Skip to main content

Full text of "The development of water power along the Potomac / by Andrew Dyne William"

See other formats

This folder also contained 2 maps and 1 chart that was too large to scan. 

file:///X|/Special%20Collections/purgatory/Phi%20MuAVilliam,%20Andrew%20Dynes/blueprint.txt[5/27/2011 4:55:10 PM] 


One standing on the "bank of the Potomac at Great 
Falls sees a great surge of water over the rocky river bed. 
He immediately wonders why the power of the rushing water 
is not utilized. 


The Potomac rises among the Allegheny Plateaus 
and Appalachian Ranges. Its waters gather in a main 
channel which crosses the grain of the country in a south- 
easterly direction. The river empties into a branch of 
Chesapeake Bay sixty miles above Cape Charles. 

The Potomac with its tributaries forms a trellis- 
ed drainage system. The tributaries enter the main trunk 
at right angles, and are all nearly parallel to one another. 
The main feeders are the Shenandoah, the Great Cacapon, and 
the South Branch. All of these enter from the south west. 
There is, in addition to these, the North branch which is 
the true head of the river. The minor tributaries are Wills 
Creek, Conococheague Creek, and Monocacy River. All of 
these enter from the northeast from Maryland. 

The Potomac is 350 miles in length. Washington is 
situated at the head of tide water, 116 miles from the mouth. 


Cumberland is 108 miles from Washington direct and 186 miles 
dy the river. Great Falls is nine miles above the head of 
tide water. 

The profile of the river is broken by numerous 
rapids. The largest at Great Falls has a drop of 90 feet. 
The drop from Harpers Ferry to sea level is 345 feet. The 
total fall from Cumberland to the District line is 60 9 feet 
in 192 miles, distributed as followsi/: 

Li stance Fall in 
in miles feet 

Cumberland, Md. , to Great Cacapon 

River, W. Va 69.0 178 

Great Cacapon River, W. Va. , to Williams- 
port, Md 38.0 102 

Willi amsport, Md., to Shepherdstown, W.Va.. 27.0 46 

Shepherdstown, W.Va. , to If- miles above 

Harpers Ferry, W. Va 10.0 7 

One and three-quarters miles above Harpers 

Ferry, W.Va., to S a My Hook, Md 3.0 39 

Sandy Hook, MA,, to Point of Rocks, Md 11.0 33 

Point of Rocks, Md. , to Aqueduct Dam at 

Great Fal Is , Md . 33. 5 53 

Aqueduct Dam at Great Falls, Md. , to tide- 
water at D. C. boundary line. 10.5 151 

Total 192.0 609 

1/ Senate Document Mo. 403, 66th Congress, 3d Session, p. 29 



The chief disadvantage of the Potomac as a power 
stream is the variability of Its flow. The United States 
Geological Survey has kept complete records of the river flow 
for 23 years. These figures show that the amount of water 
available for power fell as low as 653 second-feet in 1914. 
The average low- water discharge at the District line is 1,486 
second-feet. For approximately half the year 6,560 second-feet 
are available. At times of extreme flood the river has had a 
maximum flow of 348,000 second-feet. Its average flow is 
11,900 second -feet, but the flow is less than 3,000 second-feet 
20 per cent of the time. 

Outside of the variability of flow, the Potomac offers 
excellent inducements for development. Good rock foundations 
for dams can generally be found at small depths. As a rale, 
the banks are favorable, and there are several sites where the 
drop of large falls could be rendered available. In addition 
the banks of the river from Point of Rocks to Washington, a 
distance of 44 miles, are comparatively free from railroads. 
The cost of moving the tracks would therefore not prohibit the 

flooding of the land. Building materials are easily obtainable, 

and facilities for transportation are excellent. 

The only other drop In the river where the absence of 
railroads permits any large water power developments, is from 


Williamsport , Mainland , to a point 1-f miles above Harpers 
Ferry, West Virginia, a distance of 37 miles, with a fall of 
53 feet. No proposition has been made as yet for development 
here, owing to its distance from a market for the power. 


Despite the natural advantages which have been men- 
tioned, very little power has been developed from the river. 
The "Potowmack" Company was chartered in 1784 and under the 
leadership of George Washington dug five small canals. In 
1824 the present Chesapeake and Ohio Canal Company was charter- 
ed by Virginia, and the charter was confirmed ~by Maryland in 
1825. The company was allowed to sell or utilize its waste 
water for power purposes. Small mills at Williamsport and 
Seneca are supplied with power by the canal company. Surplus 
water is sold for power purposes to a plant on the West 
Virginia side at dam number five. Beyond this the canal com- 
pany has not developed any power. 

InlB39 the Legislature of Virginia granted a charter 
to the Great Falls Manufacturing Company for the purpose of 
manufacturing cotton, hemp, flax, and wool at Great Falls. 
Virginia took the lead in the development of the river al- 
though the Potomac lies entirely in the State of Maryland, 
The Jurisdiction of Virginia extends only to the low water 

mark on the Virginia shore. The company bought land in the 


latter State, fronting on Great Falls, and several islands in 
the river in Maryland. From 1839 to 1895 it made no efforts 
to develop the river power. 

In 1895 the Great Falls Power Company was chartered 
by Virginia and bought all the rights and land of the Manufac- 
turing Company except the claims against the United States for 
water it had previously diverted. In 1853 the Government had 
begun to seek a source of supply for water for the District. 
The aqueduct dam was completed in 1867 and the water supply 
was drawn from the Potomac, It was this diversion of water 
for which the Manufacturing Company reserved the right to 
seek damages. The Power Company has done no more to develop 
the falls than its predecessor, the Manufacturing Company. A 
proposed development involving a dam at Great Falls, failed on 
account of the refusal of the War Department to grant a permit. 


REPORT OF 1913. 

In 1913 two methods for developing the river at 
Great Falls were considered in a report submitted to Congress 
by the Secretary of War. This embodied the recommendations of 
the Army engineers, and is known as the Langfitt-Herschel re- 
port (House Document No. 1400, 62d Congress, 3d Session). 

The first plan was to bring the water from above the 
falls through a canal or head race to a power plant located on 
the bank of the river below the falls. The second method was 


to construct a dam at the District line. The power house 
wo ul a he situated at the Maryland side of the river and would 
be part of Hie dam. This plan would make use of the whole 
drop of 150 feet below the falls. 

The United States Engineers considered both of these 
proposals. They wished to combine a plan for increasing the 
District water supply with one to provide a power plant to 
supply electricity to the Government and municipal buildings 
and for street lighting. In developing the first method, It 
was proposed to construct an open canal from Great Falls to 
Dalecarlia Reservoir near the District line. The water for 
the District was to be drawn from the reservoir and the rest 
would be used to develop power at a plant situated on the 
river bank. This plan was abandoned since it was not economi- 
cally practicable. 

The second method of a dam and power house at the 
District line was considered more feasible. The elevation of 
the water surface of the lake formed by the dam would be 115 
feet above sea level. The dam was to be curved in order to 
get the required overflow area. Eighteen Stoney gates 65 feet 
wide and 25 feet deep were to be provided to carry off the 
additional water in flood times. The dam was to resemble in 
general features the Gatun Spillway dam of the Panama Canal. 
The water supply could be taken directly from the lake formed 
by the dam without an undue lift for the pumps. The power 
house would be built to the si«e required for the ultimate 


development, and the machines would he installed as they 
were required. 

The equipment for the power house was to be 12,500 
horse power turbines direct connected to 8,000 kilowatt gen- 
erators and working under an 111-foot head. The generators 
would deliver current at 13, 500 volts. A peak load of 
47,000 horsepower was expected in 1937. This load would re- 
quire four turbines. The initial installation was to have 
been three turbines, one acting as a reserve. The power 
house was to be designed and built to accomodate an ultimate 
development of nine turbines, these being installed as the 
need for more power arose. During dry periods the hydro- 
electric power was to be supplemented with power from a 
steam auxiliary. This auxiliary was made up of the power 
plants of the Government buildings, the main one being the 
Capitol plant with a capacity of 10,000 horsepower. 

Since it was planned to develop only enough power 
to supply the Government and municipal buildings and to 
light the streets, it would be necessary to instal a sep- 
arate distribution system. Later Army engineers decided 
that this additional cost would make the plan too expensive 
to be economically justifiable for the production of power 
in so small a quantity as the Governments would use. 

REPORT OF 1921. 
In 1920 the problem was taken up again. Congress 
ordered the Federal Power Commission to investigate the economic 


value of the power plant suggested in the 1913 report. A 
report was submitted early in 1921, which is generally referred 
to as the Tyler Report (Senate Document No. 403, 66th Congress, 
3d Session). The Commission studied the Longfitt-Herschel 
plan and several other proposals. The second plan studied in- 
cluded the dam at the District line with the addition of four 
storage reservoirs, which would maintain a constant flow of 
6,500 cubic feet per second, thereby permitting the development 
of 71,500 continuous horsepower. The third plan had much the 
same features as those included in the others. It was to have 
a dam at the District line which was straight instead of curved. 
In addition a second dam 75 feet high above Great Falls was 
proposed. The lake thus formed would be 39 miles long and 
would have an average width of about a mile. It would cover 
an area of 24,000 acres when it was full to the 215 foot 
elevation. This lake was to be used partly as a storage pool. 
For this purpose its surface could be lowered to an elevation 
of 180 feet. Its capacity between the elevations of 180 and 
215 was 500,000 acre-feet. For the eight month's period from 
December to August, the records showed that 10,000 cubic feet 
per second could be relied upon, permitting a development of 
186,000 horsepower. During the other four months the water 
would be lowered to give a continuous flow of 4,000 cubic 
feet per second. This would give 68,000 horsepower. Addi- 
tional storage, as in the second plan, was suggested when the 


power demand justified it. 

The War Department engineers concluded that a 
combination of the three plans would offer the most feasible 
solution. They decided that all the power between Point of 
Rocks, 3&j=r miles above Great Falls, and tide water should be 
developed by two dams, one at tide water and one above the 
falls, with power installations at both. The plan included 
head water storage to equalize the flow. The location and 
capacities of the storage reservoirs which were best suited 
for initial development are given in the following table: 

Location Storage in acre-feet 

Great Cacapon 400,000 

North Fork of Shenandoah 40 5,900 

South Branch of Potomac 464,700 

Total 1,270,000 

Other sites were rejected on account of the cost of the 'land 
that would have to be inundated, and lack of suitable sites 
for the dams as well as scarcity of building materials in 
the neighborhood. 

The main dams would be the same as those previously 
proposed. The District line dam would be straight instead 
of curved, since a straight spillway would be large enough 
to discharge the maximum flood on record. This change in 
the dam is due to the change in the Geological Survey's 


estimate of the crest discharge of the 1869 flood from 
470,000 cubic feet per second to 390,000 cubic feet per 

The upper dam was designed to permit a lowering 
of water from 215 feet elevation to 195 feet. This lower- 
ing of the level was to take care of flood waters and not 
to maintain a continuous flow, as proposed in the third 

The installation of machines would be sufficient 
to develop all the power from the "medium flow" of the 
river, 6,000 cubic feet per second. This would be about 
90,000 kilowatts at each dam, with an assumed load factor 
of 50 per cent. By supplying water from the three storage 
reservoirs and by using tine pool above the Great Falls dam 
as a reservoir the minimum flow through the driest period 
will become 6,000 second- feet. It would be necessary to 
draw the water down only 15 feet in the Great Falls lake 
to give the desired amount of water. Thus 90 t 000 kilowatts 
could be generated at each dam continuously. This amounts 
to 750,000,000 kilowatt hours per year of continuous power 
at the powerhouse switchboards. 


The development of 1he Potomac river offers great 
possibilities. When the river is suitably dammed and its 


flow regulated, it will yield a great deal of cheap power. 
However, it wuld require a huge investment of capital to 
develop it properly. It would render its maximum service 
as a part of the superpower project. This project involves 
interlinking hydroelectric and steam plants from Boston to 
Richmond. The hydroelectric plants are to be situated in 
the best locations on the rivers of this territory. The 
steam plants are to be erected at the mouths of coal mines, 
thus cutting out the cost of transp ortation of coal. As a 
unit of this system the variable flow of the Potomac would 
be forced to deliver the greatest amount of power at the 
lowest cos t. 



United States Geological Survey Water-Supply and 
Irrigation Paper No. 192 
The Potomac River Basin (1907) 

House Document No. 859, 60th Cong., 1st Sess. 
Examination and survey of Potomac River below Washington, D. C . 

House Document No. 1400, 62d Cong., 3d Sess. 
Water Supply of the District of Columbia and Water Power 
at Great Falls (1913). 

Senate Document No, 403, 66th Cong., 3d Sess. 
Development of Great Falls for Water Power and Increase of 
Water Supply for the District of Columbia (1921) 

United States Geological Survey Bulletin 689 
Boundaries, Areas, Geographic Centers, and Altitudes of the 
United States and the several States (1923) 

68th Congress, 1st Session - Hearings before the Sub- 
committee of the Committees on the District of Columbia on 
H.R. 4979 
Development of Hydroelectric Energy at Great Falls (1924) 

68th Congress, 2d Session - House Report 1247 
Parts 1 ana 2. 
Development of Hydroelectric Energy at Great Falls (1925). 

Water Power the Key to Virginia's Development 
(Published by the State Water Power and Development Commission, 
Richmond, Virginia, 32 pp. 1925). 

MrfP5 <*»<* /LL UJ TP/7T/OA/J 



M aryland and DC. 

West Virginia North Carolina 


The circles rep re sent the ls It 7 mate develop- 
ment fa utilize the potential water power of each 
$taf&. The cross hatched J ecfor-s r~&p/-esenf 
the ca pacify of wafer wheels /n pr/arrfs of 100 
hp. or more ir? Anarch, 1325. 

From Water- Power the tfeu to Virginia's 
P eve lop ment p. 25. 

Photo of Potomac ltlwr at Chain Bridge, looking downstream, August 5, 1B2-1. 

Photo of 1'utumuc RiviT looking ii|wtrv:im Iram Chain Bridge, August 3, 1924. 

River near pr-or°**J <*<*«> si + e "+ rhe 
GB+hCo^. 2ci$**. Hour* r*P°»*+ fZ«7 p*r+ Z. 

I ' i vi E [ 


Plate II 

'-~ Sfljr 

■ _^^ - ^" 'a 

' r«..^ilfcv^ r Jl^- 



~jj£ J91 


iln**. C ^ V J F A I*' . /fHH 

■ap-^-w -^-J f'^/ 1 . 

^^^ -Mate 


- ' 

fe Ira ' 


38085 3. Doc. 108, 88 3, (To face page 108.) 

War Department 

Corps of Engineers, U. S. Army 

33985 — S. Doc. 403, 66-3. (To face page 88,) No. 3 

War Department 

Corps of Engineers, U. S. Army 



tnll:»H*«t:> 5ho.tH.j4 Seal* 

PHjii ^ I m — - — 

un. u*H? O VMM' iDOv' 

U.3.Ef5gio*«r- Office Wctph i o<jto m D.C., Jan ID . IS'Z ! 

To d^company r*poc> «iJaijrcJ Jan J0 t 1*1* . 

33985— S. Doc. 403, 66-S. (To face page 88.) No. 4 

War Department 

Corps of Engineers, U. S. Army 



1W o E» - le*?" 

u .3. Engineer Olf.rir.WajhincjtoQ.P.C, Jen 10.192 I' 

S39SG — S. Doc. 403, «S-3. (To face page 88,) No. S 

War Department 

Corps of Engineers, U, S. Army 


■ ■ 

■ ■-•■■--■ - '■ ■; "'!■:"■.'_-* us 


Cross ■5<£cffO<"> 

'.y:-. (<■■ 

i ckj^'i ijj 1 -v y I'? 


_Exta *:m» fLped huejhl-KS"* 

Lowgf Baol at £ltt-v *H»5 

Pcvjcr heuftc Section 

Jfjpillwa^ S«efioO- 



u&Fn<]LT>a*r Offic*, *fa»Wftgt*0. OC, Jan, i0; 1921 
To otternpdcy riqwrt; dgrtffel Jon 10 „ tfJll . 

330 85— S, Doc, 403 t 00-3. (To face page 88.) No. C 

War Department 

Corps of Engineers, U. S. Army 

ff/P» ,te{<Mzd>ciG,\ Dam 
' Gnzcrf Falls 
Fbwer Dam 

Upp«:r Lwrji*- 01 Pbol^ 




l^^T^^^^ T "1 Ml. 

U. 3- tn^io« er Offic^W^ahm^^on, D,C f Jon 10, li9*H 

To occompetny rteg<tH _fJist<r d Jen 10, 1021 - 

339 85— S. Doc. 403, G0-3> (To fnco pjigc 88.) No. 7 

War Department 


















Corps of Engineers, U. S. Army 





in -1 v- l i.j\- t 

<*' f'jfl Oc*»l«"i' d) .>id.Lat«d 


■::■.:--.. s. Uik. ios, in; :;. it« r ;t ri> pi-r ws.i \ fl q 

War Department 

Corps of Engineers, U. S. Army 

Tftpe*J from U„3-GhEcI. 3«rv<y AcJ-nr,i *. 

3V?**t SffrjccT to correction 






To accompany f«p«trt_eiaV«^ Jan. 10 , kft&t. 

SS986 — S. Doc. 403, 66-8. (To face page 88.) No. 9 

War Department 

Corps of Engineers, U. S. Army 


Tr*ac*d from U 3. Q<xcA ^orv^y AcFiAfirtcc 


In 'T- ihc«^9 "jha-cf Nc m-> Scaler oi -,rn:j'c-a\*<i- 

33985— S. Doe. 403, 88-3. (To face page 88.) No. 10 



Summary , 1 

General History of Annapolis . 3 

History of Old City Hall 8 

History of The New City Hall 12 

Construction of Old City Hall 18 

Construction of New City Hall 22 

Drawings 30 

Pictures 33 

Bibliography 36