THE HISTORY AHD CONSTRUCTION OF THS POTOMAC DAM MS GREAT FAILS, MARYIAHD BY CONSTANT INS E. LOZUPONS +/27/34 -1- THE HISTORY AND CONSTHUCTION OF THE POTOMAC DAM AT GREAT FAIIS^MAHYLAND The romamce of the Great Falls of the Potomac embraces more thaa three eeaturles of American history. This spot of scemlc sple»dor, water supply, aad poteittial power has lomg beem a coveted prize, aftd title to the falls has beam a comstamt source of dispute. The earliest record of the falls is ia the gramt of Marylamd lamd to Lord Baltimore by Charles the First im 163S, The graat of the lamd imcluded the Potomac River of which the Great Falls are a part, im 1688 the gramt of Tirgimia lamd to Lord Culpeper by James II also imcluded the Potomac River. The real history of Great Falls begims with the close of the Hevolutiomary War whem Tirgimia gramt ed a charter to the '*Potowmaek Compamy" givimg it exclusive aavigable rights to the river. The presldemt of this compamy was George Washimgtom, The "Potowraack Compamy" built five eamals mear the falls but mever accomplished amythimg defimite Im the lime of mavigatiom* Om Jamuary £7,1824 the virglmia legislature revoked the charter of the "Potowmaek Compamy" amd gramted a mew ome to the Chesapeake amd Ohio Carnal Compamy, This charter provided that the water of the Potomac should forever be reserved to maimtaim the compamy 's carnal. The compamy had first rights to the river. The water which the carnal compamy did mot re- quire for mavigatiom purposes could be used by the govermmemt Great Falls of the Potomac, Maryland, 15 miles from WashlnBton, D. C. 1 Government [Vd n, Careat Falls of the Potomac, Maryland, 15 miles from Washington, D, C, The X'6 mark +he bouncloflet» o-f +Ue cl«t^ -3- or other emterprlses. The peculiar thimg about the charter was that virglmia had mo jurisdictiom over the Potomac amd hemce oo-uld mot give amy compamy rights to the river » Owmership of the river was defimitely settled betweem liarylamd amd Virgimla by agreememt. The gramt of torylamd lamd by Charles I im 1632 to Lord Baltimore was held superior to the later gramt of Virglmia lamd by James II to Lord Culpeper. It was defimitely deteraimed that the Potomac River is part of the state of Marylamd, the state lime beimg low -water mark om the Tirgimia side. But the fact that Virgimia im reality did mot have Juris- dictiom over the Potomac mever bothered the Chesapeake amd Ohio Camal Compamy. This eomcerm wemt over iato Marylamd amd om Jamuary 31,1825 had its Virgimla charter approved by the Old lime State, Later it had its charter approved by Pemasylvamia amd om K'lay 3,1825 had the agreememt to which three states amd the camal compamy were parties, approved by act of comgress. This is where the carnal compamy gets its perpetual rights to the Potomac. Its charter has be em held by the Supreme Court to be am agreememt betweem states which the Comstitutiom protects from impairmemt. No power save am ememy who might oomciuer the matiom cam take that right av^/ay from the compamy. Fortumately there has beem amd still is suffioiemt water to rum the camal amd supply the District of Columbia as well. The mext eomcerm imterested im the Potomac was the Great Balls Mamufacturimg Compamy, This corporatiom was chartered by Virgiflia om February 4,1639, It acquired about 750 acres of lamd om the Virglmia side of the river, just below the -3- falls a»d also about 61 acres of Coma's Island im the river, beimg the islamd across whose southern point the present dan exteads, Oa April 2, 1895 the Great Falls J/Iaaufactiiriag Co. sold Its fraachises, rights, aad real estate to the Great Falls Power Coapaay which had beea chartered by Virgimia ia 1894, Neither of these oompaaies accomplished aaythiag, their sole object seemiag to be holdiag the laad -uatil the goTerameat would aeed it for water works aad thea demaad aa exorbitaat price for it. ia 1853 the IJaited States first attempted to use the water of the Potomac by acquiriag iaterests at Great Falls, It obtaiaed the coaseat of Marylaad to tap the river for water supply that year, aad decided to use the lower ead of Coaa's Islaad for a dam exteading from the Maryland shore. At this time the Great Falls Maaufacturiag Compaay did aot owa Coaa's Islaad. It purchased the Islaad ia 1854 aad whea the goverameat started to put its water supply plaa iato operatioa it had to settle with the maaufaeturing eompaay, A jury assessed the daaages at $150,000, The award was atrocious whea it is coa- sidered that the Uaited States bought 130 acres about the falls for oaly $3,720, The laad ia quest ioa was a sn^ll strip across a sterile islaad 600 feet wide, it is sigalfieaat that from 1839 to 1853 the compaay had displayed mo sigas of actirity. As sooa as the goverameat begaa making plans for use of the river for water supply, the maaufaeturing compaay got busy buyiag Coaa's Island aad demaadiag aa exorbitaat price for the part of it the Uaited States had to have. The government refused to accept the award of the jury and for aeariy ten years the -4- oase was im litigatio*. Fi»ally, ia 1862, by agreemaiit, It was t-uraed orer to a oommissioa of fire lawyers, who rec- oameaded several plaas oae of whicti Involred tlie paymeat of $15,692 aad gave the goverameat the right to build a dam at Great Falls. The maaufactttriag compaay refused to accept the decisloa, but the Uaited States weat ahead aad built the daa aayway, completing it ia 1867, The compaay sued for $500,000 ia the Court of Claims aad la 1880 was giTea ^15,692, the e^Act amount of the award uader the plaa of the connlssioa. The maaufacturiag oontpaay appealed this case to the Supreme Court of the uaited States aad lost. The plaa adopted gave the Uaited States the right to build a dam across the ^larylaad Chaaael to Coan's islead, aad gave it the use of all the water the daa diverted, Prom 12,000,000 to 24,000,000 galloas per day were used from the time the dam was completed la 1867 uatil 1882 whea it was proposed that the Uaited ^states acquire add- itioaal water rights at Great flails to iacrease the water supply of fMshiagtoa. Ia 1882 Coagress passed a bill providiag for the acquisitioa by coademaatioa of sufficient laad to extead the dam from Conn's Island to the Virgiaia shore. The maaufacturiag compaay again put ia a big claim and tried to stop the work. The exteaded dam was completed ia 1886, but ia the meaatime, the maaufactiiriag compaay had filed a claim for $1,000,000, This was a soxirce of coatroversy for tweaty years aad was pressed by the Great Palls Power uompaay after that coacera took over the property aad fraachises of the maaufacturiag company ia 1895, This claim was fiaally settled ia 1902, the uaited States payiag damages of $63,766, The total sum which the governmeat has paid for -5- water priTileges at Great i-'alls, exclTisiye of its purchases of real estate, is as follows: Arbitratlo* iacpeases $ 12,761.84 Great ifalla Aamufactxirlag Co. 15,69 2.00 Great Fails I'ower Co. 63.766.00 Total $ 92,219,84 These paymemts, it must be co&sidered, were to eomcerms that had meTer dome aay of the thimgs for which they were ia corpora ted; that had Mever developed am o\mee of Great rails power diiriEg sevemty years of life; that had never performed a single public service. Yet whe» the govermmeMt wanted to utilize some of the water it had to pay them nearly $ 100,000, Previous to December 3, 1863 the aoiirce of water for the District of Col-ombia came from wells aad springs, very early it became apparent that such a supply would not be adeqiiate for the rapidly growing oity in coming years. Studies were therefore made of possibilities of using the Potomac River as a source of water. Surveys to ascertain the best method of supplying water to the city of Washington were ordered by President Pillmora. In February 1853, the report of Captain M.C.Meigs, who had been assigned to this work, was forwarded to Congress by President Killmore, The report recommended a gravity supply from the Great Falls of the Potomac some fifteen miles above "/Washington, by a conduit nine feet in diameter, capable of delivering more than 67,000,000 gallons per day. The population of Washington at that time was about 50,000 and of Georgetown, now west Washington, about 8,000. At that time Boston had a supply of 10,000,000 gallons per day. New York of 30,000,000, and Philadelphia of 15,000,000. CaptaiB. Meigs' orlglaal plan had to be modified 'several times because of legal obstacles, but finally bids were opemed Ik May, 18 58 for a riprap dam to extend from the hlaryland shore to Conn's Island. The contract was awarded to Dexter Belknap of New York on June 10,1858, The following was included in the speolfioations: 1. The dam is to be an embankment of rubble stone with a top width of SO ft., a slope on the upper side of one to one, and on the lower side of five to one. 2. It will be made with large stones, the spaces filled with smaller ones, so as to form a compact mass, 3. The eastern end of the dam (on the i-^ryland shore) will be connected with the head wall of the feeder. The western end will terminate against a ledge of rook. The terms of the contract were as follows: 1. For clearing trees, brush, and logs from the space flooded by the backwater of the dam and occupied by the dam $ 50 per acre 2, For the rubble stone deposited in the dam, including the cost of placing and packing in conformity with the specifications $ 1,30 per ou.yd. 3, ?or broken stone , including the cost of the stone, of breaking it, and depositing it in the dam $ 1.00 pet cu.yd, 4, Gravelling, including cost of depositing in the dam in accordance with the specifications 0.50 per ou.yd, 5. For excavation of rock in the boat channel above the dam or under the site of the dam $ 1,00 per cu.yd, 6. For excavation of gravel, earth, and loose stone in the boat channel above the dam or under the site of the dam $ 0.15 per cu.yd. This riprap dam was begun and built almost to the island. Difficulties in obtaining land rights on Conn's Island prevented Its completion. -7- Om June 16, 186S Comgresa traasf erred the aqueduot from the War Department to the Department of the iaterior. The Secretary of the Interior put William H, Hut ton in charge of the work and he was succeeded the following year by Silas Seymour. Seymour inunediately expressed his disapproval of the riprap dam and finally succeeded in submitting the question of replacing it with a masonry dam to Congresa, On July S, 1864 Congress appropriated funds for the erection of a solid masonry dam to extend from the Maryland shore to Conn's Island, The contract was awarded to Dunbar, Sherrlll, and Bangs on July 30 and work was started Immediately. Great difficulty mas encount- ered In obtaining laborers, owing to the high prices paid for substitutes to enter the army and to the fear of incursions from guerilla parties of Confederates, Considerable progress was made In spite of delays caused by the CItII War and the work was eompleted September 30, 1867, During actual construction riprap diversions were used to fiirnish water, Exerpts from the specifications follow: 1. Foimdation to rest on rock wherever practicable. S, The masonry in the foundation Is to extend from the rock foundation up to the level of low-water mark of the river. The lower face will have a slope, either in steps or batter, of two feet base to one foot rise, and upper face in steps of one to one. 3. The lower or front face of the superstructure will be vertical, the rear or downstream face will batter in the ratio of four inches to the vertical foot, 4. The top of the dam will be 7 ft, thick and it is to be of rubbla cement masonry, 5. The ooplng will be of Seneca sandstone. 6» The rear angle formed by the back face of the dam and the bed of the river will be filled with good coarse gravel or broken stone, extending from the top of the daTO with a uniform slope not greater than 3 ft. horiz- ontal to 1 ft, vertical until it reaches the bed of the river. .B- The terms of the eo» tract were as follows: For cleari»g & grubbing the entire work ^ 1800 For exoaTatiom i» foundations 2,50 per cu.yd. For concrete & grout in foundations 6,00 per cu.yd. For foundation nasonry 14,00 per cu.yd. For superstructure masonry 14.00 per cu.yd. For coping 20.00 per cu.yd, J?'or wrought iron in bolts & olamps 0.15 per lb, For back filling 3,50 per cu.yd. The crest eleTatlon of this dam was 147,0 feet with mean low tide at the Navy Yard in Washington as a datum. It was completed at a total cost of ^ 50,000, A rapid increase in the water consumption of the city of Washington soon made it apparent that this solid masonry dam was not high enough to Impoimd the necessary water to meet the new requirements. In 1881 it was found that for 257 days of that year the water at to eat Fills was below the leTel necessary for adeqiiately supplying the District of Columbia, Temporary dans at the head of Oonn'8 Island were built to meet the emergency but these, besides being washed away each spring, did not meet the situation. The problem was submitted to uongrese repeatedly and finally, on July 15,1862, an appropriation was made to finance the raising of the existing dam to an eleration of 148. Q and to extend the whole structure to the Virginia shore. The contract was awarded for this work on Not ember 7,1883 to the Chittenden Bros. The old dam across the Maryland channel was raised by putting a coping on it 15 inches in thickness. The length of the old dam was 1034 feet. The extension included a length of 669 feet across Conn's Island and 1174 feet from Gonn*s Island to the Virginia shore. The new dam was to be a masonry structure composed of large cut stone for the facing and backing , with concrete filling, A flood which occurred the night of October 29 and 30,1885 destroyed the coffer dams which had been built and submerged the entire work. When the coffer dams were -9- restored, it was fo-u»d that the flood had tora out from the dam 10-j^ ou.ydB, of eoaorete, 27f on, yds, of out stoae, aad 33^ ou.yde. of eopiag which had Just beea put la place but act bolted. No damage whaterer was doae to aay portloa of the completed dam im which the mortar had had a ehaaoe to set. The damage was repaired aad the work was fialshed oa August 31,1686 at a total cost of $ 140,4B5.48, The completed dam had a total leagth of 2877 feet amd raried ia height from 4 to SO feet, the deepest part belag Im the Virgiaia chaaael. The width of the dam la the Marylaad ohaamel was 7*- 9** while across Coaa's Islamd aad the Tirglala chaaael it was 8'- 3**. Ob Juae £,1889 a great flood occurred and the water rose to a height of 16 feet above the crest of the dam. 1103 feet of eopiag was washed off aad deposited ia the pool below. The damage was repaired duriag the fayorable seasoas of 1890 aad 1891 at a cost of $ 9000. The stoaes were replaced aad fasteaed with iroa bolts fire feet loag aad two laches la diameter with heads oa them of Buffioieat stremgth to preTeat the stoaes from sllppimg off. Whea the dam had beea ezteaded to the Ylrgiaia side It was thought that it would Impouad eaough water to supply the city of Washiagtoa for all time. This was sooa fouad to be a mistake. Prom 1886 to 1894 coasumptioa rose from 25,000,000 galloas per day to 49,000,000 galloas per day while the populatioa lacr eased oaly 30?&. The eleyatioa of the dam was partlcxilarly fouad to be laadequate duriag low stages of the rirer. Oa Uareh 2,1895, a sum of $ 185,000 was appropriated to raise the eleratloa of the dam to 150.5 feet. This was doae by remoTiag the stoaes, iaoreasiag the height, aad replaclag the eopiag. The ooplag was fasteaed with bolts 2" ia diameter aad about 7' ia leagth. This work was -10- eaupleted i« NoTember 1896 at a total cost of $ 101,373, This was tlie last masomry corns true tiom dome om the dam. There has beem mo serious damage slmce them, the omly repairs belmg replacememt of the loose riprap baokimg which is partially carried away by the ammiial sprlmg freshets. After the hydro-electrlo plamt at Bale carl la was placed Im serTicft im 1928, the Tclmae of water meeded was more tham doubled. Flashboards of Douglas Fir were used to solve this problem. These plamks are 12" high amd 2" thick. They are held im place by 2" black Irom pipe stamdards set im holes drilled la the coplmg four feet om cemter. The cost of this work which was completed im 1930 was $ 2,394.47. These flashboards brought the elevatiom of the dam to 151.5 feet which is Its presemt elevatiom. Today the dam stamds im perfect oomditiom with every imdieatiom that it still possesses years of good service. The presemt value of the dan based om cost of reproductlom is $ 450,000, A summary of the cost of the dam follows: Cost of lamd amd water rights $ 112,275.96 Cost of oomstruotlom 311,321.77 Total cost of aquisitlom $ 423,697.73 Source of fumds: limited States I 289,168,87 District of Columbia 134.428.86 Total ¥ 423,697,73 -11- TYPlC^L SEICTION OF DAM AT GREAT FALLS icaie I" = 4- WidtW o^ dam across Marylan4 CKani-iel - WiclH\ across Conn's Is lamd K \/a. CKannel = HeigM o-f do.rr' va»-ics ^vowvi -4^ ■" 2.0' Average Wel^U-t ■= 15' 7'- 9" Len9i"W of dann ■• Across Marv^^Qnd Cho^v^^r^et Across Conn's Islav^d Acf'oss Vit-ginia CWannel To4al Length I0 34- f+. Eleva + ioi^ of +op o-f -flavin- \ooards = 1 5 (. 5 fl. above VTaeairt low -Vvdie. at tUe Wavv^ Yord \vi VV a^U vk^gt on ,\), C, i^ / Xhe new m^ake a^ Gre<\^ Fftl\s,Md. ^Tt. A view o-f tlie ci Owi '^^^e ol<i i.^4ak( i/ \ ; I 23 A pat-V o-f +tie Cc O CaM< -12- WaTER-SEED of the POTOMAC AT GREAT FALLS, MARYLAND The dral»age area of the Potomac RiTer at Ureat l?*all8 Is equal to 11,460 square niles* -13- YEARIiY DISCHA.HGE OF THE POTOMAC HIYER AT GHSAT ?ALLS soar uazlnnn MlKln^ra M«am 1897 202,000 2300 13.700 1898 12S»000 1870 11,500 1699 132,000 1,790 15,500 1900 58,900 1,200 7,730 1901 169,000 1,150 14,300 1902 248,000 1,470 16,100 1903 123,000 1,840 17,300 1904 43,300 1,520 7.980 1905 76,500 1,070 8,270 1906 94,500 2,120 11.400 1907 131,000 2,970 16.600 1908 161,000 1,770 17.000 1909 82,400 1,440 7,750 1910 172,000 1,020 9,240 1911 119,000 828 7,690 1912 94,800 1,940 13.800 1913 143,000 848 9,500 1914 77,700 653 12,200 1915 141,000 775 11,800 1916 14R,000 1,310 12,400 1917 133,000 923 9,480 1918 126,000 1,060 11,200 1919 72.400 1.280 10.000 irg« for t^® 248,000 653 11,900 All discharges giv»M ia cuble ft. per seooad. Dralaage area of the Potomac RiTor at Great i<alls Is 11,460 eg.. mis. The discharge of the aqued-acts at Great ^alls Is seldom greater tham 400 e.f.s. 23 year period The above flgxires show that the average discharge of the Fotosiae OTer a period of 23 years was 11,900 cable feet per seooad. Srea the mialrn'oii of 653 c.f.s. is more thaa what is used by the aqueducts. -14- Am iaterestimg report submitted by the U.S. Geological Survey im 1913 reveals some decisive figures. The data follovs. All figtires beyomd 1912 are estlinatds. lear Popnlatlom Average Daily Comsunptiom Mazlmiim Dally Com STimpt lorn 1906 323,000 68,700,000 (gallomsl 1906 326,000 67,400,000 1907 330,000 66,900,000 80.290,000 (gallons) 1908 339.000 64,910,000 80.380,000 1909 343,000 61,470,000 78,930.000 1910 343,000 54.190,000 78.600.000 1911 348,000 60.360,000 78.320,000 1912 354,000 62,120,000 92,720,000 1915 378,000 66,000.000 86,000.000 1920 406.000 70,000,000 91,000,000 1930 460,000 79,000,000 103,000,000 1940 515,000 89.000,000 116,000.000 1950 570,000 99,000,000 129,000,000 The discharge of the Potomac rtlver from fifteen years observation varies froBi 600,000,000 to 84,000.000,000 gallons dally. As the predicted maximum daily consumption in 1960 is only 129.000.000 gallons, it may be stated that the ir'otomac Hiver at Great Palls can furnish for all time a sufficient water supply to the District of Columbia. -15- BIBLIOGRAPEY AmBxial Reports of the tJ.S.Office of the Washimgtom Aqueduct Com^esslo»al Reports om DeTelopmemt of Power at Great F&lls Report of Major Tyler om Derelopmemt of Power at Great Slalls Differ emt Issues of the SmglmeerlKg News Imformatiom was also obtaimed from the Uaited States Coast amd Geodetle SuTTey, the Umlted States Geological SuTTey, the Corps of Emgimeera of the Umited States Army, amd from people lirim^ mear the Great i^alls. Corns ider able Imformatlom was obtaimed from Ur. Eardy who Is Im charge of the Dale carl la Reserrolr amd flltratiom plamt amd who also has dome mueh work om the dam, I am Indebted also to Mr, Moffeems,who is im charge of the McMillam Park Reservoir im washimgtom, for much imformatiom.