S. Hyde, C.E., 
from the records of the company in 1896, gives the volume of catchment 
and use during the first nine years after the completion of the dam: 

Table of Rainfall, Run-off, Evaporation and Average Draft from the 
CuTAMACA Reservoir, San Dieoo County, California. 

Rain and 




Run-off in 

of Run-off 

to Precipita- 



Square Mile. 




Draft from 




City Supply. 



Ft. In. 


per Day. 







8 9.50 

4 5.00 
8 9.25 
8 8.75 
8 6.75 

5 8.25 
7 1.00 
5 8.75 
5 7.50 




M<^AIlfl . . 





4 8.75 


Subsequent years of drouth have resulted in emptying the reservoir 
entirely. The rainy seasons of 1897-98, 1898-99, and 1899-1900 have 
furnished practically no water for storage. 

Referring to the above table of rainfall and run-off, it should be ex- 
plained that as the rain-gauge on which the precipitation was recorded 
is located at the dam" between two high, wooded peaks, which act as 
condensers of the moisture-laden clouds, the record shows a greater amount 
than the average of the watershed, which a few miles east of the dam 
borders on the desert, where the rainfall is known to be much less. This 
is borne out by comparing the measured run-oflE with the " Newell Curve ^' 
of run-oflE, which would indicate that if the recorded precipitation were 
a mean of the entire area, the yield should be two to three times as great 
as it actually was. This Cuyamaca rainfall record is misleading as a 
criterion of mountain precipitation in this region. The water actually 
flowing in diflEerent seasons from a known area, as shown by the table, is 
more reliable as a guide for estimates of the yield to be expected from 
adjacent sheds than any single rainfall record, or any possible collection 
of rainfall statistics without such empirical knowledge of actual yield in 
stream-flow produced by any given rainfall. 

During the period covered by the table the mean annual draft from the 


reservoir was 4331 acre-feet, while the mean atmual run-off was 5397 acre- 
feet. The difference between these figures, or 1066 acre-feet, represents 
the mean annual evaporation, or 19.75 per cent of total catchment. 

After flowing down Bowlder Creek and the San Diego River \2\ miles, 
dropping 4000 feet vertically in that distance, the water released at the 
dam is picked up and diverted to the flume by means of a masonry weir 
extending across the San Diego River. This diverting-dam is 340 feet long 
on top, 35 feet high, 22 feet thick at base, 5 feet at the crest. To cut off 
leakage under the dam a subwall was built on the up-stream side in the 
main channel, lapping onto the base of the dam and extending down 15 
feet deeper. This wall is .5 feet thick at bottom. The original wall had 
been founded on disintegrated granite. The subwall was built in a trench 
that cut deeper into the soft granite, but was not entirely effectual in 
stopping the leakage. (Pigs. 139 and 130.) 

Tia. 180.— Plab abd Elevation o¥ DrvmiTiNO-DAii or 8ah Diboo Flumk Co., 

The main flume is 34.85 miles in length, G feet wide in the clear, with 
single sideboards IG inches high, though the frame-posts arc 4 feet high 
and will admit of additional sideboards to give a total depth of 4 feet. It 
completed as originally designed, the flume would have a capacity of 5000 
miner's inches under 4-inch pressure. Its present maximum capacity is 
not over 900 inches. The flume is supported at places on high trestles, 
one of which is shown in Fig. 131, and there are a number of long and 
costly tunnels on the route. The grade of the flume is 4.75 feet per mile. 
It commands all the irrigable lands of EI Caj'on Valley, Spring Valley, and 
the San Diego mesa, and supplies wafer to about iJ^flO acres, mostly culti- 
vated in orchards of citrus fruits. The city of San Diego has also received 


its domestic supply from this source during the greater portion of the time 
since its completion, through a 15-inch steel-pipe line laid over the mesa, 
from the end of the flume to the city, about 10 miles. 

In the summer of 1897-98 the reservoir was quickly exhausted, and it 
became necessary to install an independent system of supply for the 
orchards and the city of San Diego. For the orchard supply this was 
accomplished by sinking a series of bored wells in the gravel bed of the 
San Diego River, above El Cajon Valley, where the flume leaves the 
immediate valley of the river. Pumping-stations were erected, and the 
wells, which were placed at intervals of 50 feet along a horizontal suction- 
pipe 1000 to 1300 feet in length, were drawn upon in series simultaneously, 
the water being forced up to the flume with a lift of 300 feet. About 3 
second-feet (150 inches) were thus obtained, and though the supply was 
meager it was sufficient to maintain the life of the trees and keep them 
in bearing with good cultivation. The city was supplied in a similar 
manner by wells sunk in the river-bed in Mission Valley, from 2 to 4 miles 
above the main pumping-plant. The water was lifted to the surface at sev- 
eral points and conveyed to the pump-station by small flumes. Over 
3,000,000 gallons daily were thus obtained. These plants have had to be 
maintained and increased in capacity up to the present writing (April, 
1900), with a prospect of continuance until the next rainy season. The in- 
habitants of southern California have reason to congratulate themselves 
that Nature has provided underground storage-reservoirs capable of being 
drawn upon so liberally that they are able to endure such an unprecedented 
period of drouth as they are now experiencing. To obtain the supply, 
however, by wells and pumps is generally far more costly than water stored 
in surface reservoirs. 

The Merced Beseryoir Dam, California. — The highest and longest 
earthen dam closing a reservoir chiefly devoted to irrigation in California 
is that which forms the so-called " Yoseraite Eeservoir," 6 miles north- 
east of the town of Merced. This dam was constructed in 1883-84 by the 
Crocker-Hoffman Land Company as a part of its general system of irriga- 
tion, by which some 150,000 acres are commanded for irrigation. It has 
a maximum height of 50 feet, and is built entirely of earth composed of a 
sandy clay with inner slopes of 3 : 1 and outer slopes of 2 : 1. From the 
top down for 15 feet the interior is paved with loose rock, 12 inches thick, 
for wave-protection. The entire length of the dam is 2200 feet, of which 
1400 feet is less than 10 feet high. It was built up as a homogeneous bank 
of earth, without a puddle-wall, or without adding to the natural moisture 
of the soil. The earth was simply put in place with scraper-teams, the 
material being deposited with care in thin layers. The top width is 20 feet, 
base 290 feet. The dam rests on a very firm foundation of cemented 
gravel, into which a wide, deep puddle-trench was cut and carefully re- 


Fio. 181a.— Map bhowinq Location o7 Mebcbd Rebervoir, Califobitia* 


filled. Much of the material used in the dam had to be loo&ened by 

The reservoir-outlet consists of a masonry conduit, made of brick laid 
in cement mortar, placed in a trench cut in the cemented gravel. This 
conduit carries the main, cast-iron, delivery-pipe, 24 inches in diameter, 
and a blow-off sluice-pipe. The conduit is 4 feet in diameter in the clear, 
the brickwork being 12 inches in thickness. 

The reservoir, dam, and outlet-tower are shown in Fig. 132. 

The reservoir covers 600 acres and has a capacity when full of 15,000 
acre-feet, of which about 20% is annually lost by evaporation. It is fed 
by a canal 27 miles in length, leading from a diversion- weir placed in the 
Merced River a short distance above the town of Snelling. For the first 8 
miles the canal has a maximum capacity of 1500 second-feet, which is the 
largest canal in California. The total cost of the canal system, with its 
laterals, and the reservoir was about $1,500,000. 

The watershed area of the Merced River above the head of the canal ic^ 
1076 square miles, in which is included the famous Yosemite Valley. The 
mean annual fiow of this stream as determined by the California State 
Engineering Department for the six years from 1878 to 1884 was about 
1600 second-feet, the maximum being 6510 second-feet in the month of 
June, and the minimum 65 second-feet in the months of November and 
December. During the three months of May, June, and July, when the 
greatest amount of irrigation is required, the mean discharge of the river 
in the period named was about 4000 second-feet. 

Bnena Vista Lake fieseryoir, California. — The large storage-tank 
formed of Buena Vista Lake, in the southern end of the San Joaquin 
Valley, is the largest irrigation-reservoir in the State, covering an area of 
25,000 acres to a mean depth of nearly 7 feet. The volume of water which 
it is capable of impounding above the level of the outlet-canal is 170,000 
acre-feet, and in its general characteristics it more nearly resembles the 
great tanks of India than any reservoir in this country. 

The reservoir is formed by a straight dike, or dam, 5.5 miles in length, 
following a township line from the foot-hills at the base of the mountains, 
due north. The maximum height of the dam is 15 feet, tapering out to 
nothing at either end. Its top width is 12 feet, and the slopes are 4:1 
inside, 3 : 1 outside, the crest being 4 feet higher than the high-water level 
of the reservoir when full. The erosion of this bank due to wave-action 
rendered it necessary to riprap the face with stone over a long section 
from the south end northward, where there were no tules growing to serve 
as a breakwater to lessen the effect of wave-action, as was the case at the 
north end. To procure the material for this riprap a narrow-gauge rail- 
road was built for some ten miles from a quarry at the base of the moun- 
tains. The cost of this work was more expensive than the construction 


of the embankment and brought the entire cost of the dam and outlets up 
to about $150,000. The dam divides the reservoir from what was formerly 
known as Kern Lake, before its bed was drained and cultivated. 

The reservoir now receives all the surplus water of Kern River and the 
waste at the tail end of all of the Kern Island canals below Bakersficld. 
The water thus stored is only available for use on a belt of arable land 
that was formerly a swamp, extending from Buena Vista Lake to Tulare 
Lake. This land before reclamation was periodically overflowed when 
the water of the river was not so extensively absorbed in irrigation in 
the delta and upon the adjacent plains as it has been in recent years. 
Since its reclamation it requires to be irrigated, and the reservoired water 
is devoted to that purpose. 

The reservoir was first filled in 1890, and has been in service ever since. 
Its creation was the result of the compromise of the most extensive and 
costly litigation over water-rights that has ever arisen in California. The 
title of the action was that of Lux vs. Haggin. It will go down in history 
as the case in which the Supreme Court of California, by a majority of 
one, first established the English common-law doctrine of riparian rights 
as applicable to the streams of the State. It is believed that this doctrine^ 
though greatly modified by subsequent decisions, has been a serious draw- 
back to irrigation development in California. 

The surface of the reservoir is so large as compared with the volume 
stored that the annual loss by evaporation is estimated at 120,000 acre-feet,. 
or 70% of the total capacity. This is an enormous waste of water, which 
might be saved to a considerable extent by the construction of storage- 
reservoirs in the mountains, where the ratio between surface area and 
volume would be very much less, and the rate of evaporation smaller. The 
reservoir is generally filled from about May 1st to July 20th, during the 
melting of the snows, after which time to September 1st the inflow is 
about suflRcient, ordinarily, to offset evaporation. Thus during the five 
hottest months, when nearly 70% of the total evaporation of the year takes 
place, the loss is supplied by the river, and by the return waters of irriga- 
tion. Therefore, in those seasons when the run-off is sufficient to supply 
the demand of the canals and yield a surplus great enough to fill the 
reservoir by September 1st, in addition to evaporation, the net amount 
available for use from the reservoir would approximate 125,000 to 135,000 
acre-feet. Measurements of the river taken daily from 1879 to 1884, and 
from 1894 to 1897,— ten years in all,— show a minimum yearly discharge 
of 364,000 acre-feet, a maximum of 1,760,000 acre-feet, and a mean of 
789,000 acre-feet of water discharging into the valley at the mouth of the 


The Pilaroitos and San Andr^ Dams, California. — ^The water-supply 
of San Francisco is largely derived from the storage of storm-waters on 


the peninsula south of the city. The San Mateo dam, of concrete, described 
in a previous chapter, supplanted one of the original earthen dams, that 
known as the Upper Crystal Springs; but there are two other notable 
structures still in service, called the Pilarcitos and the San Andr6s dams. 

The Pilarcitos dam is 640 feet long on top, 95 feet in height above the 
original surface of the ground, and has a top width of 24 feet. The slopes 
are 2 : 1 each side. A puddle-wall, 24 feet thick, extends down 40 feet 
below the surface, into a trench cut in bed-rock. The reservoir formed by 
the dam has a capacity of 1,180,000,000 gallons (3622 acre-feet), and 
gathers the run-off from a watershed of 2510 acres. The elevation of the 
lake is 696 feet above sea-level. 

The San Andr6s dam has a top length of 850 feet, a maximum height 
pf 93 feet above the original surface, and a top width of 24 feet. The 
inside slope is 3.5:1, while the outer slope is 3:1. The central puddle- 
wall reaches to bed-rock through 46 feet of earth and gravel. The dam 
was originally built to a height of 77 feet, but in 1875 it was raised 16 feet 
by the addition of the new material upon the outer slope. The base of the 
new section was 135 feet As the inner slope was projected to the new 
crest of the dam it became necessary to make a horizontal offset in the 
puddle-wall in order to keep it within the center of the new section. 

The San Andres reservoir has a capacity of 6,500,000,000 gallons 
(19,950 acre-feet), and intercepts the drainage from 2695 acres of water- 
shed immediately tributary. It is also fed by a flume, 17.42 miles in length, 
leading from Lock's Creek. This flume gathers the water from 1800 
acres of the Lock's Creek shed, all above 505 feet elevation. Other feeders 
to the reservoir gather the water from Pilarcitos Creek below the Pilarcitos 
dam, and from a branch of San Mateo Creek. 

Cache la Poudre Beservoir Dam, Colorado. — The Union Colony of 
Greeley, in northern Colorado, is supplied with water for irrigation by the 
Cache la Poudre Canal, an important adjunct of which is a storage-reser- 
voir of 5654 acre-feet capacity, formed by an earthen dam, 38 feet in 
height. For a long time after the construction of the canal it was thought 
unnecessary to supplement its river-supply by a reservoir. Later experi- 
ence showed that the low-water period came on in many years before the 
potato-crop was made, and a reservoir-site was sought to store water to 
carry the farmers over this critical period. The site selected was one 
which could be filled by a supply-canal, 8 miles long, discharging into the 
main canal 2 miles below its head. 

The dam was made by scraper-teams, of the soil at the site, and is 
homogeneous in character, without puddle. It was originally made with 
a uniform inner slope of more than 3 to 1, but the action of waves has 
made it quite irregular. The embankment settled 4 to 5 feet the first year 
after the water was turned in, and becomes quite soft throughout whenever 


the reservoir is filled, but this is yearly becoming less. The rock for rip- 
rapping the face of the dam was brought by rail to the nearest point, and 
hauled by wagon two miles, costing $1.10 per ton laid down. The dam cost 
$81,623 for construction, in addition to $28,643 paid for real estate and 
rights of way — a total of $110,266. The year after it was completed and 
filled, the reservoir proved its value by saving the crop of potatoes valued 
at $331,366, of which one-half is credited to the reservoir. 

The feeder-canal has a capacity of 150 second-feet, while the outlet- 
canal will carry 200 second-feet. 

The outlet-conduit is founded on tough clay, and has a floor of wide 
flagstones laid on concrete. The conduit is 5 feet wide, and 5 feet high 
in center, the side walls being 2^ feet high, and a semicircular arch form- 
ing the roof. Two collar-walls extend into the embankment to cut off 
leakage. The gates are the invention of Gordon Land, a well-known 
hydraulic engineer of Denver, and are known as " railroad gates." They 
are two in number and travel on a double track, set at an inclination of 
20** from the vertical, the gates being provided with wheels. They go 
down to their seats by gravity, and are raised by wire ropes passing over 
a windlass at the top of the embankment. 

Colorado State Dams. — In 1892 the State of Colorado by legislative 
enactment inaugurated a system of storage-reservoirs for irrigation, under 
which five dams were erected in different parts of the State by money 
appropriated for the purpose by the State legislature. This is a policy 
which has not been attempted by any other of the States of the Union, 
so far as the writer is aware, and in this case it does not appear to have 
been successful or to meet with popular favor. The dams are under the 
control of the State Engineer, and water from them is sold to the irriga- 

The selection of the sites and the expenditure of the money appear to 
have been controlled by politics rather than by good engineering. The 
experiment cost the State $102,544.88 in all, and the total storage provided 
was but 2574 acre-feet in the aggregate. An account of these works, 
gleaned from the State Engineer's reports, is of interest, and is con- 
densed as follows: 

The Monument Creek Dam. — This earthen dam is located on Monument 
Creek, some 15 miles north of Colorado Springs, at an elevation of 7000 
feet above sea-level.* Its dimensions are the following: 

Maximum height 40 feet 

Width on top 20 ^' 

Length on top 855 *' 

Inner slope 3:1 

Outer slope 2:1 


The water-line is 7 feet below the crest of the dam. The inner face of 
the dam is covered with a clay puddle-wall laid on the slope, with a hori- 
zontal thickness of 50 feet at the base and 10 feet at top. This puddle is 
carried down to bed-rock in a trench 14 feet deep, at the inner toe of the 
dam, the minimum width of the trench being 5 feet. Over the puddle-wall 
is laid a riprap wall of stone, placed with care by hand. The outer half 
of the dam is composed of coarse gravel, rock, and earth. These general 
principles must be regarded as unexceptionable in earth-dam construc- 

The reservoir-outlet is formed by two 16-inch cast-iron pipes, laid in a 
trench excavated underneath the dam, with concrete collars, 12 inches 
wide and the same thickness, at each of the joints. Between these collars 
the trench was filled with puddled clay. Just above the inner line of the 
crest of the dam a gate-tower is carried up through the embankment from 
the level of the outlet-pipes. At the bottom of this tower two 16-inch 
stop-valves are placed in the outlet-pipes, their stems reaching to the top 
of the dam inside the tower. The tower is circular in form, 4rJ *feet inside 
diameter for the lower 8 feet, and 3 feet diameter for the remaining 
height. It is built of sandstone, 18 inches thick, laid in cement. The 
entire tower is encased in puddled clay. 

The spillways provided each side the dam have a total width of 200 
feet, although 50 feet width was regarded as probably ample to carry the 
maximum floods from the 22 square miles of drainage-area. 

The dam was planned and built under the supervision of J. P. Maxwell, 
State Engineer. The work was done by contract for $25,000, exclusive 
of engineering, but when finally completed in 1894 its entire cost had 
reached $33,121.53. The award of the contract was made subject to the 
proviso that El Paso County, in which it is located, should furnish, without 
cost to the State, a clear title to the land required, which was done. 

It was estimated that the reservoir could be filled three or four times 
every year, but it is found to fill once and sometimes twice in a year. 

The reservoir covers 62 acres to a mean depth of 13.8 feet, or 42% of 
the maximum depth. It impounds 885 acre-feet. 

Tlie Apishapa State Dam is located in the Metote Canyon in Las Animas 
County, and was completed in 1892. The dam is of earth, and forms a 
reservoir of 459 acre-feet capacity. Its cost was $14,771.80. It is filled by 
a ditch, 2 miles long, leading from Trujillo Creek, which has 30 square 
miles of watershed, the water from which is fully appropriated and used 
by prior locators. 

The Hardscrabble State Dam is an earthen structure, completed by the 
State in 1894, at a cost of $9997.31. It impounds but 102 acre-feet of 
water, and is filled by a ditch from Hardscrabble Creek, in Custer County. 

The Boss Lake State Dam is located in Chafifee County, on the head- 

298 RBaEBVonta for irrigation, water-power, etc. 

waters of the South Arkansas Eiver. It was finished in 1894, at a cost 
of $14,654.24, and forms a reservoir with a capacity of 205 acre-feet. It 
is made of earth, and was reported to be unsafe in construction and was 
never filled. The tributary watershed is 4 square miles. 

The Saguache State Dam is located near the town of Saguache, and is 
an earthen dam which cost $30,000. The reservoir capacity behind it is 
954 acre-feet. It is filled by a ditch from the Saguache Eiver, but as the 
normal fiow of the stream is fully appropriated, only the winter and spring 
floods are available. 




On the great plains east of the Kooky Mountains there are thousands 
of natural basins which have no outlets and which gather the storm-water 
run-off from a few hundred acres of surrounding territory, and hold it in 
shallow ponds until it is lost by evaporation. Many of these depressions 
hav^ been utilized as storage-reservoirs by carrying water to them from 
adjacent streams, and by providing them with outlets, either by tunnels 
or cuts; and many more have been selected for future utilization. They 
Are often at the proper elevation to command large areas of arable land, 
And can usually be converted into safe storage-reservoirs at small expense. 
Such natural basins appear to be invariably water-tight, and in every way 
suitable to the purpose, except in occasional instances where they contain 
■deep beds of alkali. 

The Alpine Reservoir, California. — The project of the South Antelope 
Valley Irrigation Company, completed in May, 1896, and put in service the 
following year, is dependent upon a reservoir, formed in a natural basin, 
which has unusual features and is of special interest, not only as the 
first reservoir of any magnitude completed on the borders of the Mojave 
Desert in southern California, but because it lies directlv in the line of 
what is known as " the great earthquake crack '* of this region, which is 
marked by a series of similar basins behind a distinct ridge that appears 
to have been the result of the great seismic disturbance. 

This remarkable line of fracture can be traced for nearly 200 miles 
through San Bernardino, Los Angeles, Kern, and San Luis Obispo coun- 
ties, and deviates but slightly here and there from a direct course of about 
N. 60** W. There appears to have been a distinct " fault " along the line, 
the portion lying south of the line having sunken, and that to the north 
of it being raised in a well-defined ridge. In many places along the great 
crack ponds and springs make their appearance, and water can be had in 
wells at little depth anywhere on the south side of the ridge before 
mentioned. A tough, plastic, blue clay distinguishes the line of the break 
in this portion of its course, at least, and where the line crosses Little 



Rock Creek the blue clay has formed a submerged dam^ which has forced 
the underflow to rise near the surface and created a ^^ cienega ^^ immediately 
above it. After crossing the line the water of the creek drops quickly away 
into the deep gravel and sand of the wash. The same effect is noticeable 
at other streams^ and the earthquake crack has been suggested as the 
probable cause of the very distinct rim marking the lower margin of the 
San Bernardino Valley artesian basin and confining its waters within well- 
defined limits^ as this rim is nearly on a prolongation of the line that is 
traceable on the north side of the mountains, — the break having possibly 
crossed the mountains through the Cajon Pass on the line of Swartout 

One of the largest depressions on the earthquake line is the basin near 
Alpine or Harold station on the Southern Pacific Sailroad, which has 
always held a small amount of water, supplied by the rainfall over the 
small catchment of 6 or 8 square miles above it, but which is now trans- 
formed into a reservoir fed by a canal, 8.6 miles long, from Little Bock 
Creek. The railway passes through one side of the basin and crosses the 
outer rim near the outlet-tunnel. A low levee or dike, about 4000 feet 
long, will have to be built alongside the track to enable the reservoir to 
be filled to its maximum depth of 34 feet, for which it has been planned. 
At this level it will cover 263 acres of surface and impound 5500 acre-feet 
of water. The basin will carry 15 feet of water without submerging the 
track, and for present purposes a dike lower than that which is planned 
for a full use of the basin has been built to permit the storage of 21 feet ' 
depth of water. A corner of the basin is shown in Fig. 135 as it appeared 
before beginning work. The view is taken looking east across the railroad- 
tracks toward the mountain source of supply. 

The feeder-canal from Little Rock Creek consists of 2 miles of flume 
and chute and 6^ miles of earth canal, including two ponds used as sand- 
settling basins, 1600 and 1400 feet long. The location of the conduit, 
after getting out of the canyon of the creek, is directly on the earthquake 
line for the greater part of the way, the straightness of the line being 
noticeable on the map. Fig. 134. The canal heads at an elevation of 
3130 feet above sea-level, and it has a total fall to the surface of the reser- 
voir of 317 feet, of which the canal grade required but 70 feet. The 
superfluous fall was taken up by a series of inclines or chutes, down 
which the water flows with great velocity. They are seven in number and 
have a total length of 4600 feet. 

The canal has a maximum capacity of 250 to 300 second-feet. Under 
normal conditions it is expected that the reservoir can be filled twice or 
more each season, and by irrigating freely in winter and early spring the 
duty of the reservoir and canal system may be increased to accomplish the 
irrigation of as great an area as though the reservoir were of double the 



capacity. The tract which the company hopes to supply from this source 
covers about 10,000 acres, a part of which is being planted in olives. 

The watershed of Little Eock Creek, as shown by the best maps to be 
had, does not exceed 61 square miles, but as it heads in one of the highest 
peaks of the Sierra Madre and drains the north slopes of the mountain, 
the run-off to be expected from it may ordinarily reach 400 acre-feet per 

Fig. 184.— Map of Little Rock Creek Ibbigation District. 

square mile. The normal flow of the stream, which reaches a minimum of 
2 second-feet, is diverted at the before-mentioned earthquake cienega by 
a ditch supplying the Little Rock Irrigation District, the outlines of which 
are shown on the sketch-map {Fig. 134). Consequently the South Ante- 
lope Valley Company must depend entirely upon the surplus flood-water 
after the district is supplied. 

Incidentally it will be of interest in this connection to mention that 
a careful measurement of the underflow in the gravel bed of the stream 
overlying the blue clay of the earthquake crack, made by Mr. J. B. 
Lippincott in June, 189(), resulted in the conclusion that the rate of flow 
of the percolating water passing through the sand and gravel of the 


channel was 2.16 feet per hour, or 3.53 miles per annum, which is ex- 
tremely slow, but much greater than that noted at the Agua Fria River, 
Arizona (p. 210), doubtless because of the greater coarseness of the gravel 
at Little Rock. 

The outlet to the Alpine reservoir (Figs. 135, 136) is made by a tunnel 
750 feet long, in which a 36-inch riveted steel pipe is laid for irrigation 
supply alone, and a 10-inch pipe of the same character is placed above 
the former for domestic purposes only, both being surrounded with con- 
crete, filling the 8-inch space concentric with the pipes to the walls of the 
tunnel. The pipes extend only 200 feet from the interior to a. gate-shaft, 
and thence the main pipe discharges into a flume placed inside the tunnel- 
timbers^ This flume is 2 feet deep, 3 feet 8 inches wide, and delivers the 
water to the distributing-ditches running east and west from the mouth 
of the tunnel on suitable grade-lines. A wooden platform on a trestle 
built over the inner end of the tunnel serves as a place from which to 
operate the 36-inch gate- valve at the head of the pipe and three 10-inch 
valves on a stand-pipe at different levels controlling the domestic supply, 
which is taken under pressure to the town of West Palmdale. The works 
were planned and built by Burt Cole, a civil engineer residing in the dis- 
trict. The cost of the system was about $100,000. 

Twin Lakes Reservoir, Colorado. — One of the reservoir-sites surveyed 
by the government in 1892 was the Twin Lakes site, on a fork of the 
Arkansas River (Fig. 137). These lakes cover an area, at normal stage of 
water, of about 1900 acres, and have a depth of more than 80 feet. They 
are at an altitude of 9194 feet, and receive the drainage from 387 square 
miles of watershed, including within this area some of the highest moun- 
tains of Colorado. The annual run-off from this area is from 40,000 to 
100,000 acre-feet. 

The plan proposed by the government engineers for utilizing these two 
lakes and converting them into one large reservoir was to erect an earth 
dam, with a maximum height of 73 feet, across the valley below the lakes, 
and thus increase their surface area to 3475 acres. This would give a 
reservoir capacity above the normal lake surface of 103,500 acre-feet. 
To fill the reservoir it was designed to supplement the run-off of the 
streams directly tributary by diverting water from the main Arkansas 
River, by a canal leaving the river a short distance below Leadville. 

Some years after this survey was made a private corporation, called the 
Twin Lakes Reservoir Company, was organized by Buffalo capitalists to 
carry out the work on a modified plan. This company acquired sufficient 
land around the margins of the lakes to control them, and began work 
in the summer of 1898. The plan adopted by them contemplated work^ 
that would enable them to draw off the lakes to 16 feet below their normal 
level, and in addition build a low dam that would store 9 feet in depth 


above that level, — thus commanding a total depth of 25 feet and a total 
volume of 48,000 aere-feet. Of this volume, two-thirds, or 32,000 acre- 
feet, is below the normal lake-level. In pursuance of this plan they ex- 
cavated a canal at one side of the outlet-stream, 2000 feet long, from 
the edge of the lower lake to the point of its intersection with Lake Creek. 
This canal is 40 feet wide on bottom, and has a maximum depth of 37 feet. 
The excavation was in sand, bowlders, and silt, or " glacial flour," and was 
chiefly made with a ateam-shovel. At the point where the excavation wm 

L^ ^*"^^ 



Canal Section 



"H ■■•.. 

-i^ — , 


7 1 1 ? 3 2 T 3 3 ;5 3 '''ZSn*', 

Icnyffai/inal Ste.^ Outl^ Tanne/ from naamr^Oir Sa^^^ «^T 1 -Sma 

•/7g *^ecBencf> f/ume 

Fia. 186.— Details of Tunnel- ootlrt of the Alfink l<Ei:ii:itv<jiii. 

deepest, some 300 feet from the lake margin, they prei)ared to erect head- 
gates of iron, on a heavy base of concrete, with abutment- walls of cut 
stone laid in cement mortar. The structure was to have been 32 feet in 
height. The gates were twelve in number, each 2 feet 8^ inches wide, 
.5 feet high, made of ^-inch boilor-plate, and carrj^ing iron flashboards, 
loosely resting one above another, on top of the gate, and reaching up to 
above high-water mark. The gates were to slide vertically between 12-inch 
I beams. These beams were to he embedded in the concrete floor. The 
foundations for this floor were made by driving piles, upon which the 
abntment-walls and center pier rest. (Fig. 138.) 

The concrete base of the gate structure was planned and built 72 fget 
long, with a width of (iff feet to the' outer lines of the a hutment- walls. It 
,was made .5 feet in thickness, with double grillage of T rails, encased in 
the concrete. Three lines of apron or curtain walls extended down 5 feet 
below the bottom of the concrete, across the line of the canal. 

Fig.' 137. 

[To face page 807. 



ner H.BodfifiK,Eingineer. 

1 Capacity 103500 Acre Feiet^ 







In the spring of 1899 this structure was partially completed, the floor 
was finished, and one of the abutment-walls was built 12 feet high, when 
work was stopped by threats of injunction made by officials of the Denver 
and Bio Grande and the Colorado Midland railways, whose tracks through 
the canyon of the river below would have been endangered by any failure 
of the proposed reservoir. At this juncture Mr. 0. 0. McEeynolds was 
appointed Chief Engineer, and the writer was employed as Consulting 
Engineer to prepare plans to make the work secure and allay apprehen- 
sions of its safety. The modifications which were made in the plan are 
shown in Fig. 137, and the work has since been completed in compliance 
with the new design. The changes were made in such manner as to adapt 
them to the part already completed and to utilize materials already on the 
ground. These were the following: A series of four culverts were built 
on top of the completed floor, extending from the line of gates to the 
lower edge of the concrete platform, a distance of 47 feet. These culverts 
are each 7 feet 11 inches wide and 7 feet high, with a semicircular arch 
over them. They are built of concrete, the thickness of the arch being 
2 feet. On top of these culverts a masonry dam is built across the canal, 
reaching to a height of 30 feet above the floor of the structure. This 
wall is of sandstone ashlar, laid in large blocks with Portland-cement 
mortar. Its base width is 15 feet, top 4 feet; down-stream batter 5 : 12. 
Extending welf into the banks on each side, in line with the dam, is a con- 
crete wall, 2 feet thick, designed to cut off seepage through the earth 
filling on the sides that would tend to pass around the dam. Against the 
masonry dam on the lower side is an embankment of earth over the top of 
the culverts, forming a driveway over the canal, 22 feet wide on top. 
The outer slope terminates against a low wall forming a fagade for the 
culvert-portals. The slope is paved with stone. For 50 feet above 
and 75 feet below the concrete platform the canal is paved with con- 
crete on the bottom, and the sides protected from erosion by substantial 
walls of concrete above the dry rubble below the headworks. The gates 
built for the original design were used, but the hoisting-device was im- 
proved, and a substantial gate-house built over the gates. 

Spillway. — A space is left between the gates and the masonry which 
will admit of a maximum discharge of 600 second-feet over the top of the 
flashboards, without raising the gates. Whenever any water thus passes 
over the top of the flashboards it can escape freely through the culverts 
and down the canal. This provision for sudden floods in the possible 
absence of attendants to open the gates is considered an ample spillway 
allowance. The culverts have a combined capacity of over 2000 second- 

Fishway, — To provide for a free passage of migratory fish over the 
dam, in compliance with the State law, it is proposed to erect a fish-ladder 


Fia. 138. — Details or OnrLETs for Twik Lakes, Colo. OEsiaMBD for the 
Twin Lakes Rebertoik Co. bt J. D. Schcileb, Cohb. Esait., and built bt 
O. O. HcRbtnolds, Chief Emsinbeb. 

.'» • 


of approved design, supplying it with water piped from a neighboring 
stream. The lakes abound in trout. 

The entire cost of the improvements, including the purchase of valuable 
villa sites on the lake margins, will be about $200,000. The works were 
finished during the current year (1900). 

" Olacial Flour." — ^An interesting feature of these improvements is the 
peculiar character of the material through which the canal has been 
excavated and upon which the head-works have been built. The lakes are 
located between two great lateral moraines, hundreds of feet in height, 
while the barrier across the valley, forming the natural dam inclosing 
the lower lake, is a terminal moraine deposit, consisting largely of rock 
dust, or almost pure silica ground to an impalpable powder, known to 
geologists as ^^ glacial flour.'' This material is so fine in texture as to 
resist percolation through any considerable mass of it, and hence it be- 
comes practically impervious as an embankment of ordinary dimensions. 
It is neither quicksand nor clay, and has none of the characteristics of 
these elements. 

The natural channel through which the lakes overflow into the 
Arkansas Biver will be closed by an embankment of this glacial flour^ 
well riprapped with stone on both sides. 

Larimer and Weld Reservoir. — One of the natural basins, located 1^ 
miles north of Fort Collins, Colorado, has been made to hold an important 
auxiliary supply to the Larimer and Weld canal, feeding into the latter 
2 miles below the head of the canal. When filled to the rim it holds a 
maximum depth of 25 feet, and has a storage capacity of 7700 acre-feet 
at that level. This capacity was increased in 1895 to 11,550 acre-feet by 
constructing a low levee or bank about 2000 feet long at the lowest part 
of the rim of the basin. This added 5 feet to the depth of water in the 

The cost of the improvements was $21,796, but land and water rights, 
attorneys and court fees, and miscellaneous expenses swelled the entire 
cost to $64,782. On the same canal system are two other natural basins, 
utilized as reservoirs, the larger of which, called the Windsor reservoir, is 
25 miles below the head of the canal. It carries a maximum depth of 28 
feet of water, and cost $52,000, of which $25,000 was for the land and 
attorneys' fees. To increase the depth to 40 feet, an embankment is to be 
built which is estimated to cost $23,000 additional. The reservoir will 
then have a capacity of 23,000 acre-feet. 

The Larrimer County Canal utilizes six of these basins on the plains, 
as storage-reservoirs, which have a combined capacity of 10,860 acre- 

All of these basins above described derive their water-supply from the 
Cache la Poudre Eiver. 


Harston Lake. — One of the largest of these natural basins^ situated at 
an elevation to command the city of Denver, has been utilized by the 
Denver Union Water Company as a storage-reservoir of 5,000,000,000 
gallons capacity. It is fed by a canal from Bear Creek, and is provided 
with two outlet-tunnels which connect with the main conduits leading to 
the city of Denver, 10 miles distant. 

Loveland Beservoir-site. — One of the largest of the natural-basin 
reservoirs that has been projected for use in Colorado is located 3 miles 
northeast of Loveland, Colorado, at Boyd Lakes. These are two basins 
adjacent, each containing small lakes, on the high ground between the 
Cache la Poudre and Big Thompson rivers. The basin will require no 
dam, and when filled will have a maximum depth of 44 feet, and a surface 
area of 1920 acres, the capacity of which will be 45,740 acre-feet. 

The method proposed for its conversion into a reservoir is to make an 
open cut, 10 feet wide at the bottom, on a grade of 1.5 feet per mile. At 
the deepest point in the cut a masonry wall is proposed to be built across 
the cut, with six 3-foot, cast-iron pipes passing through the wall. The 
reservoir would be fed by two canals from the rivers on each side of it. 
The entire cost of the improvement is estimated by Capt. H. M. Chitten- 
den  at $262,106.34, or $5.73 per acre-foot of storage capacity. 

The Laramie Natural Reservoir-site, Wyoming. — Capt. Chittenden's 
able report f on reservoir-sites in Wyoming and Colorado describes a 
natural basin that could be made available for storing the surplus water 
of the Laramie and Little Laramie rivers, which is one of colossal magni- 
tude. Its maximum depth is 170 feet, covering an area of 13,651 acres, 
and having a capacity of 937,038 acre-feet. This is greatly in excess of 
the supply available from the two streams mentioned, which is estimated 
at 70,000 acre-feet annually, although this could be increased by gathering 
the supply from more distant sources. 

When filled to the 100-foot level, the annual loss by evaporation would 
be 24,000 acre-feet, leaving a supply of 46,000 acre-feet for irrigation. 
The estimated cost of the canals, reservoir-outlets, rights of way, etc., 
for utilizing the basin on the basis of storing only the waters of the two 
Laramie rivers, was $416,254, or $9.05 per acre-foot of average supply. 

Lake De Smet Reservoir-Bite, Wyoming. — Among the reservoir-sites 
examined and reported upon by Capt. Chittenden, in the report quoted 
above, was a natural depression without outlet, called Lake De Smet. 
This basin is 3 miles long, 1 mile wide, and covers an area of 1965 acres. 
The improvement of this basin which he recommended was to construct 

 Report of Capt. Hiram M. Chittenden, Corps of Engineers, U. S. A., upon examina- 
tion of Reservoir-sites in Wyoming and Colorado, nnder the provisions of Act of Con- 
gress of Jnne 8. 1896. House Document No. 141, 55th Congress, 2d Session. 



a feeder-canal, 3^ miles long, with a capacity of 727 second-feet, and con- 
struct two outlets, one at each end of the basin, discharging into Box 
Elder Creek on one side and into Piney Creek on the other, each to have 
a capacity of 425 second-feet. This would convert the basin into a reser- 
voir by the addition of 30 feet in depth, bringing the level of the lake up 
to the rim of the basin, increasing its surface area to 2400 acres, and 
aflEording an available storage of 67,627 acre-feet of water. The entire cost 
of the improvement was estimated at $113,360, or $1.67 per acre-foot of 
storage capacity. 

Such natural basins as those described in the foregoing pages, which 
can be filled by controllable canals, present advantages as storage-reser- 
voirs which are certainly ideal. The great thickness of the natural ridges 
which surround them renders them absolutely safe against bursting, pro- 
vided their outlets are properly designed and well constructed; they are 
generally quite free from loss by percolation, and the volume of silt de- 
posited in them is in direct ratio to their capacity, as no more silt-laden 
water need be put into them than is drawn out of them for use, in addition 
to evaporation, whereas a reservoir located in the channel of a river may 
often have to receive the silt from a volume of water many times the 
reservoir capacity. The only disadvantage they possess is that the surface 
area exposed may be greater per unit of volume stored than in deep reser- 
voirs formed by high dams, and consequently the ratio of loss by evapora- 
tion may be somewhat greater. 

This disadvantage is, however, amply offset by the many superior 
features they possess when compared with the average stream-bed reser- 

Natural Beservoirs of the Arkansas Valley, Colo. — The most extensive 
enterprise for the storage of flood waters for irrigation in natural-basin 
rpservoirs yet undertaken in the West was recently completed by The Great 
Plains Water Company in the Arkansas Valley in Eastern Colorado, and 
the reservoirs were partially filled and used for the first time during the 
irrigation season of 1900. The reservoirs are five in number, lying in a 
group closely adjacent to each other, and have the following capacities: 

* Name of Reiervoir. 

Nee 8opnh.. 
Nee Gronda. 
Nee Noahe. . 





Vnlnme below 
Outlet I^vel 











A callable 
for Use. 





* The Dames of the reservoirs are from the Osage Indian language, nnd have the 
followincr interpretations : Nee Sopah, Black-water ; Nee Gronda, Big-water ; Nee 
Noehe. Standing-water ; Nee Skah, White- water. 


The reservoirs are located 12 to 18 miles north of the town of Lamar, 
and are fed by a canal from the Arkansas River, which heads near La Junta, 
Colo., and has a maximum capacity of 2096 second-feet. The company 
has built various other canals, as shown by the following table: 

Name of Canal. ^m8S.*" ^S?-ff. *" 

Fort Lyon 113.00 2096 

Kicking Bird 36.50 1000 

Satanta 12.50 300 

Comanche 16.78 400 • 

Pawnee 6.34 200 

Amity 110.00 870 

Bujffalo 16.10 192 

The company has invested about $2,250,000 in its irrigation works and 
lands, the area of its holdings being about 100,000 acres. The manager of 
the company is Mr. W. H. Wiley, of New York, now residing at Holly, 

The three reservoirs described in the foregoing table are so connected 
that they can be drawn upon by one outlet. This has been formed by a 
deep cut through the rim of the basin, in which the gates are placed in 
substantial headworks of cut-stone masonry. The outlet to Nee Skah is 
of a similar plan. The King reservoir as yet has no outlet provided for it. 

Natural Oravel-bed Storage-reservoirs. — It may be said that all the soil 
of the earth is a storage-reservoir, which receives a large proportion of the 
precipitation from the clouds and gives it off slowly to feed the natural 
springs by which the normal flow of the streams is maintained. These 
natural reservoirs are increased in capacity and useful function by a 
maintenance of the forests, which shade the ground, lessen the force of 
the winds, increase the humidity of the air, diminish evaporation, and knit 
the soil together with a network of roots and so enable it to resist erosion. 

In many parts of the country the storm-waters from the mountains 
flow over great beds of coarse gravel, extending from the foot-hills out into 
the valleys, for many miles. These gravel beds constitute natural storage- 
reservoirs of enormous capacity, and if, at some lower point, a contraction 
occurs in the stream-channel, or some natural barrier intercepts the flow, 
the water is again forced to appear on the surface and feeds the stream by 
a constant outpouring from the gravel reservoir, long after the feeders of 
the reservoir have gone dry. 

In southern California there are a number of such natural reservoirs, 
one of the most notable of which is in the San Fernando Valley, north of 
Los Angeles, and supplies, by its natural overflow, the Los Angeles River. 
The San Fernando Valley has an area of 182 square miles, about one- 


fourth of which is a deep hed of coarse gravel, constituting a natural 
storage-reservoir. The valley is surrounded by mountains, of which about 
300 square miles in the area drains into the valley. At its outlet the valley 
narrows down to a width of about 2 miles, and at this first contraction 
the Los Angeles River begins to appear, growing by rapid accretions in the 
space of a mile or more, at the rate of 10 to 25 miner's inches per 100 feet 
of channel. All the streams flowing into the valley are intermittent, and 
for months at a time have practically no surface-flow. The overflow of the 
gravel reservoir, however, is practically constant through all seasons, wet 
and dry, maintaining a discharge of from 70 to 90 second-feet. Even after 
three seasons of drouth the river at the present writing shows a diminution 
of but about 15% from the normal. 

The TTpper San Oabriel Valley, some 15 miles east of Los Angeles, 
constitutes another natural reservoir, of somewhat greater discharge than 
that of the Los Angeles River. The passage of the stream through the 
coast range of hills is but one mile in width, and contracts the basin 
sufficiently to cause the reservoir to overflow at the surface, producing 
a never-failing water-supply for irrigation in the valley below. Near the 
outlet of the upper valley a number of artesian wells have been bored 
which pierce strata of impervious clay and add considerably to the natural 
output of the reservoir. 

The San Bernardino Valley is another interesting example of nature's 
storage-reservoirs, whose overflow at the narrows below yields a large and 
unfailing supply to the adjacent irrigated districts. This valley also pro- 
duces a large artesian flow to augment the supply which naturally seeks 
outlet to the surface, as the overflow of the gravel reservoir. 

Only second in importance to these natural reservoirs which retain 
water and let it out to the surface at a uniform rate, where it may be 
diverted by gravity to the lands, are the great artesian basins fed by under- 
ground streams, which require to be tapped by the boring of wells, and 
the more numerous and widespread subterranean basins from which water 
in wells may be pumped in practically immeasurable quantities. 



If all the reservoirs which have been surveyed and projected in arid 
America within the past ten years were to be constructed, the water- 
supply which they would conserve for irrigation \yould doubtless far ex- 
ceed in volume all the water which has ever been made use of from the 
natural streams, or from the reservoirs already built, while there are still 
vast numbers unexplored which may be developed in the future. 

In 1890, '91, and '92 a comprehensive series of reservoir locations were 
made by the U. S. Geological Survey, and by Act of Congress the lands 
covered by the sites selected were segregated and withdrawn from public 
entry. The detail of this work is found in the 11th, 12th, and 13th 
Annual Reports of the TJ. S. Geological Survey. 

In the appendix will be found tables giving the data of these various 
reservoir-surveys, the height of dams required, the area of reservoirs and 
their storage capacity. The work was distributed over the following States 
and Territories, viz.: 

California 45 reservoir-sites. 

Nevada 2 " 

J Colorado 55 " 

Montana 48 " 

New Mexico 39 " 

Utah 13 " 

Wyoming 1 " 

Idaho 1 « 

Total 204 


The most capacious rcscrvoir-site discovered by the survey at this 
time, and doubtless the largest in the United States, was the Swan Lake 
reservoir, on Snake River, Idaho, covering an area of over 32 square miles, 
and capable of impounding 1,500,000 acre-feet, with a dam 125 feet in 
height. The cost of the dam was estimated at $500,000. This consider- 



ably surpasses the proposed Swift River reservoir in Massachusetts, whose 
capacity is given at 1,245,000 acre-feet, or 406 billions of gallons. 

Projected Beseryoirs in Wyoming. — Reference has been made in a 
previous chapter to the able report of Capt. H. M. Chittenden, U.S.A., 
to the Secretary of War, on reservoir-sites in Wyoming and Colorado. The 
examination of this matter was authorized by the River and Harbor Act 
of June 3, 1896, providing for '* the examination of sites, and report upon 
the practicability and desirability of constructing reservoirs and other 
hydraulic works necessary for the storage and utilization of water, to 
prevent floods and overflows, erosion of river-banks, and breaks of levees, 
and to reenf orce the flow of streams during drought and low-water seasons, 
at least one site each in the States of Wyoming and Colorado. 

A number of the views which appear in this book have been kindly 
loaned by the public printer, having first been used to illustrate Capt. 
Chittenden's report, for which the writer makes due acknowledgment. 

Five reservoir systems were examined under the provisions of the 
Act of June 3, 1896, — three in Wyoming, two in Colorado. The Wyoming 
reservoirs reported on were the Laramie site, the Sweetwater site, and the 
Piney Creek system, comprising three reservoir-sites, viz., the Cloud Peak, 
the Piney, and the Lake De Smet sites. The sites examined in Colorado 
were the Loveland site, already described in a previous chapter, and the 
South Platte site, 50 miles above Denver. At the latter site the Denver 
Union Water Company is constructing a high dam, which is described in 
the chapter on Rock-fill Dams. 

The Laramie and Lake De Smet sites have already been referred to in 
a previous chapter, in the class of natural basins. 

The Sweetwater Site is located on the Sweetwater River, at a point 
known as the Devil's Gate, about 65 miles north of the town of Rawlins, 
Wyo. The river here cuts through a granite ridge with a remarkably nar- 
row gorge, and only about 35 feet wide at the water-surface, 330 feet deep, 
and 400 feet wide on top. The top length of the dam at the 100-foot level 
will be but 150 feet. Here it is proposed to build a masonry dam about 100 
feet high, which would form a reservoir 13 miles long, covering an area of 
10,578 acres, and having a storage capacity of 326,965 acre-feet. The cost 
of the work is estimated at $276,484.80 or 85 cents per acre-foot of ca- 
pacity. The available supply for storage is stated at about 100,000 acre- 
feet annuallv. 


The profile of the dam proposed is of heavy dimensions, the base width 
being 94 feet and the thickness at crest 25 feet, yet with these dimensions 
the entire cubic contents of the dam are but 21,534 cubic yards. The 
proposed outlet is by a tunnel 1000 feet long in the solid rock around the 
base of the dam. The estimate includes an item of $75,000 as the value 
of the land flooded by the reservoir. 


Capt. Chittenden says of the dam-site: "It stands almost without ex- 
ception as the most favorable site for a masonry dam in the world." 

The accompanying photograph, Fig. 139, corroborates this statement. 
A gap in the ridge at one side of the dam limits the height to 100 feet, and 
aflfords a natural spillway of any desired capacity. 

The Cloud Peak Site is a natural lake, about 1^ miles long and i mile 
wide, covering 173 acres. Its elevation is nearly 10,000 feet above sea-level, 
and it is surrounded by high mountains densely clothed with forests. The 
dam proposed for this site is the combination earth and rock-fill of the 
Pecos Valley type. The rock-fill is planned with side slopes of 1:1, and 
a top width of 6 feet. Against this is to be built an embankment of 
puddled earth, with a crest width of 20 feet, and inner slope of 3 : 1. The 
total height is 34 feet, top length 820 feet. A wasteway, 100 feet wide, 
6 feet deep, is planned. The high-water mark will be 4 feet below the crest 
of the dam. By means of a sluiceway, cut 10 feet deeper than the base 
of the dam, it is proposed to draw down the lake-level 10 feet, giving a 
total available capacity of 6800 acre-feet. The drainage-area is 30 square 
miles in extent, from which the run-off will fill the. reservoir every year. 
The estimated cost of the work was $31,048, or $4.56 per acre-foot of 
storage capacity. 

The Pincy Site is located 6 miles below the Cloud Peak site, at an 
altidude of 8800 feet. It requires a dam 54 feet high to store 11,020 
acre-feet, covering a surface area of 328 acres. The dam proposed is about 
1000 feet long, and is planned to be of the same type as the Cloud Peak 
dam. Its cost is estimated at $70,226.25, or $6.37 per acre-foot. The 
total drainage-area above this site is 65 square miles. 

Capt. Chittenden has given in his report the ablest and most convincing 
arguments in favor of the construction of storage-reservoirs in the arid 
West by the U. S. Government that have yet been advanced by the most 
ardent advocates of that policy. He says: 

" Of the very great importance of irrigation, not only to the West but 
to the country at large, there would seem to be no room for doubt. To one 
who has seen the changes wrought in the once desert regions of California, 
Arizona, Utah, Wyoming, and Colorado, in what used to be as forbidding 
regions as any still remaining in that country, there can be no doubt that 
the destiny of the arid section of America is more dependent upon the 
waters that flow from its mountains than upon the minerals that lie con- 
cealed within them. Already in the greatest mineral-producing States of 
the West, California and Colorado, irrigated agriculture yields a greater 
wealth of product than the mines. . . . Already in many sections the 
natural flow has been used as far as it is practicable to do so. . . . Here, 
then, is a definite reason of the highest validity for the construction of 
reservoirs. . . . The inevitable tendency of Western development is there* 

FiQ. 189.— Tbk '■ Devil's Gate," Sweetwater Ritkr, Wtominq. 


fore to store the waters of the streams, and the limit of development in 
this direction seems certainly to be nothing less than the final utilization of 
all their flow. As reservoirs are indispensable aids to this end, it will be 
seen that their construction as an element of growth of the Western coun- 
try is not merely ^desirable' — it is absolutely necessary. What is the 
proper agency to do the work? " 

After discussing the financial, legal, commercial, and physical difficul- 
ties in the way of these works being carried out by private individuals or 
corporations on any adequate scale, he says: 

"The matter of private or corporate construction of these storage- 
works is therefore seen to be one of very doubtful practicability from a 
financial point of view alone, while in neither case is it likely that reser- 
voir-sites would be developed to their full capacity, as they should be, but 
only to the extent that would be most advantageous to the investment 
itself. ... It is becoming more and more apparent in the course of irriga- 
tion development in the West that the waters of the streams should not be 
made the subject of private property, but they should inhere in the land to 
which they are applied, and that purchase or sale of water as a commodity 
should not be allowed. Although in most States the contrary doctrine has 
hitherto prevailed, the disposition of the courts at present and the views 
of practical irrigators seem to incline more and more to the doctrine of 
the public character of all streams. ... It is clear that this principle can 
best be promoted, so far as stored waters are concerned, by having the 
storage-works public property. A proper development of a storage system 
for the waters of Western streams, it is thus seen, cannot be expected 
through private agencies. It must be accomplished through some form of 
public control." 

The writer then shows that the irrigation district system of public con- 
trol, though theoretically advantageous, has practically failed, and though 
the system may be improved, it could not be sufficiently comprehensive to 
produce best results. The question is thus resolved to State and national 
agencies as the only ones qualified to deal with or create a comprehensive 
reservoir svstem. He concludes that " the work is distinctlv interstate in 
character, and is therefore less properly a State than a national enter- 
prise. Already the interstate character of some of these streams is giving 
rise to troublesome questions, which only Federal authority can answer. 
In the case of reservoirs it not infrequently happens that some of the very 
best sites are to be found close to State lines, where the waters so stored 
will flow immediately into neighboring States. In these extreme cases the 
States where they are located could not, of course, be expected to construct 
reservoirs, and the States to be benefited would not be likely to go outside 
their own borders to do so. The function clearly pertains to that sov- 
ereignty which covers all the country and embraces the streams from their 


sources to the sea. It alone can store these waters and be sure that it is 
reaping the full benefit. 

" Another reason why the government should have an interest in this 
work is that it is the largest landowner in the arid West. In Wyoming 
over 90 per cent of the soil belongs to the government, and its holdings 
throughout the West include millions of acres which can be reclaimed from 
their present desert condition and made |)roductive lands. In this respect 
government assistance in providing water for irrigation is a simple busi- 
ness proposition for the enhancement of its own property.^' 

In summarizing the arguments of which but brief extracts have been 
given in the foregoing, Capt. Chittenden draws conclusions from which 
the following extracts are taken: 

"Reservoir construction in the arid regions of the West is an indis- 
pensable condition to the highest development of that section. It can be 
properly carried out only through public agencies. Private enterprise can 
never accomplish the work successfully; as between State and nation, it 
falls more properly under the domain of the latter. 

" Eeservoir construction by the General Government need not in any 
way involve government control of irrigation-works. These should be 
left in the hands of the States and private individuals under State laws. 

" The total extent of a reservoir system in the arid regions which shall 
render available the entire flow of the streams will not exceed 1,161,600,- 
000,000 cubic feet. If the construction of such a system were to consume 
a century in time, it would represent an annual storage of 266,300 acre- 
feet. At $0.73 per acre-foot this would cost $1,430,031 per annum. This 
amount distributed among the seventeen States and Territories of the 
arid section gives an average annual expenditure in each of $84,119. The 
annual value of the stored water would return the original cost and main- 
tenance in an average period of three years." 

The latter statement is based on the estimate that the future average 
annual value of stored water for irrigation alone throughout the arid West 
is not less than $2 per acre-foot, which is certainly conservative. 

Government Regervoir Surveys in Arizona. — The waters of the Gila 
River in Arizona have been used for irrigation by the Pima and Maricopa 
Indians from time immemorial, on the lands now included within the 
limits of the Gila River Reservation. They are peaceable, pastoral tribes 
of Indians, accustomed to derive their livelihood from the cultivation of 
the soil. Within the past decade, however, the settlement of the upper 
valleys of the Gila by white farmers has been followed by such a complete 
diversion of the summer flow of the stream on the irrigated fields above 
that the Indians have been practically deprived of their accustomed water- 
supply, and reduced to a condition of dependence upon the government 
for bare subsistence. In response to an urgent appeal on their behalf made 


by the Indian Agent and the Commissioner of Indian Affairs to the 
Secretary of the Interior, an investigation was made in 1896 by Mr. 
Arthur P. Davis, of the U. S. Geological Survey, of the feasibility and 
cost of building storage-reservoirs to supply the Indians. The sites ex- 
amined and reported upon were the Queen Creek site, and a site on the 
main Gila Kiver at the Buttes, 14 miles above Florence. 

The lack of suitable apparatus for determining the depth to bed-rock 
at these sites led Mr. Davis to recommend that " thorough exploration 
should be made with a core-drill before beginning the construction of the 
dam.^' July 1, 1898, an appropriation of $20,000 was made to continue 
the investigation, the money to be expended by the Director of the U. S. 
Geological Survey, under the direction of the Secretary of the Interior. 
The work was placed in the hands of Mr. Davis, and the investigation 
thoroughly outlined by him, the writer acting as Consulting Engineer; 
but before the field-work was completed, Mr. Davis was obliged to resume 
his studies of the water-supply of Central America with the Isthmian 
Canal Commission. The responsible oversight of the work was then in- 
trusted to Mr. J. B. Lippincott, whose report was published as Xo. 33 of 
" Water-supply and Irrigation Papers." The report of the writer as Con- 
sulting Engineer was transmitted to the TJ. S. Senate, as Document No. 
152, 56th Congress, 1st Session. 

In conducting these investigations the depth of bed-rock at the various 
sites selected was tested by two machines, which had been successfully 
used on the Nicaragua Canal, and were loaned by the Nicaragua Canal 
Commission for the purpose. The machine consisted of a light, portable 
pile-driver, by which pipe from 2 to 4 inches diameter could be driven 
through sand, gravel, and bowlders, to bed-rock, with a diamond core-drill 
for penetrating the rock and bringing up a core for testing its quality. The 
cost of each outfit delivered in Arizona was about $1600. Six men were 
required to operate each machine which was capable of boring 200 feet 
in rock, and making 6 to 8 feet per day in hard rock, and 10 to 15 feet 
per day in softer rock. The average cost per foot of drilling done was 
$2.46. The entire Amount of drilling done was 3254 feet, of which 322 feet 
was in rock. Five dam-sites were thus tested, as follows: Queen Creek, 
The Buttes, The Dikes, Riverside, and San Carlos. 

The maximum depth to bed-rock at the Buttes site was 123 feet, while 
at the Riverside and San Carlos sites the greatest depth was found to be 
about 75 feet below the surface. 

The net results of the investigation are summarized in the following 
conclusions taken from the report of the writer: 

" 1st. That a minimum of 40,000 acre-feet of water annually should be 
stored for the supply of the Indian reservation. 

'^2d That it is not feasible to obtain this supply from Queen 


Creek, although the dam and reservoir proposed on the stream are feasible 
of construction if a sufficient water-supply were available. 

" 3d. That the Gila Eiver is the only available source of permanent 

"4th. That it is not feasible or advisable to build a dam and reser- 
voir on the Gila for storing so small a quantity as 40,000 acre-feet of 
capacity on account of the rapidity with which a small reservoir must be 
filled with silt. 

" 5th. That it is not feasible to construct a reservoir outside of the 
immediate channel of the Gila of sufficient capacity to provide for the 
wants of the Indians, filling the same annually by a conduit from the 

" 6th. That it is not advisable to build a dam and reservoir on the 
channel of the river of less capacity than one-half the total annual flow 
of the river in minimum years. 

" 7th. That feasible reservoir- and dam-sites exist on the Gila at the 
Buttes, Riverside, and San Carlos. * 

" 8th. That it is not feasible to build a masonry dam at the Buttes on 
account of the rotten quality of the rock, the great depth to bed-rock, 
and the excessive height of dam required to obtain a storage of 174,000 
acre-feet, or about one-half the minimum flow of the stream. 

" 9th. That a combination rock-fill and masonry dam is feasible to 
construct at the Buttes at a cost of $2,643,327, storing 174,040 acre-feet, 
but that it is not feasible to construct a dam of any type of greater height 
or capacity. 

" 10th. That the Buttes reservoir of the stated capacity may be ex- 
pected to fill with solid matter in eighteen years, unless dredged or sluiced 

" 11th. That it is feasible to construct a masonry dam at Riverside at 
a cost of $1,989,605, including damages for right oif way and the cost of 
diversion-dam at the head of the Florence Canal, forming a reservoir with 
a capacity of 221,134 acre-feet. 

" 12th. That it is feasible to increase the height of the Riverside dam 
at least 70 feet higher than the one estimated upon, giving an ultimate 
reservoir capacity of about 650,000 acre-feet, which would not be filled 
with solid matter short of sixty-seven years. 

*^ 13th. That it is feasible to construct a masonrv dani at San Carlos 
at a cost of $1,038,926, including damages for right of way and the cost of 
new diversion-dam at the head of the Florence Canal, forming a reservoir 
of 241,396 acre-feet capacity; that the water-supply is ample to fill such 
a reservoir in the years of minimum flow, and that the volume of storage 
will irrigate at least 100,000 acres in addition to the irrigation of the lands 
of the Indians. 




< Q 

i « 

ttoz 5 *^ 


























































Confeur interval 10 f«a* 


I OF Uasonbt. Oila 

as ~' 


FiQ. 192.— Sah Cablob-dah, Arizona, Bectioh thhodoh Bpillwat. 


" 14th. That it is feasible to construct a dam at San Carlos at least 70 
feet higher than that contemplated in the estimates, forming a reservoir 
whose ultimate capacity would be approximately 550,000 acre-feet, and 
whose probable life of usefulness would be sixty-three years before be- 
coming filled with silt." 

Unquestionably the best dam-site yet discovered is that located in the 
narrow canyon immediately below the San Carlos Apache Indian reserva- 
tion. The walls of the canyon are but little more than 100 feet apart at 
the level of the river-bed, and are composed of hard limestone, the lowest 
stratum being a pink color, and the upper layers dark gray, both of high 
specific gravity, and affording very satisfactory foundation for a high 
masonry dam. The maximum height of dam planned for this location 
from deepest bed-rock to the top of the central portion of the dam is 216 
feet, and the maximum length, including spillways, is 617 feet. The 
spillway on the left bank is excavated almost wholly out of the solid cliff, 
and is 128 feet in length. That on the opposite side of the dam is 237 feet 
in length, and is approached by a channel excavated largely from the 
mountainsides. The rock from these spillways will be used in constructing 
the dam. The central portion of the dam is 236 feet long, and is raised 
12.5 feet above the crest of the spillways. The latter have a discharging 
capacity of 57,000 acre-feet at that depth. Three feet additional depth 
would give a discharge of 79,000 second-feet over the spillways and 1000 
second-feet over the body of the dam, which is so greatly in excess of the 
probable volume to be cared for in flood, owing to the equalizing effect 
of the large reservoir above, that no water will, in all probability, ever 
pass over the central portion of the dam. The section, however, has been 
planned heavy enough to withstand the shock of any overflow that may 
occur in addition to the normal water-pressure. The crest width is to be 
16 feet, and the extreme base 183.6 feet. 

It is proposed to construct the dam of concrete masonry made with 
Portland cement ground with silica and to constitute what is known as 
" sand cement," as the binding material, which will be used with sand and 
broken stone in the usual manner. In the body of the concrete, large 
blocks of stone will be embedded as closely together as possible consistent 
with a perfect ramming of the concrete. The lines of pressure, with 
reservoir full and empty, are well within the inner third of the dam, result- 
ing in a safe gravity structure. Expansion and contraction are provided 
for by arching the dam up-stream. The maximum pressure on the down- 
stream toe is computed at 12.5 tons per square foot, and at 12 tons per 
square foot on the upper toe. 

The outlets to the dam are to be made throufi:h two semicircular 
towers. The intakes into the towers are a scries of elbows, with plain cap 
or cover, six in number to each tower, each 3 feet in diameter. 

Pio. 152a,— 8am Carlos D&ii-site, lookiho Down-stkeam. 

Fro. 153. — BoniNo Appauatcs. coksistiko of Pilb-dkiter and Diauosivcore 
Drill at Work. Ubbd for testing Bkd-hock at Oila Kiter Dah-sitbs, 

Fi«. 1&4.— ViKW OF THE San Cakias Dam-bite, Gila Rn-EB. Akizona. 

Fio. 151a.— View ov Left Abutment Wai.i,, Sax Caklos Dam-sitk, SHOWiNa 


Pio. 156a.— BuTTEfi D&u-siTB, ixwkiko Up-btream f 


From each tower two 48-iDch pipes pass through the dam, discharging 
into the river-bed below. These are controlled by balanced valves placed 
inside the tower. 

The reservoir will cover an area of 6230 acres at the 130-foot contour 
above river-bed at the dam, to a mean depth of 39.29fc of the maximum. 
This will be entirely on the Apache Indian reservation, and will flood 587 
acres of land that has been irrigated and farmed by the Indians. Of the 
remaining area, 4405 acres are irrigable and 3360 acres cannot be tilled. 
An abundance of equally good land on the reservation can be provided with 
facilities for irrigation above the reservoir-site. The estimate includes 

Fio. is?.— ViBw" OF RivBHsiDB Dam-bitb, Gila Rtver, Abizoha. 

$20,000 for these substitute works. The removal and reconstruction of 
the buildings of the Indian agency is estimated to cost $60,000, and the 
rebuilding of five miles of the Gila Valley, Globe and Xorthcrn Railway 
is estimated at $50,000, including the removal of two bridges. The entire 
cost of the dam and the contingent expenses noted, including the cost of 
new head-works for the canal to convey water to the reservation, located 
on the river, 60 miles below, is estimated at $1,038,026, or $4.30 per acre- 
foot of storage capacity. 

For the details of the entire system of proposed reservoirs on the 
Gila River the reader is referred to the able and interesting report of 
Mr. J. B. Lippincott, M. Am. Soc. C. E., in " Water-supply and Irrigation 



¥ia. 158.— Plan of Tonto Dam. 



Papers," So. 33, from which the cuts illustrating the plana, prepared by 
Mr. J, H. Quinton, M. Am. Soc. C. E., in collaboration with the writer and 
Mr. ]>ippincott, have been obtained by courtesy of the Director of the 
U. S. Geological Survey. 

The manifest duty of the government to provide a water-supply for the 
impoverished and dependent Indians, which will enable them to become 
again self-supporting, has been used as a lever to commit the government 
to the policy of reservoir-construction in the arid West, and it is hoped 
by the advocates of this policy that the entering wedge will be formed 
by the constniction of the San Carlos dam on the Gila. It has been shown 
by Mr. Lippincott's report that sufficient water may be impounded by the 
dam to irrigate over 100,000 acres of valuable land belonging to the 

Fio. 159.— Srctioks of Dam asd Canton of Tonto IIesbbvois. 

government, in addition to supplying the Indians, the value of which, with 
6uch permanent water-rights, will exceed $5,000,000. In addition the ex- 
pense of feeding the Indians, amounting to $109,500 per annum, would be 

The relative estimates of the cost of the dams reported upon on the 
Gila River show that the Buttes dam would cost $15.19 per acre-foot; the 
Riverside dam, $9.01 per acre-foot; and the San Carlos dam, $4.30 per 
acre-foot of storage capacity. 

Tonto Basin Sam, Arizona. — Of all the reservoir projects for irrigation- 
storage in Arizona, the largest and most extensive is that of building a 
high masonry dam on Salt Biver, and converting the great Tonto Valley 



into an enormous reservoir, covering 14,200 acres and impounding over 
one million acre-feet of water. The dam projected will be 200 feet in 
height above the ordinary low-water level of the stream (Figs. 158 and 159). 
The extreme height of the dam above its foundation will be 250 feet, and 
its length on top will be 647 feet, measured on the arc of its curvature up- 
stream, which is to be on a radius of 818.5 feet. 

The scheme is projected by the Hudson Canal and Reservoir Company 
of New York, and is a combined irrigation and elcctric-power project, the 

same water being used for both purposes. The estimated cost of the 
reservoir and dam, capable of storing water for the irrigation of 500,000 
acres of land, is $2,450,000, The cost of the electric plant and transmis- 
sion lines for developing and delivering G7G8 H.P. is estimated at 
$1,152,000, a total of $3,COS,000, including interest on capital invested 
during construction. The estimated net revenue, based partly on actual 
contracts, ia $1,134,000 per annum, of which $560,000 would be derived 
from the sale of water to canal companies and new lands in the lower Salt 
River and Gila River valleys, and the remainder from the sale of power to 
mining companies. 



The outline of the reservoir (Fig. 160) is mapped only to the 180-foot 
contour, and the ultimate height of the water-level will cover a much greater 

surface than is shown by the map. Mr. A. P. Man, Chief Engineer of the 
company, by whose courtesy the plans and maps have been made available 
for this work, furnishes information as to the hydrography of the basin, 
from which the following data are compiled: 

The area of the watershed above the dam is 6260 square miles; the 
elevation of the base of the dam at low-water level is 1925 feet above tide- 
water. The maximum altitude of the watershed is about 7000 feet, and 
the mean precipitation upon the shed is estimated at 23 inches per annum. 
The run-ofif for seven years has been computed as follows: 














The mean of these seven y%ars would represent about 15 per cent of a 
mean precipitation of 23 inches. The maximum flood yet recorded, that 
of February, 1891, was 180,000 second-feet for 24 hours. This would 
have filled the spillways to a depth of 22 feet, while the crest of the dam 
is intended to be 13 feet higher than this miximum-flood height. Maps 
of the region to be irrigated by the water from this reservoir are given in 
Figs. 163 and 164. 

The mean annual run-off from the Salt River basin has been computed 
from the records of gaugings made of the streams at 177 acre-feet per 
square mile of watershed, while the flow of the Gila above the Buttes 
averages but 26 acre-feet per square mile of shed. The difference is doubt- 
less due to the great elevation of the Salt River shed. 

The project is regarded with great favor by all irrigators in the lower 
Salt River valley, for the reason that their present supply from the normal 
flow of the river is often greatly diminished in midsummer and early fall, 
so that the full productive capacity of their lands can only be reached by 
having a supply of stored water to draw upon during the low-water stages 
of the river. The canal companies are eager to purchase all the reservoired 
water to insure a constant supply. The reservoir company is thus in the 
fortunate position of being able to sell their water at wholesale to an es- 
tablished community of irrigators, who are in urgent need of the supple- 
mentary supply. This is a rarely favorable position for a private enter- 
prise. The majority of such large projects have to meet with the long 
delay incident to the settlement of the country, which they are to provide 
with water before any adequate revenue can be derived from it. During 


this period of waiting the interest account accumulates, and if this cannot 
be met, the enterprise, though intrinsically meritorious, is destined to 

Projected Beservoirs on the Eio Verde, Arizona. — The Rio Verde, which 
has a watershed of 6000 square miles above its junction with the Salt 
River of Arizona, supplies a large surplus flood flow, which the Rio Verde 
Canal Company is organized to utilize as far as possible. The principal 
reservoir-site is located some 40 or more miles above the mouth of the 
stream, and is called the " Horseshoe reservoir," where a dam 170 feet in 
height will close a reservoir of 205,000 acre-feet capacity (Fig. 1G5). The 
length of this dam will be 1250 feet on top, the length at the stream-bed 
being 360 feet. Soundings taken along the line of the dam indicate that 
the greatest depth to bed-rock is 24 feet below low-water line, which will 
therefore make the extreme height of dam 194 feet. A spillway 1000 feet 
long, over a solid rock ledge, located 2200 feet away from the dam, is a 
commendable feature of the work. 

The elevation of the top contour of the reservoir is 2052 feet above 
tide-level, and it covers an area of 3402 acres. Water released at the dam 
will flow down the river-channel for 25 miles to a diverting-dam, 70 feet 
high and 480 feet long at the crest-line, of which the elevation is 1614 
feet above sea-level. Both dams are of the same type — rock-fills with a 
facing of asphaltum concrete. A canal with a capacity of 800 second-feet 
starts at the lower dam and skirts the northern edge of the Salt River 
Valley, practically parallel with the Arizona Canal, but extending far be- 
yond the lower end of the latter. It is to be 69 miles in lencrth, of which 
25 miles, from the mountains to Cave Creek, are practically completed. 
The outlet-tunnel to the Horseshoe reservoir, 715 feet long, through solid 
granite rock, is also finished. It is 12 f^et wide and 13 feet high, and has 
a gate-shaft near its upper end for controlling the supply to the canal. The 
estimated cost of the work is as follows: 

Horseshoe reservoir $600,000 

Diverting-dam 200,000 

Main canal to Xew River 560,000 

Extension of main canal, 19 miles 180,000 

Miscellaneous 60,000 

Total $1,600,000 

The area of tillable land above the highest canals that would be irri- 
gated by the works herein mentioned (which are only those noted in the 
company's prospectus as the works to be built on " Initial Construction '') 
is given as 220,000 acres, of which 15,000 acres are in the Verde Valley and 




Fkg. 166wMap of Lowbb Portion of McDowell Bfi&sRYOiB. 


may form a part of another reservoir to be built by the Arizona Improve- 
ment Company, 110,000 acres are between old Fort McDowell and the 
Agua Fria River, and 95,000 acres are west of the Agua Fria. 

The plans of the company also contemplate the construction of the 
following: A reservoir on New River, to be fed by the canal and the rather 
limited drainage of the stream, and to have a capacity of 133,500 acre-feet, 
covering 3-416 acres; " Reservoir No. 3," covering 1000 acres, with a 
capacity of 10,000 acre-feet; and " Reservoir No. 4,^' with an area of 2493 
acres and a capacity of 68,093 acre-feet. The cost of these is not included 
in the above estimate. The entire system will cost from $3,000,000 to 
$4,000,000. All of the dams proposed are to be of the rock-fill, asphaltum*- 
covered type. 

The company proposes to guarantee to the irrigators, in their water- 
right contracts, the delivery to them of 2 acre-feet per acre, if demanded, 
in any one irrigating season; if more water is required, it will be paid for 
extra, and the company does not guarantee to furnish it if there is a 
shortage. The annual rates are to be on a sliding scale of increase up to 
the eleventh year, when the maximum will be $2.42 per acre-foot, the first 
two years being one-half that rate. Water-rights are sold at $10 per acre, 
of which $1 is paid down and $1 per acre per annum thereafter until fully 
paid, with 8 per cent interest on deferred payments. 

McDowell Beservoir Project, Arizona. — The Arizona Improvement 
Company, the owner of the Arizona Canal, which heads in Salt River half 
a mile below the mouth of the Verde, has in contemplation the erection of 
a storage-reservoir dam a short distance above the mouth of the Verde, 
on the Verde River, to afford a means of fortifying their canal during low- 
water periods. The reservoir (Fig. 166) will flood a large part of the 
abandoned military reservation of Fort McDowell, from which it takes its 
name. The capacity of the reservoir is computed by Mr. F. P. Trott, 
county surveyor, of Phoenix, as 15,000,000,000 cubic feet, or 344,350 acre- 
feet. The height of dam proposed is 140 feet; extreme length, 1594 
feet. A spillway, 800 feet long and 10 feet deep, will be excavated in the 
crest of a ridge of rock east of the dam. The computation of contents is 
made from a contour-line run at 114 feet above the low-water level at the 
dam, or 1430 feet above tide. Bed-rock is exposed across the site with 
the exception of 200 feet, where soundings made with rods locate it at a 
depth of from 1 to 22 feet below the surface. Plans for the dam have not 
been definitely adopted, and no estimates of cost have been made. 

Bear Canyon Dam, near Tucson, Arizona. — The Santa Catalina range of 
mountains, a few miles north of Tucson, Arizona, reaches to an altitude 
of over 10,000 feet, in the culminating peak called Mt. Lemon. From the 
southern slopes of this mountain two torrential streams of considerable 
magnitude at times debouch into the valley 12 miles from Tucson. These 


are called Bear and Sabina canyons. The Catalina Reservoir and Electric 
Company, of Tucson, has projected a high dam in Bear Canyon, to impound 
the waters of these streams, diverting a fork of Sabina into the reservoir. 
The dam will be of masonry, 200 feet in height, and will require about 
50,260 cubic yards of masonry to construct it. The width between the solid 
granite walls of the canyon is but 20 feet at base, 130 feet at the 50-foot 
level, 230 feet at the 100-foot level, and 435 feet at the crest of the dam. 
The wall will be arched up-stream on a radius of 400 feet. The reservoir 
will cover 214.8 acres, and impound 14,762 acre-feet of water. The outlet 
will be placed 50 feet above the base of the dam, discharging into a cement- 
pipe conduit, 32 inches diameter, 3.65 miles long, laid on a grade of 3 feet 
per 1000. This pipe will connect with the head of a steel pressure-pipe, 
22 inches in diameter, 5000 feet long, laid down the slope of the mountain 
to the power-house, with a total drop of 1470 feet. This fall will be utilized 
to generate power, which will be transmitted electrically to Tucson and 
vicinity, where it is worth $150 per H.P. per annum. The average available 
power to be delivered for sale is estimated at 2445 H.P. 

The water will be used for irrigating land in the vicinity of the power- 
house to the extent of about 4000 acres. 

The cost of the project is estimated by the writer as follows: 

Masonry dam ; $596,530 

Power conduit 81,210 

Pressure-pipe 45,764 

Power-stations and transmission-lines 120,340 

Total .$843,844 

The net revenue is estimated at about $100,000, on the basis of using 
but one-half the storage capacity of the reservoir in any one year. 

The elevation of the base of the dam above sea-level is 4200 feet. 

Proposed Beservoirs on the Rio Grande. — The El Paso International 
Dam. — The impounding of water on the Rio Grande River at El Paso, 
Texas, has long been discussed as an international enterprise to be jointly 
entered into by the governments of the United States and Mexico for the 
purpose of making a division of the river for irrigation purposes on either 
side of the international boundarv. The Mexican authorities have claimed 
a grievance against the American people on account of the absorption of 
the stream in Colorado and New Mexico, by means of which their irrigation- 
supply has in recent years been greatly impaired and diminished, and repre- 
sentations have been made to the effect that the stream should be either 
permitted to flow as it was wont to do when the Mexican canals were first 
used, or that the flood-waters should be impounded by a reservoir of large 
capacity at the expense of the American people, and the wonted supply 


freely furnished to the Mexican canals as of yore. A survey of a mammoth 
reservoir-site was made in 1889 by Major Anson Mills, U. S. Engineer 
Corps, the site of the dam being located a short distance above El Paso,, 
in American territory. A masonry dam was here proposed, to be 65 feet 
high above the river-bottom, the construction of which would create a 
reservoir 14.5 miles long by 4 miles maximum width, with a surface area of 
26,000 acres, an average depth of 23.6 feet, and a capacity of 537,000 acre- 
feet. The estimated cost is a little over $300,000, to which must be added 
the cost of removing the tracks of the Southern Pacific and the Atchison, 
Topeka and Santa Fe railroads, which traverse the basin for a number of 
miles below the water-level, and their reconstruction on higher ground, 
above the flow-line. This was estimated to cost $590,000, while the lands 
overflowed were valued at about $69,000. The total investment would 
therefore be about $1,060,000. This work has never been undertaken. 

The Elephant Butte Dam. — Other sites for water-storage in large vol- 
ume were known to exist in the Rio Grande Valley between San Marcial 
and El Paso, and in 1890 two of them were surveyed and segregated by the 
U. S. Irrigation Survey. They are described in the 18th Annual Report 
of the U. S. Geological Survey and fire designated as reservoir-sites Nos. 
38 and 39. Site No. 38 forms a lake of 5540 acres, having a storage ca- 
pacity of 175,000 acre-feet, with a dam 80 feet high. The length of the 
reservoir is 21 miles, its maximum width a little less than 2 miles, and its 
mean depth 31.7 feet, or 39.5% of the maximum. The dam-site is located 
in rock. 

Reservoir-site No. 39 is in Paradise Valley, some 25 miles above Rincon, 
and is of little value, as the dam-site is without rock foundation. A dam 
40 feet high to the water-line would here form a reservoir covering 6380 
acres, with a capacity of 102,000 acre-feet, having a mean depth of 16 feet- 

Nearly midway between these sites is the location selected by the Rio 
Grande Dam and Irrigation Co. for the erection of a masonry dam called 
the Elephant Butte, from its proximity to a well-known landmark on the 
river by that name. This corporation was organized in 1893, and its prin- 
cipal offices and stockholders are in London, England. The plans of the 
company are very comprehensive and contemplate the irrigation of the 
Val Paraiso above Rincon, the Mesilla Valley, reaching from Fort Selden 
to El Paso, and the lands below El Paso on the Texas side of the border as 
far down as Fort Quitman, Texas, in all some 230,000 acres. Thus the 
principal areas covered by Reservoir Site No. 39, and the reservoir basin 
of the International dam above El Paso, are proposed to be irrigated. Of 
the total area of 230,000 acres proposed to be watered, it is estimated that 
48,300 acres are now irrigated, but in a somewhat uncertain and intermit- 
tent fashion, from lack of storage facilities for equalizing the flood-flow. 
The construction of the reservoir is expected to provide facilities for the 


complete irrigation of these lands as well as the larger areas of fertile, 
nntilled valley soil commanded by the new system. 

The Elephant Butte dam is located 112 miles above El Paso at a point 
where the river enters a narrow canyon, 300 feet in width between sand- 
stone walls, at the level of the river-bed. On the right bank the wall rises 
iibruptly 250 to 300 feet above the river, while on the left the height is 95 
feet to a flat bench, 450 feet wide, which is to be utilized as a spillway. 
The dam will be 100 feet high, the crest being 10 feet thick in center and 
16 feet thick at abutments. The thickness of the base will be 63.5 feet at 
center and 66.5 feet at the sides of the stream-bed. The length will be 
570 feet, on a curve of 637 feet radius, at the upper face, which will be 
lertical. The bed of the canyon at the site is covered with large limestone 
bowlders, but the surface indications lead to the belief that solid bed-rock 
will be found not deeper than 10 feet below the top of these bowlders. 
The elevation of the dam is 4325 feet above sea-level at the crest. 

The dam is estimated to contain 49,980 cubic yards of rubble masonry 
-and 1005 cubic yards of concrete, and to cost $281,515, including founda- 
tions, outlet-pipes, sluice-gates, and valves. The spillway is designed to be 
cut in solid rock, 450 feet wide, with a sill placed 15 feet below the crest 
of the dam. The capacity of the spillway is computed at 108650 second- 
feet, at 10 feet in depth, which is regarded as ample, in view of the fact 
that the maximum recorded discharge of the river at El Paso is less than 
17,000 second-feet. 

The outlets of the dam are planned to have a maximum discharging 
•capacity of 1200 second-feet, and consist of ten cast-iron pipes, 40 inches 
in diameter, passing through the dam at the bottom, in parallel lines, 6 
feet apart between centers. These pipes are reduced at the upper end by 
short reducers to 30 inches in diameter at the gates. The gates are to 
consist of hinged flap-valves of cast iron, resting on seat-rings of bronze, 
and are to be raised by iron screws reaching to the top, the motion of the 
valve extending over an arc of 90**. An ingenious cylinder for controlling 
the motion of the valve and preventing it from suddenly opening or closing 
by the eddying currents of outrushing water is attached to the valve in the 
form of a quadrant, with a loose-fitting piston which allows water to 
escape from the cylinder slowly. Between each of the gates a pilaster is 
built the full height of the dam, eleven in all, projecting from its face 5^^ 
feet. These pilasters are grooved near the outer face, sufficiently to receive 
a series of loose flashboards, or check-planks of cast iron, which slide up 
and down in the grooves. When these check-planks are in place they form 
open chambers from top to bottom, called penstocks, which separate the 
water supplied to each gate from the others. These penstocks are 2 X 3 
feet in dimension, and are lined throughout with cast iron. The water 
enters them by overflowing the top of the check-planks, of which a suf- 


ficient number are left out to give the required depth of overflow. As the 
reservoir lowers, additional planks are removed. When these planks are 
placed so as to reach above the level of the water each penstock forms a 
shaft, through which a man can descend to the gate below to make repairs. 
The check-planks are 2 feet square, and rest on bronze seats. They are put 
in place and removed by a carriage sliding down in the same grooves, and 
provided with automatic clutches that engage in lugs cast upon the sides of 
the planks, near the top. This carriage is hoisted and lowered by means of 
a geared hand-hoist, placed over the penstock at the top of the dam. The 
plan thus contemplates drawing ofiE water from the top of the reservoir at 
all times. 

An alternative plan provides for closing the pipes by means of circular 
gates fitted with roller bearings to reduce friction. These can be raised 
entirely to the top and removed if desired. 

On Fig. 167 is shown a plan of the dam-site locating the position of 
the dam and spillway, a profile of the masonry structure designed with 
lines of pressure, reservoir full and empty, and a cross-section of the dam- 
site and spillway. 

The Reservoir. — The reservoir formed by the dam is 25 miles long on 
the 75-foot contour, covers an area of 7965 acres, and has a capacity of 
253,368 acre-feet. (See Fig. 168.) It reaches to the dam-site of the U. S. 
Bes. Site No. 38. Of the lands embraced in the reservoir, 2549 acres are 
public lands, while those in private ownership cover 5416 acres and arc 
valued at $7517. 

The dip of the rock strata is toward the river from each side. The 
sandstone when tested developed a weight of 147 to 160 lbs. per cubic foot, 
and a crushing-strength of 216 to 360 tons per square foot. 

From the dam the water will be released into the channel of the river, 
which it will follow for 6 miles to a diverting-weir at the head of Paradise 
Valley. This weir is to be built of rubble masonry, faced with cut-granite 
blocks, and have 300 feet of overfall for the passage of floods. • Here are 
placed the head-gates of a canal to be constructed for the irrigation of 
40,000 acres of Paradise Valley, in a solid rock cut, affording rock for the 
construction of the dam. 

Below Paradise Valley the river is again inclosed in a rocky canyon, 
near the lower end of which a second diversion-weir is located, the con- 
struction of which has begun, as shown in Fig. 169. This dam is 5^ miles 
above Fort Selden, N. M., and about 50 miles below the storage-reservoir 
at Elephant Butte. Its purpose is merely the diversion of water for the 
irrigation of the Mesilla Valley, extending from Fort Selden to El Paso. 
It is a concrete structure, combining an overfall waterway for the passage 
of the river, and head-gates for the canal. The height of the crest of the 
overflow-weir is 5 feet above the river-bed, or the exact depth of the water 



























in the canal^ whose grade is coincident with the bed of the river. The 
length of the weir-channel is 300 feet. The thickness of the concrete at 
base is 20 feet, and the crest is in the form of a rollerway curve. The 
abutments are 7 feet high above the crest of the weir. The water is ad- 
mitted to the canal through six cast-iron pipes, 48 inches diameter, set in 
a concrete wall, and closed with sluice-gates. The entire structure, includ- 
ing wing walls and abutments, is founded on piles, driven by hydraulic 
jet into the sand bed of the river, and inclosed with triple-lap sheet-piling 
above and below. Fig. 169 gives a view taken during construction. The 
weir is estimated to contain 2450 cubic yards of concrete and to cost 

A third diversion-weir, to be built of masonry on bed-rock foundation, 
is also contemplated for the supply of canals below El Paso, the location 
selected being the site of the proposed " international dam," 5 miles above 
El Paso. It is believed that the latter structure, as originally contem- 
plated, will never be built, but that the Elephant Butte dam, when finished, 
will serve as an efficient substitute, at less cost, and without interference 
with the railways. 

Some 200 miles of main canal and primary laterals are projected from 
the two diversion-weirs above El Paso. The entire enterprise is estimated 
as follows: 

Elephant Butte storage-dam $281,515 

Diversion-weir, 6 miles below 27,874 

Diversion-weir, 50 miles below 19,653 

Canal svstem above Rincon, N. M 75,749 

Canal system in Mesilla Valley 249,682 

Canal system below El Paso 196,000 

Total $850,473 


This is an average cost of $3.70 per acre for the 230,000 acres to be 
sxipplied with water, altho\igh the estimate does not include the diverting- 
dam near El Paso. 

Construction began in 1897 with the concrete weir near Fort Selden, 
but has been interrupted by litigation. From this weir, a canal 34 feet 
wide on bottom, 5 feet deep, on a grade of 1 : 5000, was excavated 7 miles 
down the west side of the Eio Grande Valley, where it was carried across 
the river by a series of four inverted siphon pipes, 50 inches in diameter, 
laid in a trench 11 feet below the bed of the stream. These pipes are 
made of long-leafed Texas yellow-pine staves, held in place with round 
rods of steel at intervals of 12 inches from center to center. They are 
each 388 feet long, and have a fall of 3.06 feet from the water-level m the 
canal on the west side to that of the canal on the east. They pass through 


wooden bulkheads or wing walls, which confine the river on either side to 
its natural banks. They have a combined capacity equal to that of the 
cana), or 465 cubic feet per second. The plan of the crossing and the 
method of construction are well illustrated by the accompanying photo- 
graph, Fig. 170, 

The chief engineer of this work, which when completed will be one of 
the most important and extensive irrigation projects in the arid region, 
is Mr. J, L. Campbell of El Paso. 

KiQ. 170.— WooD-flTAVB Pipes, laid under Bed of the Rio Okaddr. for 


Com PANT, 

Wafer-svpply of the Rio Grande al El Paso. — Gaugings of the flow of 
the Rio Grande Kiver at El Paso, made by the U. S. Geological Survey 
and published in their annual reports since 1890, give the following data 
of the discharge of the stream: 
May 10, to Dec. 31, 1889 (no flow during the months of 

August, September, October, or November).... 367,266 acre-feet 

1890, flowing the entire year 963.466 " 

1891, January to June, inclusive 1,567,173 " 

1897, stream dry during a part of August and 

September 1,360,360 " 


From these data it is apparent that the reservoir at Elephant Butte 
vould have filled during any one of the years during which these gaugings 
were made. 

Gaugings made at San Marcial, some 50 miles above Elephant Butte, 
give the following as the discharge of the stream at that point: 

1895, February to August, inclusive 1,246,509 acre-feet 

1896, February to December, inclusive 541,499 " 

1897, February to December, inclusive 2,215,257 " 

In 1897 the stream was practically dry during August and September, 
yet the total discharge of the year was sufficient to have filled the Elephant 
Butte reservoir nearly ten times. 

In comparing the discharges given in 1897 at San Marcial with those 
at El Paso, nearly 200 miles below, one cannot but be struck with the 
enormous loss of water in the stream in traversing that distance, amount- 
ing to 854,897 acre-feet during the year, or 38.5% of the total flow. A 
small part of this may be due to the diversions for irrigation and to 
evaporation, but the greater portion must find some subterranean escape. 
A possible explanation of this source of loss is given in the following ex- 
tract from the printed report of Mr. J. L. Campbell upon the Elephant 
Butte reservoir site. He says (p. 9) : 

" Barring the existence of possible subterranean fractures, open suf- 
ficiently to carry away considerable amounts of water, the character of the 
reservoir-site topographically and geologically is peculiarly adapted for 
storage purposes." 

These fissures may, and probably will, in time be entirely closed by 
the deposit of silt in the reservoir, and thus the supply may be augmented 
by the prevention of this source of loss. 

The Silt Problem. — From 118 samples of the water of the Eio Grande, 
taken by Major Anson Mills at El Paso, the conclusion was reached that 
the silt carried in suspension averaged 0.345 of 1% of the volume, or in 
other words 1 acre-foot for each 290 acre-feet of water. The determina- 
tions of the Geological Survey during 1889 and 1890 at the same point 
show a somewhat less percentage.* It is there stated that " the total sedi- 
ment for the year ending June 30, 1890, is in round numbers 3,830,000 
tons; this earth, at a weight of 100 lbs. per cubic foot, would cover a square 
mile 2J feet in depth.'^ 

This would be equivalent to 1760 acre-feet of sediment, and as the 
discharge of the river during this period was 820,425 acre-feet, the ratio 
of silt to water is therefore as 1 to 466. A mean of these ratios would 

 llth Annaal Report, U. S. Geological Survej, Pan II, page 67. 


be 1 to 388. If^ on this basis^ all the sediment carried by the stream be 
assumed to deposit in the Elephant Butte reservoir^ it would catch but 650 
acre-feet every time its full capacity were carried through it. If the river 
carries sufficient volume to fill the 253,000 acre-feet of its capacity five 
times per annum on an average, it would require 130 years to fill the 
reservoir. Long before this result- could occur it would be profitable to 
add a few feet to the height of the dam, or construct the large reservoir 
in the adjoining basin above, or take measures for sluicing out a portion of 
the accumulated sediment. It does not appear that the silt problem is one 
which need give serious concern in this situation. 

Evaporation, — The loss by evaporation from. the surface of the reser- 
voir is estimated by the chief engineer to be 7 feet in depth per annum, 
based on the observations of the U. S. Geological Survey at El Paso during 
1889-91. From this he computes the annual loss from the reservoir at 
50,000 acre-feet, and from the surface of the canals at 22,000 acre-feet. 

Proposed Keservoirs in Texas. — In "Water-supply and Irrigation 
Papers," No. 13, published by the U. S. Geological Survey, Mr. Wm. F. 
Hutson describes some large projected storage-reservoirs on the Nueces 
Kiver, in Texas, which are important in their dimensions and of general 

The Caimanche Reservoir. — Cairaanche Lake lies to one side of the 
Nueces River, and gathers the water of a large drainage-basin extending 
from the Rio Grande divide on the south to many miles beyond the South- 
ern Pacific Railroad on the north, a region containing springs and an 
easily obtainable supply of artesian water. It is proposed to convert 
Caimanche Lake into a storage-reservoir by means of an earthen dam If 
miles in length and 20 or 25 feet in height. It will store about 132,750 
acre-feet of water at the spillway-level. In addition to the natural drain- 
age-basin tributary to the lake it is proposed to turn into it the water of 
the Nueces River by a short canal, 1| miles long, from a point called Rock 

The area of the reservoir will be about 10,000 acres. The promoters 
expect to irrigate from this reservoir about 50,000 acres of land. 

The Nueces Reservoir. — Some 45 miles below Rock Falls, on Nueces 
River, a masonry dam has been projected across the river, 2600 feet in 
length, 50 feet in height, which will form a reservoir of 12,700 acres in 
area and impound 222,250 acre-feet. 

Lower Reservoirs. — About 100 miles further dovm the Nueces, at the 
junction of Frio River and below, surveys have been made by private 
capital for an enormous system of storage-reservoirs for irrigation. These 
are fourteen in number, having a combined storage capacity of 1,792,300 
acre-feet. The two largest of these will be formed by masonry dams 
across the Nueces and Frio rivers. The total area to be brought under 


irrigation by the system of canals to be supplied by these reservoirs is 
something over 1,000,000 acres. 

Sand Lake Reservoir, Western Texas, — ^About 9 miles north of Pecos 
City, Texas, a natural basin, called Sand Lake, has been selected as an 
available reservoir-site for impounding water to be used for irrigating 
lands in the vicinity of Pecos City and Barstow. The basin now contains 
a pond of 300 acres, maintained by the run-off from the local watershed. 
The basin can be filled to a depth of 28 feet before overflowing, impound- 
ing 55,000 acre-feet and covering a surface area of 3740 acres. A dam 
on the rim of the basin, 12 feet in maximimi height, 4000 feet long, would 
increase the area to 5080 acres, and the storage capacity to 79,200 acre- 
feet. The outlet to the reservoir would require a cut 3 miles long, 18 feet 
deep, to draw off 72,500 acre-feet. The reservoir would be fed by a canal 
from the Pecos River, 23 miles long, having a capacity of 450 second-feet, 
from which the reservoir could be filled in ninety days. The total cost of 
the canal and reservoir-outlet is estimated at $130,000. 

Upper Pecos Reservoir-site. — Some 50 miles above the to^Ti of Eoswell, 
N. M., a notable reservoir-site exists on the Pecos River, where a dam 50 
feet high would impound 250,000 acre-feet of water, forming a lake 12 
miles long, 2 miles wide. The dam-site is at a point where the river has 
cut through a ledge of limestone to a depth of 58 feet on the west side and 
75 feet on the east. The cost of a masonry dam at this site would be 
about $300,000, or $2.20 per acre-foot of storage capacity. A rock-fill 
and earth dam, of the type described in a previous chapter as having been 
built lower down on the Pecos, would be about one-half the cost of a 
masonry dam. 

The area of arable, irrigable land in the valley of the Pecos between 
Eoswell, N. M., and Grand Falls, Texas, is as follows: 

Land commanded by the Pecos Irrigation and Improvement 

Co.'s canals and reservoirs 174,000 acres 

Land between State line and Riverton, Texas 15,000 

Land under the unfinished Mentone Canal, east side 36,000 

Land under the Highland Canal, west side 50,000 

Land under the Pioneer Canal, constructed 38,000 *' 

Land under the Pioneer Canal, extension 15,500 " 

Additional area below Barstow 1,500 " 

Total 330,000 


The volume of water annually passing the head-gates of the Pioneer 
Canal at Barstow, as determined from records kept for several years, is 
approximately 700,000 to 1,000,000 acre-feet. This volume is sufficient 



for the irrigation of all the lands of the valley if properly stored and 

The data concerning reservoir-sites on the Pecos Eiver are taken from 
a report hy the writer made in 1898. 

BrOck Greek Eeservoir, Nevada. — One of the tributaries of Humboldt 
Eiver, which enters that stream a few miles above Battle Mountain, Nevada, 
from the north, is known as Eock Creek. It drains a watershed of 760 
square miles, whose altitude ranges from 5000 to 13,000 feet above tide- 
level. As it debouches into Humboldt Valley it passes through a narrow 
gorge, 5 miles long, cut deeply through a volcanic range of hills, at the 
head of which is a favorable site for a dam and reservoir, as the stream 
passes through a large open valley. The capacity of this reservoir at the 
75-foot contour above the base of the dam is 80,000 acre-feet, covering 
3670 acres (Fig. 171). The canyon at the dam-site, is but 120 feet wide 

Fig. 173. — Sketch of Longitudinal Section of Lost Canton Natural Dam 

at bottom and but 300 feet at the 7o-foot level. On the left bank the 
canyon wall rises abruptly to a height of over 250 feet (Fig. 172). The 
material is a hard porphyry at the dam-site, capped at a few hundred feet 
height by a layer of basalt of great depth. The character of dam proposed 
for the site is a rock-fill, of the Pecos type, faced with an embankment of 
earth. The estimated cost of the dam is about $80,000. 

The run-off from the watershed is estimated to exceed 150,000 acre- 
feet per annum, or about 200 acre-feet per square mile. The precipita- 
tion on the shed varies from 7 inches annually at the dam, to over 40 inches 
in the higher mountain-ranges. 

Used as a needed supplement to the normal summer flow of the 
Humboldt, the reservoir is expected to irrigate about 100,000 acres of the 
valley lands, bordering the river, between Battle Mountain and Golconda. 


Lost Canyon Natural Dam, Colorado. — The region of Lost Park and 
Lost Canyon, on Goose Creek, Colorado, a tributary of South Platte River, 
is one of rugged grandeur, characterized by scenery of the wildest imagin- 
able description, abounding in high cliffs and rock-masses of fantastic 
shapes and colors and of Titanic dimensions. Xature has here made an 
effort at rock-fill dam-construction on a grand scale by filling in the 
canyon to a maximum depth of 250 feet with an aggregation of enormous 
bowlders thrown from the neighboring cliffs. This remarkable rock-fill is 

Fio. 174.— Sketch or Crobb-bectioh at Upper End of Lost Canton Natural Dah. 

2100 feet in length, and is fairly well represented in a general way by the 
longitudinal and cross sections shown in Figs. 1*3 and 1T4. The maximum 
height above the upper toe is, as stated, 2.>0 feet; hnt as the bed of the 
canyon falls 150 feet in the length nf the dam, the height of the crest is 
400 feet above the lower toe, where the stream emerges from underneath 
the bowlders. The extreme width on top is 400 feet, although the bull^ 
of the fill is less than 100 feet in width, and at the bottom the canyon width 


bbcween well-polished walls is but 20 to 25 feet^ at such places as it is pos- 
sible to go underneath and inspect it. 

Some of the bowlders that form the embankment are as large as an 
ordinary two-story dwelling-house, and the stream finds its way through 
them with little apparent obstruction, although the presence of a pile of 
driftwood at the mouth of a cave on the upper face, 150 feet above the 
bottom, is an indication that occasionally the volume is too great to find 
exit in the lower passages and is forced to rise to this higher outlet. It is 
possible to descend in this cave, by means of ladders and ropes, into the 
interior of the dam almost to the water-level. The crest of the solid mass 
of the dam proper is at the 200-foot level, although a chain of huge 
bowlders, 25 to 50 feet high, lying near together, extends across the canyon 
from side to side. The entire surface of the natural embankment is dotted 
over with large fir-trees, growing in the soil that has lodged in the crevices. 
As the stream emerges from the foot of the dam it has the appearance of 
a spring flowing out from beneath an old glacial moraine. 

Surveys of the site have developed the fact thac a reservoir with a 
capacity of 24,000 acre-feet can be made available for storage and use by 
making nature's dam water-tight. This may readily be done by filling 
the crevices and cavities on the upper face with concrete and providing a 
proper outlet for the water by means of a tunnel. 

The latter has been projected on the 75-foot level, and will require to 
be 1200 feet long to reach a neighboring canyon. The cost of this work 
has been estimated at $104,000, or $4.35 per acre-foot of storage capacity 
in the reservoir. An addition of 20 feet to the top of the dam would 
increase this capacity to 27,700 acre-feet, and the cost to $144,000, the 
work to be done in Portland-cement masonry. The reservoir has been in 
contemplation for some years as a storage for irrigation and domestic 
supply in and around Denver, from which city it is some sixty miles 

California Beservoir Projects. — Little Bear Valley Dam. — The Arrow- 
head Reservoir Company of Cincinnati, whose headquarters are located 
at San Bernardino, Cal., began construction some years ago on a masonry 
dam of large proportions which is to store water in a mountain valley, 
called the " Little Bear,'* on the head waters of the Mojave River. This 
stream flows northward into the Mojave Desert, and its water runs to 
waste. The project of the Arrowhead Company is to gather together a 
number of the tributaries of the stream above an elevation of 4800 feet, 
store the water in reservoirs and convev it across the San Bernardino 
Mountains for irrigation in the San Bernardino Valley. A contour map 
of the reservoir is shown in Fig. 175. 

The dam, of which a portion of the foundation only has been laid, is 
designed to be carried to an extreme height of 175.5 feet above the 



assumed " base ^^ of the dam, although the lowest foundations will be 20 
to 30 feet lower than the " base." The outlet-tunnel is 15.5 feet above 
" base." The dam is intended to be a monolithic structure of Portland- 
cement concrete, arched up-stream, with a radius of 550 feet to the up- 
stream face. Its top length will be 747 feet, and its base thickness 133 

The reservoir will cover an area of 884 acres and impound 60,179 acre- 
feet of water. 

The company has been at work on the main conduit leading from the 
reservoir since 1892, their efforts being directed chiefly to the opening of 



Va/Iey / 

.'SOiO ^ "" 

Bmse of Dam 

Fio. 174a.— Comparison of Dams of the System of the Arrowhead Reservoir 
Co. IN THE Ban Bernardino Mountains, California. 

the principal tunnels on the line, of which there are a number. The 
longest of these is the outlet to the reservoir, 4957 feet in length exclusive 
of approaches. This was made necessary to avoid 10 miles of canal around 
a long mountain-ridge. It has been completely lined and arched with 
concrete. Two other tunnels, 1844 and 1792 feet long, have been com- 
pleted, and are to be lined during the summer of 1900. 

The total length of conduit required to turn the water over the 
summit of the mountain-divide is 13 miles. From the summit crossing 
to the grade of the conduit at the base of the mountains skirting the 
upper slopes of the valley north of San Bernardino the total descent is 
2700 feet, which will be utilized to develop power. 


The volume of water which the company expect to develop and supply 
is 5000 to 6000 miner's inches (100 to 120 second-feet) of continuous flow 
during 200 days each year. 

The determination of the volume of supply which can he impounded 
and sold from the system has been the result of eight years of continuous 
stream measurements and precipitation records. The company maintains 
2 6. rain-gauges, located at different points on their watersheds, and a large 
number of self-registering devices for measuring the depth of overflow on 
their weirs. It is doubtful if any such systematic and intelligent study of 
probable available water-supply from the catchment of ^ood run-off prior 
to the construction of works has ever before been attempted in the West, 
and the final result must prove of great value to the company, as well as 
an invaluable addition to the general store of knowledge on such subjects 
when finally made public. 

The area of the watershed directly tributary to the Little Bear Valley 
reservoir is but 6.6 square miles, but it will be fed by a large conduit 
diverting the water from Holcomb Creek, Deep Creek, and intermediate 
streams. This conduit will consist mainly of a large tunnel from Deep 
Creek. The entire area of shed from which the system will be supplied is 
about 77 square miles, all of which is above 5000 feet in altitude, on a well- 
forested mountain-crest, and is among the most productive areas in south- 
ern California in stream run-off. The Little Bear Valley drainage-basin 
shows the greatest amoimt of precipitation and stream-flow, and in the period 
of observation has given a minimum of 600 and a maximum of 2200 acre- 
feet of run-off per square mile per annum. An intercepting-canal 13 miles 
in length, including the tunnel mentioned above, to gather the stream- 
flow from 61.43 square miles of watershed lying east of Little Bear Valley 
and empty it into the main reservoir, is an essential part of the general 
system. This canal will have a capacity of 200 to 400 second-feet, increas- 
ing as it takes in each successive stream on its way. 

Two other reservoirs are contemplated, one at Grass Valley, 4 miles west 
of Little Bear, elevation 5108 feet, where a dam 175 feet high will give 
27,547 acre-feet of capacity on a reservoir area of 382 acres; the other 
at Huston Flat, 5 miles west of Grass Valley, elevation 4450 feet. The 
175-foot contour at the latter site will give a capacity below it of 24,753 
acre-feet. This dam, being near the line of the conduit from Little Bear 
reservoir, which would pass the dam-site at an elevation of nearly 300 
feet above the 175-foot contour, could be built advantageously by the 
sluicing and hydraulic jet process, as an abundance of material for the 
purpose can be had conveniently on both sides of the canvon where the 
dam would be located. To utilize this reservoir will necessitate a tunnel- 
outlet 5900 feet long, and it has been proposed to make this tunnel a part 
of the main conduit, by which means 4^ miles of canal would be saved, the 

Fio. 1744.— View of IlnsTON Flat Rksbhvoir-bitb, one or the Bybtkm of thb 

AuHowHBAD Rbbkrvoir Co. 

Tbli dnm Is to be b»Ut b^ tlie b7dr«ullc-fl)l process. 

Heau Valley Reseuvoik. 

[Tu face page 31 i. 




height of 130 feet, at which it will have a capacity of 61,500 acre-feet, 
covering 1214 acres. Its cost has been estimated at $400,000, and the 28 
miles of canals for distribution to 40,000 acres of land at $230,000, an 
average cost for the system of about $16 per acre. 

The capacity of the drainage-basin for run-off has been demonstrated 
in a striking way on two notable occasions when floods from this section 
destroyed the Southern California Bailway through the Temecula Canyon, 
causing enormous loss and destruction of property. The track has not 
been restored since the last time it was destroyed, in 1890-91. 

Fig. 178. — ^Map of Watershed and the Lands to be inRiOATED from Victor 


Victor Dam, California, — Doubtless the most capacious reservoir pro- 
jected in California is that of the Columbia Colonization Company, located 
on the Mojave River in San Bernardino County, at the Upper Narrows, 
near the town of Victor (Fig. 178) on the line of the Southern California 
Railway, which now passes through the site of the dam, and will have to 
be rebuilt for 5^ miles to clear the reservoir. The pass at the Narrows is 
in a granite ridge, which affords most admirable buttresses for a masonry 
dam, and is a remarkable one, favorable in all respects for such a structure. 



The width at the stream-bed is but 140 feet, while at the height of 150 
feet the walls of the canyon are but 360 feet apart. Soundings have been 
taken with steel rods driven through the sand, which show the maximum 
depth to what is believed to be bed-rock at 53 feet. Fig. 179 is a cross- 
eection of the site, showing the soundings, and Fig. 180 is a view looking 

Flo. 170.— Cross- SECTION of Victor Dam-site. 

up-stream from the county bridge through the dam-site, the stakes shown 
in the water marking the positions of the various soundings. The reser- 
voir-basin is shown in Fig. 181, and Fig. 178 is a general map of the 
watershed and the lands proposed to be irrigated. 

As planned, the dam will contain about 70,000 cubic yards of masonr;. 


including the filling of a narrow gap in the rim rock above the 105-foot 
contour, some 600 feet west of the dam proper. On the opposite side 
a natural spillway of ample dimensions exists at a height of 145 feet, by 
which the waste will be returned back to the channel at a safe distance 
below over a ledge of solid granite. The reservoir at the 145-foot contour 
covers an area of 7718 acres, and has a capacity estimated at 17,000,000,000 
cubic feet, or 390,000 acre-feet, the mean depth being 50J feet, or 34.86 
per cent of the maximum. The ratio between mean and maximum depth 
in all large commodious reservoir-basins which have a fairly uniform slope 
of stream-bed from the dam-site up, and do not show a series of rapids 
for a distance above the dam, is found to range from 28 to 45 per cent, 
and it is often customary on preliminary estimates, after determining the 
area of the highest contour embracing the reservoir, and before making 
detailed survey of the interior of the basin, to apply such a percentage 
of the height of the dam for computation of contents as the engineer may 
consider safe within these limits, taking into consideration the general 
topography of the site. Such has been the method of determining the 
capacity of the reservoir in question. 

The watershed area draining out through this dam-site is somewhat 
indeterminate from lack of surveys in the eastern part, but it has been 
roughly computed as 1250 square miles, of which the drainage from the 
greater portion of 77 square miles on the mountain-crest may be diverted 
by the works of the Arrowhead Reservoir Company. The precipitation has 
a wide range of variation, from 60 inches and upward on the summits of 
the mountains to 5 or 6 inches at the dam. Measurements made by F. W. 
Skinner, civil engineer, between Januarv 1 and August 1, 1893, gave a 
maximum discharge of 8500 second-feet and a minimum of 38 second-ieet, 
from which the mean flow from August 1, 1892, to August 1, 1893, was 
computed as 825 second-feet. This would be equivalent to an annual 
run-off of 597,300 acre-feet, or nearly double the proposed reservoir 
capacity. At the same time it was noted, by the appearance of the drift 
along the banks and the statements of the residents of Victor, that the 
highest floods of that season lacked several feet of reaching the high- 
water marks of previous years. 

In connection with the laying of the foundations of the dam, it is in- 
teresting to consider the probable volume of underflow in the stream at 
this point. The area of cross-section shown by the soundings below the 
surface is approximately 4160 square feet. The rate of percolation deter- 
mined by the Agua Fria dam-construction (p. 234), if applied to this area, 
would give an underflow of 11 miner's inches; and even if this were multi- 
plied by 10, the flow to be handled by pumps during construction would be 
but little more than 4 second-feet, which is not a formidable amount to 
contemplate taking care of. 

Fig. 181.— Map of Victor Ukbervoik. 



The lands to be irrigated from the reservoir lie west of the river, be- 
tween the Southern California Railway and the Atlantic and Pacific Rail- 
road, and north of the latter. The area of good land in this region re- 
quiring water is greatly in excess of the probable water-supply. The cost 
of the entire system of storage and distribution, including canals and 
laterals delivering water to 200,000 acres, is estimated at $1,742,000, or 
$8.46 per acre, although the company states that it has secured bids from 
reliable contractors which will greatly reduce these figures of cost. It 
appears to be an enterprise which would reclaim so large an area of the 















1 "^ 


















27 ' 

b 25 






Fio. 182. — Map op Manache Meadows Reservoir. 

public domain that is now a desert as to entitle it to be classed among 
those which should be carried to successful completion. 

Since the above article was written in 1897, the U. S. Geological Sur- 
vey has made borings, in 1899, to determine the depth to bed-rock, with 
the diamond drill-core, and practically confirmed the correctness of the 
original soundings. 

Projected Keservoirs on Kern Biver, California. — A number of available 



sites for impounding a considerable volume of the flood-waters of Kern 
River have been surveyed in the mountains near the sources of that noble 
stream the "Eio Bravo of the South/' as it was known to the native 


•* e£e(/ 

* ^ ^-aa^o'^ 


Fio. 188.— Map of Manachb Meadows Dam-sitb. 

Califomias, the largest of which is in the Manache Meadows^ on the 
south fork of Kern River, at an elevation of 8200 feet above Rea-level (Fig. 
182). A rock-fill dam at this site, estimated to cost $150,000, will create 


a reservoir of 5830 acres and impound 248,850 acre-feet^ from which it is 
apparent that the site takes front rank among the most capacious sites that 
have come to public notice in the West. The locality has the appearance 
of having been a large lake in a comparatively recent geological period, 
and the basin is so flat that it is classed, and has been surveyed and 
segregated, as " swamp and overflowed land." The highest peaks in the 
catchment-area are over 13,000 feet high, and Mount Whitney, 15,000 feet 
in altitude, is drained on one side by Whitney Creek, the water of one 
branch of which can be diverted into the reservoir by an inexpensive cut. 
The area of drainage naturally tributary is 155 square miles. 

The dam-site (Fig. 183) shows solid ledges of granite on each side, and 
soundings indicate that bed-rock is but 8 to 10 feet below the surface 
across the canyon-bed, which is but 160 feet wide at the bed of the stream 
and 460 feet wide at a height of 85 feet. Lime can be burned for use on 
Whitney Creek, 20 miles distant, and there is a great abundance of timber 
which clothes all the surrounding mountains. 

The Manache Meadows reservoir-site has been located by the Kern- 
Rand Eeservoir and Electric Company of Los Angeles, with the view of 
utilizing it to equalize the flow of the stream sufficiently to enable them to 
use the water continuously for power. The fall available at the middle 
power-station is 2250 feet, which it is proposed to utilize in one drop, gen- 
erating 24,000 H.P. and transmitting it electrically to Los Angeles, 125 
miles distant. The upper station has an available drop of about 1900 feet, 
requiring a conduit of 15 miles to reach it. The lower station has a drop 
of 200 feet and would deliver water to the highest of the irrigation-canals 
in South Fork Valley. The total theoretical power available for all three 
stations is estimated at 45,870 H.P., of which about 30,000 H.P. may be 
delivered to points of intended use. 

The mountain valley of the South Fork, above its junction with the 
North Fork, has an altitude of about 3600 feet, and contains some 25,000 
acres of good arable land, of which about 15,000 acres are irrigated, chiefly 
for alfalfa. There are thirty ditches, each from 1^ to 3 miles in length, 
5 to 6 feet wide on bottom, and carrying 1 to 2 feet depth of water. The 
reservoir in the Manache Meadows would interfere with the supply to these 
ditches only during the last half of July and the months of August and 
September. During the remainder of the year the streams below the 
Meadows are adequate for this service. In fact, the Manache is but one- 
fifth the total area of the South Fork drainage above the South Fork farm- 
ing community, and probably does not supply more than 40 per cent of the 
flow of the stream. 

The main characteristics of the North and South forks of Kem River 
are as widely diflFerent as though the streams were in separate States. The 
North Fork rises in very high, rugged, and precipitous mountains on which 


the snow lies late in summer. Its canyon is a deep^ narrow gorge through- 
out its entire length, from its source to Kernville, near its junction with 
South Fork, with only here and there a narrow strip of meadow-land along 
the stream, not in any way resembling the expansive meadows and open 
plains which characterize the South Fork for so great a part of its course. 
The North Fork drains 1069 and the South Fork 754 square miles of 
watershed, but the precipitation and run-off of the two sheds vary so 
greatly that the normal flow of the former is ten to twelve times greater 
than the latter at their point of junction. Unfortunately the relative 
advantages of the two forks respecting sites for storage seem to be in in- 
verse ratio to their volume of flow and capacity for filling reservoirs. 

Kern Lake Beservoir. — One of a large number of sites surveyed in 1881 
by the State Engineering Department of California is at the " lake " on 
North Fork, where a landslide has filled the canyon some 20 feet and 
created a pond 40 acres in area. This place has been viewed with the idea 
of constructing a high rock-fill dam, to be formed by a few huge blasts from 
the cliffs that tower almost vertically above it for 2000 to 3000 feet. The 
capacity of a reservoir at this place would be 4(5,600 acre-feet at the 220- 
foot level, covering about 600 acres. The outlet would be made by means 
of a tunnel of sufficient capacity to carry the river during construction of 
the dam. The plan suggested contemplates filling the canyon for several 
hundred feet with such an enormous mass of rock as to give it unques- 
tionable stability, and after it is thrown down, to lay up a dry wall on its 
upper face and cover it with asphalt concrete, excavating a spillway en- 
tirely around the dam so created. The canyon width at the site is but 100 
feet at bottom and 400 feet at a height of 230 feet. The work is estimated 
to cost $225,000. 

One of the advantages of the reservoir in this locality would be that 
it could be filled twice a year or oftener. Experiejice has demonstrated 
that the usual shortage in supply to the Kern Valley canals occurs twice 
a year — in February and March, and in August and September. In these 
months a reinforcement of the stream is very much needed. Between each 
of these periods the North Fork reservoir could be filled and its contents 
made available for the next low stage. 

It may be considered, therefore, that the reservoir, if built and oper- 
ated in the manner suggested, would practically add 46,000 acres to the 
irrigable area of the valley, at a cost of about $5 per acre. 

Big HeadowB Beservoir. — Located on Salmon Creek, a branch of the 
North Fork of Kern River, at a point known as Big Meadows, is a site 
where a dam of 75 feet height will form a reservoir of 870 acres that 
would impound 31,150 acre-feet of water. The dam-site is in a granite 
canyon with clean bed-rock on bottom and sides, the width at bottom be- 
tween walls being but 25 feet, while the top width at the 75-foot level 


would be 390 feet. A rock-fill dam is estimated to require 26,000 cubic 
yards of material, and to cost $80,000. The area of watershed is estimated 
at 14 to 25 square miles. 

Throughout the higher Sierra Nevada are innumerable lakes of con- 
siderable area and capacity, generally so high as to be above the timber- 
line, which can be utilized as storage-reservoirs at small expense. They 
may be counted by the hundreds on the headwaters of Kings, San Joaquin, 
Merced, and Tuolumne rivers, although it cannot be said that any of them 
are so extensive or capacious as to be distinctly noticeable or require special 
description. Preparations are being made by people living in Visalia to 
utilize two such lakes on the headwaters of the Kaweah River in a some- 
what novel manner. By means of a number of 10-inch pipes they propose 
to siphon the water out of the lakes to a depth of about 20 feet, and as 
one of them, called Moose Lake, is about 300 acres in area, it is expected 
to draw from it in the season of greatest shortage about 5000 to 6000 acre- 
feet of water. The other, known as *^ Big Lake," has almost as large an 
area. This method of utilizing the lakes without the expense of building 
dams may have more than a local application. 

On the eastern slope of the Sierra, near the town of Independence, a 
high mountain lake of this sort has been tapped by a cut about 10 feet 
in depth, which has given a flow, as reported, of several hundred inches 
more than customarily came from it before. 


Throughout the text of this work the author has endeavored to make 
due acknowledgment for information furnished and courtesies extended, 
in connection with each of the subjects treated. If any omissions have 
been made, their subsequent discovery will cause him sincere regret and 
mortification. To cover any such omissions in the first edition he begs 
to make a broad and general expression of gratitude for all aid extended 
in making the work more complete. 

Special acknowledgments are due the Director of the TJ. S. Geological 
Survey, and to Mr. F. H. Newell, Chief Hydrographer, for the use of the 
greater portion of the cuts and illustrations which embellish the fore- 
going pages, and are indispensable to the proper understanding of the text. 





U. S. Reservoir Surveyb in California. 








O I 



Clear Lake 

Independence Lake 
Webber Lake 

Donner Lake 

Soda Springs 

Truckee River 

Little Yoseiuite Valley 
Lake Tenava 

Tuolumne Meadows. 

Lake Eleanor 

Kennedy's Meadows. 

12 i Kennedy's Lake 

18 I Blood's Creek. 

Red Lake 

Pleasant Valley 

East Carson Creek 

Indian Pool, Deer Creek. 

Heenan Lake 

Silver King Valley 

Wolf Creek 

Dumont's Meadows 

Mokelumne River 


Pacific Valley 

Bell'sMeadows, CanyonCr 
Coffin's Hollow. •• •• 

Hull's Meadows 

Granite Lake 

Cherry Valley 

Lake Vernon 

Big Meadows 

Errarar*s Meadows 

HetcU-Hetchy Valley, . . . 
Little Truckee River . . . . 

Stampede Valley 

Twin Vallcv 

Little Truckne River. . . . 

Monument Peak 

Young's Crossing 

Grass Lake 

Hope Valley 

Harvey's Meadows 

American River 

Twin Lakes 











Sq. Mi. 












< < 




















































885,800, 50,921 







1,081-' 43,185 

.- » 






,45.770 1,910 
7,408t 860 
2,000 440 

U. S. Reservoir Surveys in 

1 f 

Truckee River, lower. . . . 
** " upper.... 

17 I Long Valley Creek 

18 West Carson River i 7,050 








































L 65 






\ 60 

'i 100 




















Iwin Lakes, ArkBDMB it. 


9 104 






Seven-Mile Cre«k 

















Weal Beaver Creek 

Sand Creek 

Eigbt-Hile Creek 

Arkansas, 8 m.«b. Pueblo 

St. Charles River 


4 250 








Santa Clara Hiver. 

ApisLapa River 

I'urg«lnire River 

Stonewall Vftllej 

Smith CanynnCrefk.... 



















Cottonwood Creek 

Two Butte Creek 

Nat. Basin, n. Rocky Ford 

■' " - La Junta.. 

" " " Arlington.. 

Pine Creek, n. 'Aiiivi^'. 

Timpas Cr^ek 

Las Animas Blver 








45 00( 





































7 10( 








169, (KK 











37 3IH 








10, 1» 













33 7M 



25 OK 




















11 M( 




O.WM) 900 

18.6401 1,530 
















22 & 

Location . 

Sun River. 



«« " ,' North Fork. 

" ** .South Fork. 

Willow Creek 



San River. 

Benton Lake 

Near Martinsdale. 

Daisy Dean Creek. 

«< 41 44 

N. Fork, Masselshell R... 





Sixteen-Mile Creek 

S. Fork, Smith River. . . . 

44 44 «4 (< 

Confederate Gulch 

• • . * 

Mitchell Creek 

Big Hole River 

Black-tail Deer Creek. . . . 

Beaver Head River 

Red Rock River 

Ruby River 

Nat. Basin, Choteau Co... 





Box Elder Creek 

West Otter Creek 

Sage Creek 

Judith River 

Dry Basin near Utica... 





Lebo Lake 

Near Martinsdale. 

• • . 
































. 80 











































































n. S. Reservoib Subyets in Utah. 

1 Bear Lake, partly in Idaho 

2 Silver Lake 

8 Twin Lakes 

4 Mary's Lake 

5 Sevier River, near Oasis.. 

6 Sanpitch River 

7 Sevier River 









































East Fork, Sevier Rirer. . 

Otter Creek 

East Fork, Sevier River. . 





Panquitch Lake, 
Blue Spring.... 



























































U. S. Reservoir Surveys ik New Mexico. 

Horse Lake 

Bowlder Lake 

Stinking Lake 

Vallecitos Creek 


VallecitoB Creek 


Rio Hondo 

Rio Colorado 


Rio Picuris and Rio Lusio 
Hio Grande . . . .• ........ 

Rio Jemex, East Fork. . . . 


Rio Salado 

Rio Jenies. 

Santa F6 Creek 

Rio Medio and Rio Fri jole 
Rio Mora 

Manuelitos Creek 

Cherry Valley Lake 

Rio Gallinas. 

Rio Pecos 

Rio Grande 

Rio San Jos^ 

San Mateo Creek 

Blue Water Creek 




Agna Fria Creek. 








. . . a . 

Rio Colorado. 
Rio Salado. . . 
Rio Alamosa. 
Rio Grande. . 






































UnBg. ? 




























































































( 21 



\ 86 
( 24 
















1 IJackson Lake. 



U. S. Reservoir Surveys is Wtoking. 
I I 840 1 1 500.0001 1 25 1 

n. S. Reservoir Surveys in Idaho. 
1 |8wan Valley, Snake Riveri | 5.865 | |1.500.000i | 125 ' 



Cost of Rbseryoik Construction per Acre-foot. American Rbseryoirs. 


Character of Dam. 

Capacity of 




Sweetwater dam, California 

Bear Valley dam, '* 

Hemet dam, <' ...... 

Escondido dam, " 

Lower Otaj dam, " 





Rock-fill,8teel core 



Rock.fiU crib 



Rock-fill and earth 








































111. 72 




La Mesa dam, <' 

Guyamaca dam, ** 

Buena Vista Lake, " 

Yosemite Lake, " 





English dam, " 

Bowman dam, " 

San l..eandro dam, ** 

Eureka Lake dam, " 

Fancherie dam, " ....... 

Lake Avalon, Pecos River, N. M.. 
Lake McMillan " ** « .. 
Tyler. Texas 






























Cache la Poudre, Colorado 

Larimer and Weld, " 

Windsor, " 

Monument, ** 

Apishapa, '< 

Hardscrabble, " 

Boss Lake, <* 

Saguache, " 

Seligman, Arizona 
















169 50 

Ash Fork, " 


Masonry and earth 

<4 <( i( 
(< l< << 


Masonry and earth 

MiiAnnrv 1 

416 30 

Williamfl, " 

Walnut Canyon, Arizona 

114 60 

New Croton, New York 


Titicus, " 


Sodom, " 


Bofl^Brook, " 


Indian River, ** 


Wiirwam, Conn 




Ebtimatbd Cost of Rsbsryoir Conbtbuction per Acrb-foot. Projectad 

American Reservoirs. 


ToDto Basin, Arizona 

SanCarloe, *' 

Riverside, " 

Buttes, *' 

Horseshoe, ** 

Bear Canyon, " 

Victor, California 

Manache Meadows, California . . 

Bock Creek, Nevada 

Columbus, Oliio 

Elephant Buttes, New Mexico. . . . 
Pecos River, •* . . . . 

8aud Lake, Texas 

Laramie, Wyoming 

Sweetwater River, " 

CloudPeak, *' 

Piney, " 

LakeDeSmet, ** 

liOTeland, Colorado 

Tarryall. •' 

Lost Canyon *' 

Character of Dam. 



Rock-fill & mas'ry 11 






Natural basin 
<< <« 

Rock-fill and earth 

Natural basin 
<* ** 

Natural rock-fill 

Capacity of 

























Cost per 

A era- foot of 

















81 ,049 











Cost of Reseryoir CoNSTRrcTiON per AcRE-yoor. Foreign Reservoirs. 


Couzon, France 

Furens, " 

Temay, " 

Ban, " 

Pas du Riot, *' 

C^artrain. " 

Lak*) Oredon, *' 

Houcbe, ' ' 

Liez. " 

Wassy. " 

Patas, India 

Ekruk. «• 

Ashti, " 

Lake Fife, *• 

Bhatgur, •' 

Tansa, *' 

Betwa. " 

Chnmbrumbaukum, India 

Villar. Spain 

Oilleppe, Belg^ium 

Remscheid. Germany. . • . 

Yyrnwy, Wales 

Beetaloo, Australia 

Character of Dam. 









Earth and masoniy 










Capacity of 




























Cost per 

A ere- foot of 






127. 0() 







49 00 














EscoNDiDO Ibbigation District Rebebyoib, California. 

[Area of tributary waterthed, 8 square mflee; elevation of base of dam above aea^level. 1800 feet.] 


above Base 

of Dam. 


Surface Area. 

CafMtcity of 














Capacity of reseTvoir as com- 
. pleted in 1895, 3,500 acre-feet. 
Outlet of reservoir is 16 feet 
above base. 


285* * 

Lower Otat Reservoir, California. 

[Area of tributary watershed. 100 square miles; elevation of base of dam above sea-level, S45 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 

































Outlet tuDoel 48 feet above base 
^ of dam. For cross-section of 
dam site see Fig. 177, p. 878. 

MoRBNA Reservoir, San Diego County, California. 

[Area of tributary watershed, 185 square miles; elevation of base of dam above sea-level, 8100 feet.] 


above Base 

of Dam. 

Surface Area. 

Capacity of 


















Outlet tunnel is at 80-foot con- 




tour. Rock-fill dam, with 




- aspbalt concrete facing. For 




cross-section of dam-site see 




Fig. 177, p. 378. 













La Mbba Rbseryoib, San Dibgo Coumtt, Califobnia. 

[Area of tifbutary watershed, 6 square milee; elevation of base of dam above sea-level, 48S.6 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 





































Uydraulic-fiU dam, completed 
- 1895, to 66-foot contour. Out- 
let at base of dam. 


Pine Valley Reservoir, San Diego County, California. 

[Area of watershed, 46 f^quare miles; elevation of base of dam, 8700 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 
































Dam proposed to be constructed 
\}j hydraulic process as a 

"] 1 earth-dam. For cross* 
section of dam site, see Fig. 
177, p. 878. 



Lake Hbmbt Rbsbryoib, Riyersidb County, Caufornia. 

[Area of watershed, 05 to 100 square miles; elevation of base of dam, 4200 feet.] 


above Base 

of Dam. 

Surface Area. 


Capacity of 











Lowest outlet at 45 feet. 





















. 252.0 








Top of dam as completed 1895. 










Little Bear Valley Reseryoir (Arrowhead Resbryoir Company), San 

Bernardino County, California. 

[Area of tributary watershed, 6.6 square miles; elevatioD of base of dam, 4M6.8 feet.] 



Surface Area. 

Capacity of 




























Bottom of outlet tunnel is 15.6 




feet above bed of creek at 



. 15.170 

^ base of dam; lowest founda- 




tions about 15 feet lower. 























Sweetwater Dah, San Diboo County, California. 

[Area of tributary watenhed, 186 square miles; eleyatlon of lowest outlet above sea^level. 140 feet.] 

above Low- 
est Outlet. 

Surface Area. 

Capacity of 





.Lowest outlet is 24 feet above 
> lowest foundations of dam. 










Grabs Valley Reservoir- bite (Arrowhead Reberyoir Company) 8an 

Bernardino County, California. 

[Area of tributary watersbed, 2.7 squire miles; elevation of base of dam-site. 5108.3 feet.] 


above Base 

of Dam. 

Surface Area. 

Capacity of 


above Base 

of Dam. 

Surface Area. 

Capacity of 

















































Huston Flat Reberyoir (Arrowhead Reservoir Company), San 

Bernardino County, California. 

[Elevation of creek-bed at dam-site, 4450 feet.] 


above Base 

of Dam. 

Surface Area. 

Capacity of 

above Base 

Surface Area. 

Capacity of 



A cm-feet. 



Acre- feet. 
















































Pauba Rbbbbyoir-sitb, San Diego Cottktt, Calxfobitia. 

[Area of tributary watershed, 372 square miles; elevation of base of dam, 1850 feet.] 


above Base 

of Dam. 

Surftuse Area. 

Capacity of 























Mazimam depth to bed rock 
V aboat 26 feet in center of 














Warneb's Ranch RsBBByoiB-fflTE. San Luib Ret Riybb, San Diego County, 


[Area of tributary watershed, 210 square miles; elevation of base of dam, S61S feet. Vor crtMS^ectioo 

of dam-site see Ak- 177, p. 878.] 

Height above 

Surface Area. 

Capacity of 




































Santa Maria Valley Resbrtoir-bitb, Sak Diego County, California. 

[Area of tributary watershed, 60 square miles; eleyation of base of dam, 1800 feet. For cross-sectioo 

of dam-site see Fig. 177, p. 878.] 

Height above 
Base of Dam. 

Surface Area. 

Capacity of 





















4 500 




Pamo Valley Rsseryoir-site. San Diego County, California. 

[Area of tributary watershed, 125 square miles; elevation of base of dam, 808 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 

































Outlet of reservoir to be at tLe 
40-foot level. For cross-section 
of dam-site, see Fig. 177, p. 878. 




Dye Valley Reservoir-site, San Diego County, California. 

[Area of tributary watershed, 6 square miles; elevation of base of dam, 2200 feet.] 

Height above 
Base of Dam. 



Capacity of 




To be fed by diversion of Santa Ysabel 
Creek, draining 80 square miles of 
mountain territory. 



CuTAMACA Rrservoik. San Diego County, Califori^ia. 

[Area of tributary watershed. 11.08 square miles; elevation of dam, about 48S0 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 



















Top of dam, 41 . 6 feet above base. 
^ Floor of wastewaj at 85-foot 
contour above base. 


Barrett Rbssrvoir-site, San Diego County, California. 

[Area of tributary watershed, 250 square miles; elevation of base of dam, 1600 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 

Acre feet. 





















8 975 








Used as a diverting-dam, to the 

height of 60 feet, for diverting 

1 Morena reservoir water to the 

' Lower Otay reservoir. For 

cross-section of dam>site, see 

Fig. 177, p. 878. 



Upper Otat Rbsbryoir-sii'b. San Dieoo County, California. 

[Area of tributary watershed, 8 square miles; elevation of base of dam, 480 feet. For cross-section of 

dam-site see Fig. 177, p. 873. J 

Height above 
Base of Dam. 

Surface Area. 

Capacity of 
















Bear Yallet Rebbryoir, San Bernardino County, California. 

[Arf a of tributary watershed, 56 square miles; elevation of base of dam, about 6200 feet.] 


above Base 

of Dam. 

Surface Area. 

Capacity of 


above Base 

of Dam. 

Surface Area. 

Caps city of 





















































South Antelope Valley Irrigation Company's Alpine Rbbbrtoir, Los 

Angeles County, California. 

[Area of tributary watei^ihed, 6 square miles; elevation bottom of reservoir, 2779 feet.] 


above Base 

of Dam. 



Surface Area. 

Capacity of 





/ 2,734 

Filled by 8 miles of conduit from 
K Little Rock Creelc, with drain- 
age of 61 square miles. 



Victor Reservoir- site, Sak Bernardino County, California. 

[Area of tributary watershed, ISOO square miles; elevation of base of dam, 270S feet.] 

Height above 
Base of Dam. 


Surface Area. 

Capacity of 





San Leandro Reservoir, Lake Chabot, Oakland Waterworks, California. 

[Area of tributary reservoir, 60 square miles; elevation of base of dam above sea-level, 115 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 


















Outlet level. 



Higli- water mark at present, 
120 feet above base; capac- 
ity, 18, 1 1 5 acre-feet, or 5,825,- 
845,000 gallons. 

Man ACHE Meadows Reservoir-site. South Fork Kern River. California. 

[Area of watershed, 155 square miles; elevntion of dam-site, 8200 feet.] 

Height above 
Base of Dam. 

Surface Area. 

Capacity of 

































Big Meadows Rbbbbyoib-sitb. Salmon Fork Kern Riybr, California. 

[Area of watershed (estimated), SS5 square miles.] 

Height above 
Base of Dara. 

Surface Area. 

Capacity of 




























North Fork Lake Reservoir- bite, Upper Kern Riyer. California. 

[Elevation, 6500 feet.] 


above Base 

of Dam. 


Surface Area. 

Capacity of 










Outlet level. 



BuENA Vista Lake Reservoir, Lower Eern River, California. 

[Elevation above sea-level, 860 feet.] 





Surface Area. 

Capacity of 







\ A depth of 6 feet below the bot- 
y torn of outlet-canal is never 
) drawn upon. 



FoNTO Basin Reservoir- bite, Salt Riveb, Abizoka. 

[Area of watershed, 6*^60 square miles; elevation of base of dam, 1935 feet.] 



above Dam 
at Low- 

Area Flooded. 

Capacity of 

above Dam 
at Low- 

Area Flooded. 

Capacity of 

water Mark. 

water Mark. 
















































































































Queen Creek Reservoir-site, Arizona. 

[Area of watershed, 80 to 850 square miles; elevation of base of dam, creek bed, 2050 feet.] 


above Base 

of Dam. 

Surface Area. 

Capfu;ity of 

























Height of dam suggested, 115 




V feet, would flow to the height 




of 110 feet. 



















Bttttes Reservoir-bite, Gila River, Arizona. 

[Area of tributary watershed, 18,750 square miles; elevation of base of dam (low water), 1800 feet.] 


above Base 
of Dam. 

Surface Area. 

Capacity of 
































Height of dam proposed, 170 
feet, will carry 160 feet depth 
of water. 



























AgxitL Fria : 

dam, 206-217 

reservoir, 206 

river, 206 
Algiers, dams, 122 
Alicante, Spain : 

dam, 252 

reservoir, 252 
Allen, Cbas. P.. 67 
Almanza dam, Spain, 252 
Alpine reservoir, 299, 803, 899 
American River, 179 
Anderson, Col. Latham, 116 
ApisLapa state dam, Colo. ,'297 
Apportionment of water, Hemet district, 

Aqnedact Commission, N. Y., 287, 288 
Arch dam, 119 
Area : 

Hemet irrigation, 168 

Pecos Valley, 862, 868 
Areas : 

reservoir, 392-403 

watershed, 392-403 
Arizona reservoir surveys, 320 
Arrowhead Reservoir Company, 868 
Ash Fork, Arizona : 

reservoir, 214 

steel dam, 214, 222-224) 
Ashti dam, settlement of, 279 
Ashti tank, India, 277-279 
Asphalt concrete, 86. 208 
Asphalt, use of. for protection of steel core 

of Otay dam, 21 
Assiout dam, Upper Egypt, 278 
Assuan dam, Egypt, 272 
Anstin, Tex.: 

dam. 242-247 

failure of, 246 

reservoir, 245 

Aymard, M., 258 

Babcock,E. S., 20 

Bainbridge, F. H., 222 

Balanced valves, 81, 67, 68 

Ban dam, France, 256, 891 

Barrett dam, California, 82-85, 898 

Barton, E. H., 179 

Basin Creek, Mont., dam, 280-285 

Bear Canyon dam, Arizona, 850, 891 

Bear Valley dam, California, 120, 125, 163- 

174, 899 
Bear Valley Irrigation Co., 168 
Beetaloo dam, S. Aus., 122, 271, 891 
Betwa dam, India, 269, 891 
Bhatgur dam, India, 267, 891 
Bidaut. M., 260, 261 

Big Meadows reservoir-site, Cal., 888, 401 
Blake, Prof. W. P., 59, 68 
Blasting, types of heavy blasts : 

Lower Otay dam, 27, 29 

Morena dam, 89 
Blauvelt, Louis D.. 49 
Bog Brook reservoir. New York, 288 
Bofler, Alfred P., 45 
Bombay, India, water-supply. 266 
Bonds, La Grange dam, 178 
Boss Lake state dam, Colo., 297, 298 
Bostaph, W. M.. 66 
Bousey dam, France, 258, 259 

failure of 258 
Bonvier, M., 256 
Bowie, A. J.. 73 
Bowman rock-fill dam, California, 74, 75 

reservoir, 74 
Boyd's Comer, New York : 

dam, 289 

reservoir, 239 
Brick and asphalt facing of Remscbeid 
dam, Germany, 261 




Bridgeport, Conn.: 
dam, 241 
reservoir, 241 
Brodie, Maj. Alex. O., 68 
Brown, F. B , 164 
Buena Vista Lake, California : 
dam, 293 
reservoir, 298, 401 
Bums, K. B., 228 

Cablewaj, 180 

Lidgerwood, 22, 89, 285 
Cache la Poudre, Colo.: 

dam, 295, 296 

reservoir, 295, 296 
Cagliari dam, Italy, 262 
Caimanche, Texas, reservoir-site, 862 
Cambie, H. J., 105 
Campbell^ J. L., 861 
Canadian Pacific Ry., Ljdraalic fills on, 

100, 101, 105, 106, 107, 109 
CaDal : 

Modesto, 178 

Poona reservoir, 267 

Siphoning, across Rio Grande River, 

Turlock, 178 
Canal lines. Rock Creek, 868, 864, 866 
Capacity of reservoirs, 75, 892-403 
Castlewood, Colo.: 

canals, 45 

dam, 4&-47 

reservoirs, 45 
Catchment : 

Escondido reservoir, 18 

Otay Creek, 27 
Cauverypank tank, 277 
Cedar logs, use of, Walnnt Grove dam, 

Cement, 21, 81 

mixing, Hemet dam, 154 
Center core. Lake Christine dam, 100 
Ceylon tank, 274 
Chabot, A., 77 

rhartrain dam, France, 258, 891 
Chatsworth Park dam. California, 42-44 
Chazilly dam, France, 255 
Chittenden, Capt. H. M., 71, 810. 820 
Chnmbrnmbankam tank, 277, 891 
Clerke, W. T. C, 267 
Cloud, H. H., 49 
Cloud Peak, reservoir-site, Wyo., 816, 891 

Coleman, J. S., 237 
Colorado state dams, 296 
Columbia Colonization Co., Cal., 374 
Concrete, 81, 66. 67, 117. 271 

Ash Fork dam, 223 

base Alpine reservoir gates, 804 

collars, 147 

dam. 189, 229-288, 271 

La Mesa dam, 90 

mixer, 147 

mixing, San Mateo dam, 192, 198 

San Mateo dam, 189 
Conduit : 

Escondido reservoir, 5 

La Mesa dam, 90 

Sweetwater dam, 152 
Congressional River and Harbor Act, 71 
Construction plant. Hemet dam, 161 
Convict labor, Folsom dam, 179 
Contents Basin Creek dam, Mont., 235 
Cornell University dam, 240 
Cost of : 

Ash Fork dam. 224 

Assuan dam, 273 

Austin dam, 245, 251 

Bear Canyon reservoir, 851, 891 

Bear Valley dam, 165 

Bowman dam, 74 

cement. Bear Valley dam, 164 

conduit Sweetwater dam, 152 

Denver Water Co's. dam, 71 

English dam, 78 

Escondido dam, 14, 15 

hydraulic filling Canadian Pacific Ry., 
105, 106 

hydraulic filling Northern Pacific Ry., 

Indian River dam, 240 

La Grange dam, 176 

Lake Christine dam, 100 

Lake McMillan dam, 53 

materials, Hemet dam, 154 

New Croton dam, 237 

Norway, Mich., dam, 236 

Pacoima dam, 206 

Padaviltank, 275 

Periyar dam, 271 

reservoir construction, 390, 891 

Rio Grande reservoirs, proposed, 869 

Rio Verde reservoirs. 848, 850 

San Leandro dam, 77 

Segilman dam, 220 



Coitof : 

Sodom dam, 288 

Sweetwater dam, 187, 895 

Titicus dam, 287 

Tyler dam, 84 

Victor reservoir and canals, 880, 891 

Vyrnwj dam, 262, 268 

Walnut Canjon dam, 226 

Williams dam, 231 
Cotatay dam, France, 257 
Coventry, W. B., 118 
Cracking of dams, 122, 148 
Cross-section, Agua Fria dam and reservoir, 

Cross-sections, dam-sites, San Diego Co., 

Crowe, H. S., 179 
Crugnola, Q., 264 

Crystal Springs reservoir, California, 208 
Curved dams, 118, 120, 121, 122 
Cushion, water, 120 
Cuyamaca dam, 281, 898 

Dam : 

cracking of, 122, 148 

curved. 119-122 

earthen, 267 

hydraulic-fill, 76 

masonry, 117 

necessary width of, 119 

rock-fill, 1 
Dam-sites, see Reservoir-sites. 
Davis, Arthpr P., 821 
Davis, Chester 6., 280 
Davis and Weber Counties Canal Company, 

Deacon, Geo. F., 268 
Delocre, M., 118, 121, 256 
Denver Water Company's dam, 66-70 

reservoir. 71 
Derricks, 89, 181 

use of, at Walnut Grove dam, 60 

water power, 161 
Design and construction of dams, 252 
Design, conditions of Bhatgur dam, 268 
Details of Sweetwater dam, 146 
Dimensions : 

Barrett dam, 82 

Bear Valley dam. 164 

Bridgeport dam, 289 

La Grange dam, 176 

Seligman dam, 220 

Distributing system Escondido reservoir, 14 
Distributing system Sweetwater reservoir, 

Diverting dam, 206-217 

Fort Selden, N. M., 854, 857 
Djldionla dam, Algiers, 265 
Drainage area : 

Colorado River, 245 

English dam, 71 

Indian River reservoir, 240 
Duchesnay, Edmund, 105 
Dulsura conduit, 82 
Dulzura Pass, 27 
Duty of water, Pecos Valley, 58 

Earthen dams : 

Apishapa stat«, Colo., 297 
Boss Lake state, Colo., 297, 298 
Buena Vista Lake, Cal., 298, 401 
Cache la Poudre, Colo., 295 
Cuyamaca, Cal., 281-289 
experiments on materials for, 116 
Hardscrabble state, Colo., 297 
history of, 274-279 
India, 274-280 

Merced reservoir, California, 289 
modes of construction, 280 
Monument Creek, Colo., 296 
Pilarcitos, California. 294, 295 
Saguache state, Colo. , 298 
San Andres, California, 294. 295 

E^rth, packing of, in earthen dams, 281 

Earthquake crack. Southern California, 299 

East Canyon Creek dam, Utah, 64, 65 

Eastward, J. S., 99 

Einsiedel dam, Germany, 262 

Ekruk tank, 277 

El Cajon Valley, 125 

Elche dam, Spain, 252 

Elephant Bntte, New Mexico : 
dam, 852 
reservoir, 854-856 

El Molino dam, California, 125 

El Paso, Texas, international dam, 851 

Embankments, Madras. 275 

English dam, Cal., 71-74 
failure of. 78 

flood-wave from bursting of, 78 
reservoir, 71 

Escondido dam, California, 2-19, 892 
distributing system, 14 

Escondido, irrigation district map, 2 



Evaporation, 174 

Assuan reservoir, 378 

Baena Vista Lake reservoir, d04 

Cuyamaca, 285 

Rio Grande River, 862 

Sweetwater reservoir, 152 ^ 

Tansa dam, 26G 
Explosion of heavy blasts, £x>wer Otay 
rock-fill dam, 29 

Fiulure of dams : 

Austin dam, 246, 261 

Boasey dam, 258 

Habra dam, 263 

Lynx Creek dam, 228 

Puentes dam, 253 
Fanning J. T., 242 
Farren, George, 121 
Feeder canal : 

Escondido irrigation district, 8 

Little Rock Creek, 800 
Feeder conduit, Escondido irrigation dis- 
trict, 6 
Fishway, Twin Lakes reservoir, Colo., 807 
Floods of the Nile, 278 
Flood-wave from bursting of a California 

dam, 78 
Folsom dam, 179-189 
Forclilieimer, Prof., 121 
Fortier, Prof. 8., 66, 116 
Frizell, Jos. P.. 242 
Fteley, A., 286. 288 
Fuertes, Prof. E. A., 241 
Furens dam, 118, 891 

Gates : 

concrete base for, 804 

Escondido dam, 11, 18 

quick-opening, Lake Avalcm re6ervoir, 

railroad, 279 

stems, 99 

valve, 90. 181 
Geelong dam, Ans., 271 
Giants' tank, Ceylon, 275 
Gila River, Arizona, proposed reservoirs 

on, 889 
Gileppe dam, Belgium, 260, 891 
Glacial Flour, 809 

Gophers, guarding reservoir against, 168 
Gorzente dam, Italy, 262 
Gowen, Chas. F., 287 

Qraeff, M., 266 

Gran Cheurfas dam, Algiers, 266 

Grands-Cheurfas dam, 122 

Gravel, natural storage-reservoirs in, 811 

Gravity dam, 116 

Greenalch, W., 240 

Gros-Bois dam, France, 264 

Gransky, C. E., 280 

Guadalantin River, 258 

Habra dam, Algiers, 122, 268-265 

failure of, 264 
Hamiz dam, Algiers, 122, 265 
Hardscrabble state dam, 297 
Hassayampa River, 58 
Headgates Lake Avalon, N. M., dam, 60 
Hemet dam, California, 152-163 

construction plant, 161 

reservoir, 159 
Herschel, Clemens. 116 
Hi jar dam, Spain, 254 
Hill, A., 268 
Hilton cement, 235 
Holyoke dam, 116 
Homogeneity, masonry dams, 117 
Hooker, Elon H., 241 
Horse-power, use of, for derricks, 181 
Horseshoe reservoir-site, 848, 891 
Howells. J. M., 78, 84, 99 
Hudson Canal and Reservoir Company, 843 
Hyde, F. S., 285 
Hydraulic construction : 

Georgia, 116 

Seattle, Wash., 115 

Tacoma, Wash., 115 
Hydraulic cylinder, 68 
Hydraulic-fill dam construction, 76 
Hydraulic- fill dams : 

Holyoke, Mass., 116 

Lake Christine, 98-100 

La Mesa, 84-98 

San Leandro, 77, 78 

Temescal, 77, 78 

Tyler, Texas, 78-84 
Hydraulic filling, Canadian Pacific Ry.» 

100, 101, 105, 106, 107. 109 
Hydraulic filling Northern Pacific Ry., 

106, 111, 114 
Hydraulic jack for raising shatter, Fol- 
som dam, 189 
Hydraulic mining districts. Northern Cal., 










ImpoaDding reservoirs, 121 

Improved cement, 241 

Independence, Cal., higli mountain lake 

tapped, 884 
Indian River, New York : 

dam, 289 

reservoir. 240 
Inlet valves, 181 
Inlet tower, 181 

Interlocking masonry dams, 117 
Intze, Prof., 121. 262 
Investigation, reservoir-sites, 321 
Irrigated lands, Hemet, 153 
Irrigation area, Sweetwater, 149 

Johnstown, Penn., 73, 281 

Kelly, Wm., 236 
Kern Lake reservoir-site, 888 
Kern-Rand Reservoir and Electric Com- 
pany, 882 
Kern River, Cal., reservoir-sites, 880 
Kingman, Ariz., submerged dam, 214, 

Krantz, J. B., 121, 256 
Krantz, M., 256 

La Orange dam, Cal., 174-179 

Lake Avalon, N. M., dam, 47-52 

Lake Christine, California, hydraulic-fill 

dam, 98 
Lake De Smet, Wyo., reservoir-site, 810, 

Lake Hemet, 158, 894 
I^ake McMillan : 

dam, 51, 58 

reservoir, 58 
Lakes, Sierra Nevada Mis., 888 
La Mesa, Cal.: 

dam, 20, 84, 95, 98, 898 

reservoir, 91, 97 
Land, Gordon, 296 
Larimer and Weld reservoir, 809 
Larimie reservoir-site, 810, 891 
Leakage : 

Escondido dam, 11 

Sweetwater dam, 148 

Walnut Canyon dam, 227 

Walnut Creek dam, 60 
Linda Vista irrigation district, 878 
Lippincott, J. B., 174, 802, 821. 889 
Little Bear Valley reservoir, 871, 894 

Little Bear Valley reservoir-site, 867 
Little Rock Creek irrigation district, 878 
Loss of life : 

Bousey dam failure, 258 

Habra dam failure, 268 

Johnstown dam failure, 281 

Puentes dam failure. 253 

Walnut Grove dam failure, 60 
Loss of water, Assuan reservoir, 278 
Lost Canyon, Colo. : 

natural dam, 868, 391 

reservoir-site, 866 
Lower Otay, rock-fill steel-oore dam, 19- 

Lozoya dam, Spain, 254 
Ludlow gates, 226 
Ludlow valves, 66 
Lux M. Haggin, 298 
Lynx Creek dam, Ariz., 228, 229 

failure, 228 

Mac Kenzie, A. T., 270 

Man, A. P., 841 

Manache Meadows dam and reservoir, 880, 

881. 891, 400 
Marston Lake, Colo., 810 
Masonry dams : 

Agua Fria, Ariz., 206-217 

Alicante, Spain, 252 

Almanza, Spain, 252 

Assiout, Upper Egypt, 278 

Assuan, Egypt, 272 

Austin. Texas, 242-251 

Ban, France, 256, 891 

Basin Creek, Mont., 280-285 

Bear Valley, California, 163-174, 899 

Beetaloo, S. Aus., 271, 891 

Betwa, India, 269 

Bbatgur, India. 267, 891 

Bousey, France, 258 

Boyd's Corner, New York, 289 

Bridgeport, Conn., 241 

Cagllari. Italy, 262 

Cbartrain, France, 258 

Chazilly. France, 255 

Cotatay. France. Wt 

Cornell University, New York, 240 

Djidionia, Algiers, 265 

Einsiedel. Germany, 262 

Elche, Spain, 258 

essential features of, 258 

Folsom, California, 179, 189 



Masonry dams : 

Furens, France, 255, 891 

Geelong, Australia, 271 

general principles of, 118, 119 

Gilleppe, Belgium, 260 

Oorzente, Itelj, 262 

Gran Cheurfas, Algiers, 265 

Grosfiois, France, 254 

Habra, Algiers, 263 

Hamiz, Algiers, 265 

Hemet, California, 152-168 

Hijar, Spain, 254 

Indian River, New York, 239 

Kingman, Arizona, 214, 217 

La Grange, California, 174-178 

Lozoja, Spain, 254 

Lynx Creek, Ariz., 228, 229 

Mexican, 251 

Mouche, France, 260, 891 

New Croton, N. Y., 286 

Nijar. Spain, 254 

Norway, Micli., 235, 286 

Old Mission, California, 125 

Pacoima, Cal., submerged dam, 205-211 

Pas Du Riot, France, 257, 891 

Periyar. India, 269 

Pont, France, 257 

Poona or Lake Fife, India, 267, 891 

Portland, Oregon, 229-288 

Puentes, Spain, 258 

Remscbeid, Germany, 261, 891 

San Mateo, California, 189-205 

Seligman. Arizona, 214, 219-221 

Sodom, New York. 288, 239 

Sweetwater. California, 20, 120, 122, 
125. 126-152. 895 

Tansa, India. 266 

Ternay, France, 256, 891 

Titicus. New York, 287 

Tlelat, Algiers. 265 

Tytam. China, 272 

Val de Infierno, Spain, 258 

Verdon, France, 257 

ViUar. Spain, 254, 891 

Vingeanne. France, 256 

Vyrnwy, Wales, 262, 891 

Walnut Canyon. Arizona, 214, 225-228 

Wicrwam, Conn.. 241 

Williams. Arizona, 214, 224 

Zola. France, 255 
Matbematics, of curved dams, 121 
Maxwell. J. P., 297 

McDowell reservoir-site, 848, 849 

McHenry, E. H., Ill 

McReynolds, O. O., 307, 808 

Measuring-box, 212 

Merced reservoir-dam, 289 

Mexican dams, 251 

Mills, Major A., 851, 861 

Mining reservoirs Northern- California, 

capacities of, 75 
* 'Modern Mexico," acknowledgments to, 

Modesto irrigation district, Cal., 176, 179 
Moles worth, Guilford L., 118 
MoncrieflE, J. C. B., 271 
Montgolfier, M., 256 
Monument Creek dam, Colo., 296 
Morena dam, California, 19, 85-41, 892 
outlet, 89 
reservoir, 40 
Mormon Canyon, Cal., 42 
Mouche dam, 122, 260, 391 
Mountain pine for conduits, 162 
Movable shutter, for increasing height of 

water at low stage, Folsom dam, 

Cal., 189 
Mudduk Masur, 277 

Natural dam. Lost Canyon, 868-866 

Natural reservoirs : 
Alpine. Cal., 209 

Gravel-bed storage- reservoirs, 811 
Lake De Smet reservoir-site, Wyo., 

Laramie reservoir-site, Wyo., 810 
Larimer and Weld. Colo.. 809 
Loveland reservoir-site, Colo., 810 
Marston Lake, Colo., 810 
Twin Lakes, Colo., 808 

Nettleton, £. S., 49 

Ne<v Croton dam, N. Y., 236 

Newell curve showing relation of run*- off 
to rainfall. 204, 205, 285 

Newell, F. H., 208 

Nicholson, W. D., 228 

Nijar dam, Spain, 254 

Nira canal, India, 268 

Northern Pacific Ry., 111-114 

Norway, Mich., dam, 285, 286 

Nueces reservoir-site, Texas, 862 

Old Mission dam, San Diego, Cal., 125 
Otay Creek, Cal., 19 





Outlet : 

Alpine reBervoir, 80d-807 

Ash Fork dam, 228 

Bear Valley dam, 166 

Denver Water Company's dam, 67 

East Canyon Creek dam, 66 

Hemetdam, 162 

Lake Christine dam, 100 

Lake McMillan dam, 63 

Merced reservoir dam, 289 

Monument Creek dam, 296 

Morena dam, 89 

San Mateo dam, 203 

Seligman dam, 221 

Twin Lakes reservoir, 808 

Walnut Canyon dam, 226 

Walnut Grove dam, 61 
Outlet-gate, La Mesa dam, 98 
Outlet pipes, 181 

building of, 281 
Outlet tunnel : 

Lower Otay dam, 81 

Morena dam, 89 

Pacoima Creek, 205 

submerged dam. 205-211 
Padavil : 

tank of, 274 

cost of embankment, 275 
Parabola, 221 

Parabolic curve, for top of dam, 223 
Paraffine paint, 61 
Pas Du Riot dam, France, 257, 891 
Pecos : 

canal, 47 

Irrigation and Improvement Company, 

River, 54 

Valley dam, 47. 891 

Valley, area of arable, irrigable land 
in. 862. 368 
Pelletreati, M., 121 
Pennycuick, Col., 271 
Percolation, rate of, 876 
Periyar dam, India, 269 
Pick-up vreir, 162 

head of distributing svstem Elscondido 
irrigation works, 14 
Pilarcitos dam, California, 295 
Piling for dam foundation, 856 
Piney, reservoir-site, Wyo., 816, 891 


Folsom dam, 179 

Pacoima dam, 211 

San Mateo dam, 195 

Sweetwater dam, 145 
Pont dam, France, 257 
Poona, or Lake Fife dam, India, 267 
Portland cement, 21, 117, 179, 205 
Portland, Oregon, concrete dams, 229, 283 

reservoirs, 229, 230, 288 
Power drop, Folsom canal, 179 
Precipitation : 

Bear Valley, 174 1^ ^ 

data on U. S. weather bureau, 57 

Puentes dam, 253 

Spring Valley, California, 208 

Salt River watershed. Ariz., 348 

Victor watershed, 876 
Pressure Puentes dam, 253 
Pressures, maxima, of dams, 119 

greatest recorded, of water on ma- 
sonry, 286 
Profiles : 

Bear Valley, Sweetwater, and Zola 
dams. 120 
Projected reservoirs, see Reservoir-sites. 
Puddle core. 281 

Puddle core hydraulic dams, 77, 100 
Puentes dam, Spain. 253 
Pumping plants, Sweetwater district, Cal- 
ifornia, 150, 151 

Quarries, 60 

Quarry, Lower Otay dam, 27 
Quick-opening gates. Lake Avalon reser- 
voir, 51 
Quicklime, Habra dam, 264 
Quinton, J. H., 389 

Rafter. Geo. W., 240 

Rainfall, Cuyamaca reservoir, 285 

Rain gauges, Little Bear Valley, 371 

Railroad gates, 296 

Rate of flow, underground waters, 802 

Redwood, facing Escondido dam. 7 

conduit, 162 
Remscheid dam, Germany, 121. 261, 891 
Reservoir : 

areas. 892. 403 

Ash F(.rk, 228-226 

Bear Valley. 166, 174. 175 

Bowman. 74 



Reservoir : 

Bridgeport, 241 

Capacities, 892, 408 

Construction, by general government, 

cost of construction, 800, 891 

Denver Water Company's, 71 

elevation of, 892, 408 

Habra dam, 268 

Hemet, capacity of, 162 

Indian River, 240 

La Mesa, 91, 97 

Lower Otay, 26-28, 892 

Morena, 40, 892 

Rock Creek, 868, 864, 891 

San Leandro, 78 

Seliguian, 221 

Sodom, 288 

South Antelope Irrigation Company, 

Sweetwater, 187, 895 

Wigwam, 242 

Williams, 224 
Reservoirs : 

Ceylon, 276 

natural, 299 

near San Diego, Cal. , 41 

Portland, Oregon, 280 

projected, see Reservoir-sites. 
Reservoir projects : 

California, 870 

San Diego County, 872 
Reservoir-sites : 

Bear Canyon, Ariz., 850, 891 

Big Meadows, Cal., 888, 401 

Caimancbe, Texas, 861 

Cloud Peak, Wyo., 816, 891 

data on, 886, 408 

Elephant Butte, Texas, 851, 891 

El Paso international, Texas, 851 

Horseshoe, Ariz., 844 

Kern Lake. Cal., 888 

Kern River, Cal., 880, 888 

Little Bear Valley, Cal., 867 
map, 175 

Lost Canyon, Colo., 868, 891 

Manache Meadows, Cal., 880, 891, 400 

McDowell, Ariz., 848 

Nueces River, Texas, 862 

Piney, Wyo., 816 

recommendations on, 821-328 

Rock Creek, Nev., 868, 891 

Reservoir-sites : 

San Carlos. Ariz., 380, 891 

San Diego County, Cal., 872 

Sand Lake, Texas, 802, 891 

selection by L^. S. Geolog. Survey, 
314, 821 

Swan Lake, Idaho, 814 

Sweetwater, Wyo., 815. 891 

Tonto Basin, Ariz., 339, 391, 402 

Upper Pecos, Texas, 362 

Victor, Cal., 878, 391, 402 
Reservoir surveys, U. S., 814, 821, 848-351 
Rio Grande Dam and Irrigation Company, 

Rio Grande River : 

evaporation from, 861 

proposed reservoirs, 851 

silt of, 861 

water-supply of, 860 
Rio Verde Canal Company, 844 
Rio Verde River, projected reservoirs on, 

Robinson, Col. E. N., 59-62 
Rock Creek reservoir-site, 863, 864 
Rock-fill dams : 

Barrett, Cal., 32-85 

Bowman, Cal., 74, 75 

Castle wood, Colo., 48-47 

Chatsworth Park, Cal., 42-44 

Denver Water Company's, Colo., 66-70 

East Canyon Creek, Utah, 64r-66 

English dam, Cal., 71-78 

Escondido, Cal., 2-19. 892 

Lake Avalon, N. M.. 47-53 

Lake McMillan, N. M.. 51, 53-59 

Lower Otay, Cal., 19-82, 892 

Morena, Cal., 85-42 

Pecos Valley, N. M., 47 

Upper Otay. Cal., 41-43, 399 

Walnut Grove, Ariz., 60-68 
Rubble-concrete, 117 
Run-off, 203. 204 : 

Bear Valley, Cal., district, 174 

Cuyamaca watershed, 285 

Rock Creek watershed. 868 

Salt River, Ariz., 844 

Sweetwater, Cal., district, 174 

Saguache state dam, Colo., 297 

Salt River, Ariz., 841-844 

San Andreas dam, Cal., 295 

San Carlos reservoir-site, Ariz., 880, 391 








8aD Diego River» Cal., 125 
San Diego County reservoir-sites, 872 
San Elijo Creek, Cal., 2 
San Joaquin £leciric Company, 98 
San Leaudro hydraulic- fill dam, 77, 400 
San Luis Rey River, Cal., 5 
San Mateo dam, Cal., 189-205 
Sand Lake reservoir-site, Texas, 862 
Santa Ana River, Cal., 164 
Santa Fe Ry., storage- reservoirs, 214 
Savage, U. N., Chief Engineer San Diego 
Land and Town Co., 81, 187, 188, 151 
Sazilly, M., 118 

Section, Walnut Canyon dam, Ariz., 227 
Sedimentation, Sweetwater reservoir, Cal., 

Self-balanced gates, 278 
Seligman dam, 214, 219-221 
Settlement, Ashti dam, 279 
Seymour, J. J., 99 
Sig-dam, 122 

deposit of, 151, 250 

Rio Grande River, 361 

volume of, carried by river Po, Indus, 
Ganges, Mississippi, and Colorado, 
Siphoning canal across the Rio Grande 

River, 859 
Sluicing-head, 76 

volume of water necessary for, 76 
Sodom, N. Y., dam, 288 
South Antelope Valley Irrigation Company, 

Cal., 299, 801 
South Fork reservoir, Penn., 78 
South Platte dam, Colo.. 70 
Southern California Mountain Water Com- 
pany, 19 
Spanish dams, 118 
Spillway : 

Bear Valley dam, 166 

Denver Water Company's dam, 67 

East Canyon Creek dam, 66 

Hemet dam, 158 

lack of, 281 

Lake Christine dam, 100 

Lower Otay dam, 22 

Seligman dam, 221 

Sweetwater dam, 188, 189 

Tyler dam, 88 

Walnut Creek dam, 62 
Spring Valley Water- works, 189 

State dams. Colo., 296 
Steel-core rock-fill dams : 

Denver Water Company's, 66 

East Canyon Creek, 64 

Lower Otay, 19 
Steel dam : 

Ash Fork, 214, 222-224 

cost of, 224 

questionable success of, 228 
Storage-reservoirs : 

natural gravel, 811 

Santa Fe Uy., 214 
Strains, masonry dams, 118 
Submerged dams : 

Pacoima, 205-211 

Kingman, 214-219 
Surveys, reservoir, U. S. Geolog. Survey ^ 

814. 821, 886-889 
Swan Lake reservoir-site, 814 
Sweetwater, California: 

dam, 20, 120, 122. 125, 126-152, 895 

reservoir distributing system, 153 
Sweetwater, Wyo., reservoir-site, 815 
Swift River, Mass., reservoir, 815 

Tables : 

cost of reservoir construction per acre- 
foot, American reservoirs, 890 
cost of reservoir construction per acre- 
foot, projected American reservoirs, 
cost of reservoir construction per acre- 
foot, foreign reservoirs , 891 
reservoir capacities and areas, 892- 

reservoir capacities, areas, \%atershed 
and elevation, from U. S. reservoir 
surveys, 886-889 
Tadini. M.. 250 
Tamarack logs, 78, 74 
Tanks : 

Ceylon. 274 
India, 277 
Tansa dam, India. 266 
Temescal hydraulic-fill dam, California, 77 
Tension in dams. 122 
Tension strains. 118 
Ternay dam, France. 256, 891 
Tests concrete and masonry Vymwy dam, 

Tia Juana River, California, 27 
Timber crib rock-fill dam, 74 



Titicus dam, 237 
Tlelat dam, Algiers, 265 
Tonto Basin , Arizona, dam- and reservoir- 
site, 339, 891 
Tower : 

reservoirs, 362 

Sweetwater dam, 132 
Tramways used, Escondido dam construc- 
tion, 8 
Triangular form of dam, 119 
Trass mortar used in Remselieid dam as 
a substitute for Portland cement, 261 
Tuolumne River, Cal., 174 
Turbine wheels, at Folsom dam, Cal., 189 
Turlock Irrigation district, 176, 179 
Twin Lakes reservoir, Colo., 303 
Tyler, Texas, liydraulic dam, 78, 79, 81, 85 
Tytam dam, China, 272 

Underground waters, rate of flow of, 218, 

Upper Otay, Cal. : 

dam, 41-43 

reservoir, 399 
Upper Pecos, reservoir-site, 862 
Utah Agricultural Experiment Station, 116 

Val de Infiemo dam, Spain, 253 
Vallejo dam, Cal., 280 
y eranum tank, India, 277 
Velocity of flow through sand, 218 
Verdon dam, France, 267 

dam and reservoir-site, 373-379, 391 

reservoir capacity, 375-379 

watershed, 374 
Villar dam, Spain, 254, 391 
Vingeanne dam, France, 256 
Visclier, Hubert, 280 
Volume : 

Agiia Fria dam, 206 

Little Bear reservoir, 371 

masonry, New Croton dam, 237 

of water for sluicing-heads, 76 
Vyrnwy dam, Wales, 262, 891 

Wagoner. Luther, 59, 62, 177 
Walnut Canyon. Ariz., 225 
dam, 214, 225-228 

Walnut Grove, Ariz., 58 

rock-fiU dam, 58-68 
Warner's ranch reservoir-sit*, San Luis 

Key River. Cal., 6 
Waste-weir, 131, 288 
Water cushion, 45 
Water-power, derricks, 161 
Water rights, litigation over, 293 
Watershed : 

areas, 392-408 

Barrett, 35 

Bear Valley, 178 

Chats worth dam, 48 

Denver Water Company's reservoir, 71 

Habra, 264 

Hemet, 168 

Little Bear Valley, 872 

Morena, 89 

New Croton, N. Y.. 237 

OUy Creek, 27 

Pecos River, 54 

Seligman. 222 

Walnut Canyon, 225 
Water-supply : 

Lake McMillan, 57 

Pecos River, 54 

Rio Grande River, 360 

Sante FeRy., 214 

sources in vicinity of San Diego, 371 
Weather bureau, U. S. data on precipita* 

tion, 57 
Wegmann, Edward, 118. 247 
Wells, A. M., 46 
Wells, L. W., 84 
Whiting, J. E., 261 
Williams dam, Ariz., 214. 224 
Wilson, H. M., 118, 122, 277, 278 
Wire ropeway used in construction of 

Hemet dam, 161 
Wood stave pipe, 90, 285 

used for siphoning canal across Rio 
Grande River, 859 
Wright law, 2. 19 
Wyoming, reservoir- sites, projected in,3i5 

Yellow pine, use of, for wood stave pi;^e, 

Zola dam, France, 120, 125, 255