Development of the Columbia Basin Reclamation Project

DEVELOPMENT OF THE COLUMBIA BASIN RECLAMATION PROJECT Otis W. Freeman Eastern Washington College of Education, Cheney The Columbia Basin Project, situated in central Washington, has two primary purposes : the production of hydroelectric power and the reclamation of arid lands. By regulating the flow of the Columbia River, the hydroelectric works associated with the project have also improved navigation on the river, and have helped to prevent floods. All these purposes will apparently be gained without damaging the important salmon fisheries on the Columbia. Physical Setting The project lies in the Columbia Intermontane Province, between the Rocky Mountains and the Cascades. The area is underlain by basalt flows, which are locally interbedded with lake deposits and other terrestrial sediments . In places, the thickness of the lava and sediments exceeds 5,000 feet. Superficial deposits left by running water, winds, and glaciers often mask the bed rock, and the soil is generally derived from these transported materials rather than from the underlying hard rock. Except for some high hills, most numerous near the margin of the area, the lavas of the Columbia Basin formed a plain. Following the period of vulcanism, the lavas were warped and folded. The downwarps determined the position of the Pasco and Quincy basins, the principal areas to be irrigated. The upfolds form many ridges to the south and west of the central plains; two of these ridges, Saddle Mountains and Frenchman Hills, extend east of the Columbia River and nearly separate the Quincy from the Pasco Basin (Fig. 1). The Columbia River crosses central Washington in a roundabout course, in such a manner as to enclose the Big Bend country on three sides. The southern part of the Big Bend country includes the territory to be irrigated in the Columbia Basin project. On the north of the Big Bend, the eruptions of lava forced the Columbia River to flow along the southern edge of the Okanogan Highlands, where it has incised itself in deep gorges floored with granite. These gorges provide excellent dam sites. During the Glacial epoch, lobes of ice moved south from Canada into the Big Bend country and the region about Spokane. The ice blocked the Columbia to form a lake about 1,500 feet deep, the overflow from which eroded the Grand Coluee. I have named this body of water Lake Nespelem. Farther east a part of the glacier, and in the absence of ice the glacial meltwater, overflowed the divide that here lies only a few miles from the Columbia and Spokane valleys. Huge torrents or giant sheet floods cascaded southward, descending nearly 2,000 feet in a little more than 100 miles before tumbling into the Snake and lower Columbia Rivers. Erosion by the floods of meltwater removed the surface soil from wide strips of country, and exposed the bare lava. The pioneers called this denuded lava "scabrock." J Harlan Bretz has called this curious country "The Channeled Scablands," and has described it in numerous papers. Débris eroded from the scablands was in part spread out over the Quincy and Pasco 16 Yearbook of the Association Vol. 9 GRAND COULEE DAM GRAND COU EQUAUZING RESERVOIR SOUTH DAM MAIN CANAU LONS LAKE. FALLS IÔ3 FOOT POWER 0ROP Lake Roosevelt UMPING PLANT FEEDER CANAL NORTH DAM SOAP LAKE SIPHON Coulee City BACON SIPHON BACON TUNNEL rail Lake LONG LAKE DAM CANAL ^DEVELOPMENT FARM N?l OUINCY Olincy WASTEWAY Wheeler L»ke POTHOLES AM Warden POTHOLES WEST Beverly jSmyrnaOthello Saddle Mountain," unnlnqham AHLUKE SLOPE LATERAL Connell LEGEND Eltopia Canals ^??7------< Siphons Towns PASCO PUMPING PLANT BURBANK PUMPING PLANT FIG. 1. General map of the Columbia Basin Project. (United States Bureau of Reclamation .) basins. These deposits are level or gently sloping, and constitute superior soils for irrigation. Some deposits of coarse gravel and windblown sand within the basins are unsuited for cultivation, as are also exposures of bare rock and certain elevated ridges. Of some 2,000,000 acres included in the Columbia River Project, about 1,000,000 acres are considered tillable. 1947of Pacific Coast Geographers17 The scabland channels, which are often followed by railroads and highways , will be utilized in part for reservoirs and irrigation canals. The Columbia Basin lies in the lee of the Cascade Mountains, and receives no more than six to ten inches of rainfall annually ; too little, except in very favorable years, for profitable wheat growing by dry-farming methods. Irrigation is therefore a requisite for the dependable production of crops. Other features of the climate, however, such as a high percentage of possible sunshine in summer, and a growing season that ranges from 150 to more than 200 frost-free days, are favorable for agriculture. The Columbia River, the annual discharge of which exceeds that of any other western river, provides an inexhaustible supply of water for irrigation . Most of the best soil within the area of the project is, however, situated so high above the river that individual pumping installations are too expensive. A Grand Coulee Dam and the biggest pumps ever built are required to make irrigation practicable. The average annual discharge of the Columbia is 79,000,000 acre feet, five times that of the Colorado River at Hoover Dam. Grand Coulee Dam Grand Coulee Dam was begun as a project of the Public Works Administration , which in July, 1933, allotted $63,000,000 for the construction of a "low" dam 177 feet high, suitable only for hydroelectric power. Excavation was begun, but in 1935, before any concrete had been poured, plans were changed, and the height of the proposed dam increased in order to serve the purpose of both power and irrigation. Supervision of the construction was transferred to the United States Bureau of Reclamation , and the work of building the dam and powerhouses continued day and night. The first turbine-generator, of 144,000 horse power, was installed in 1941; by 1947 six such generators were in operation, and three more were soon to be completed. All these are in the power house at the west end of the dam. Nine more generators will be installed in a second power house at the east end. Congress has already appropriated funds for three of them. The planned capacity of Grand Coulee Dam is 2,600,000 horse power (1,944,000 kilowatts), of which one-half will be available early in 1948. During the war, power from Grand Coulee was used for the smelting of aluminum and magnesium, in aircraft factories and shipyards, and in the manufacture of plutonium for the atomic bomb. The dam is built at the head of Grand Coulee, on a foundation of firm granite. It is 4,300 feet long, 500 feet wide at the base, 30 feet wide at the top, rises 550 feet above the lowest bed rock, and contains 11,250,000 cubic yards of concrete. It has an effective head of about 300 feet. Behind it, Lake Roosevelt extends upstream 151 miles to the Canadian boundary; the elevation of the river at the boundary was the factor that determined the height of the dam. The site of the dam was chosen in preference to other possible sites because of the ease with which water from Lake Roosevelt can be pumped up 280 feet to an equalizing reservoir in upper Grand Coulee, from which it will flow to irrigate the Columbia Basin. Other advantages of the site were proximity to great deposits of sand and gravel for concrete, and to space in Rattlesnake Canyon for dumping more than 20,000,000 cubic yards of overburden that had to be removed from above the granite before any concrete could be poured. The Columbia River has 18Yearbook of the AssociationVol. 9 its season of high water in summer, when the requirements for irrigation water are at a maximum. Its discharge is so great that all needs for water can be supplied without any seasonal diminution of the output of power. The level of Lake Roosevelt will remain uniform throughout the year. The lake and its shores can therefore be conveniently used for recreation. The federal government has retained ownership of a strip of land along the entire shore line of Lake Roosevelt, so that the recreational use of the lake can be completely controlled, and unsuitable resorts excluded. Grand Coulee Dam itself, incidentally, is a major tourist attraction ; 340,000 persons visited the dam and power house in 1947. The large quantity of cheap hydroelectric power available from Grand Coulee, which will be available in the near future, is a great attraction to industry. The sale of power makes the Grand Coulee Dam and its power plant and distribution system a self-liquidating enterprise. Increased industrialization will help provide markets within the Pacific Northwest for much of the farm produce that will come from the lands to be irrigated. FIG. 2. Upper Grand Coulee, site of the Equalizing Reservoir. The Irrigation Project The irrigation works now under construction will consist of the following parts: 1, a main pumping plant at Grand Coulee Dam; 2, the Equalizing Reservoir, 27 miles long, in the upper Grand Coulee, held by two dams built of earth and rock, North Dam and South Dam ; and 3, a distributing system that will receive water from the Equalizing Reservoir. The distributing system will include two dams of earth and rock, Potholes and Long Lake Dams, and a main canal, which will bifurcate into a West Canal 80 miles long and and East Canal 130 miles long. The latter will also serve the southern section of the project. Potholes Reservoir is a part of this system, but it will also capture some runoff and drainage water, and will furnish water to land lying west and south of it. The irrigation system is the largest single installation of its kind ever planned in the United States. The pumping plant will use power generated at Grand Coulee Dam. The pumps will be installed in a wing dam upstream from the power house at the west end of the Dam. There will be 12 pumping units, in each of 1947of Pacific Coast Geographers19 which a pump having a capacity of 1,600 cubic feet (12,000 gallons) per second will be driven by a 65,777-horsepower motor. Any one of these units could supply all the water required by the city of New York. The water will be lifted 280 feet, through conduits cut in solid granite, into the Feeder Canal, which will be 1.6 miles long, 25 feet deep, 125 feet wide at the top and 50 feet wide at the bottom. The Feeder Canal will carry water to the Equalizing Reservoir, which will be held by earth-fill dams at the northern and southern ends of upper Grand Coulee (Fig. 2). The Equalizing Reservoir will be 27 miles long and 1.5 miles wide, and will cover most of the floor of the upper Grand Coulee. Its active storage capacity will be 700,000 acre feet. The railroad and highway that now traverse the floor of the Coulee will have to be moved to higher ground. Steamboat Rock, a landmark in the widest part of the Coulee, is expected to become an island. North Dam, 1.5 miles from Grand Coulee Dam, will have a maximum height of 115 feet above the lowest foundation rock, and a length of about 1,400 feet. South Dam is under construction near Coulee City. It will be 10,000 feet long, 65 feet high, 450 feet thick at the base and 42 feet wide at the top, and will carry a highway. Both dams will be built of earth and rock over a core of concrete five feet thick, which fills a trench cut into the bed rock and rises several feet above the original surface. Clay, sand, and gravel are added, and compacted with heavy rollers while wet, to prevent seepage. An outside facing of rock will protect the dam from erosion by waves. From the eastern side of South Dam the Main Canal will carry water southward to the Bifurcation Works near Adrian, where it will be divided between the East Low Canal and the West Canal. The Main Canal is about 20 miles long ; because of the large amount of excavation of rock required, it will be expensive. At the north, the canal traverses hard basalt for 1.3 miles ; a part of this stretch will be lined with concrete. The maximum cut is 90 feet, the top width 120 feet, and the bottom width 50 feet. The canal will convey a stream of water 36 feet deep, to irrigate 1,000,000 acres of land. Next comes the Bacon Siphon, of reinforced concrete, 1,000 feet long and 23 feet in inside diameter, which will carry the water across a dry canyon into Bacon Tunnel. This tunnel will be cut for two miles through hard lava, will be lined with concrete, and have a finished diameter of 23 feet. The contract cost of the siphon and tunnel is $3,394,000. For four miles after passing the tunnel, the Main Canal follows a natural channel, which is dry most of the year but is called Trail Lake. This part of the Main Canal ends on the rimrock above Long Lake Coulee, where the water will plunge 165 feet into Long Lake. It will thus recreate a waterfall that vanished at the close of the Glacial Period. Ultimately, the East High Canal will take off above the falls and irrigate 200,000 acres now used for dry-land wheat farming. Construction of this canal has been indefinitely deferred, in part because high prices for wheat and rainfall above the average since 1940 have led to the withdrawal of a large part of the privately owned land intended to be irrigated from it. If it is ever needed, a good deal of power can be generated at the artificial falls. Long Lake Dam, near Stratford, is not a storage dam, but a part of the Main Canal. Its purpose is to save 5.5 miles of difficult and costly construction, mostly in hard rock, by blocking a canyon at its mouth. The dam will be an earth-and-rock fill 1,900 feet long, 600 feet wide at the bottom, 20 feet wide at the top, and 130 feet above the lowest bed rock. 20Yearbook of the AssociationVOL. 9 It will cost $1,770,000. The present three small lakes in Long Lake Coulee will become a substantial body of water 5.5 miles long with an average width of one-third of a mile and a maximum depth of 100 feet. From Long Lake Dam the Main Canal (Fig. 3) runs southwestward 6.6 miles to the Bifurcation Works. Here the canal is 120 feet wide at the water surface and 50 feet wide at the bottom. It is planned to carry a flow of water 21 feet deep, sufficient to irrigate 800,000 acres. At the Bifurcation Works the West Canal and East Low Canal diverge. The West Canal, 88 miles long, will supply 281,000 acres, mostly in the Quincy Basin. It winds along near the northern and western boundaries FIG. 3. Excavating the Main Canal, near Stratford. (United States Bureau of Reclamation .) of the project to Frenchman Hills, and will pass through them in a tunnel 9,150 feet long, to irrigate the Royal Slope on their southern side. The contract cost of the first 6.5 miles of the West Canal, including two siphons having a combined length of more than a mile, is $2,871,796. The siphons, known as Dry Coulee Siphons 1 and 2, will be 25 feet in diameter, and the largest in the Pacific Northwest. The waters of the West Canal will be carried across the lower Grand Coulee north of Soap Lake by Soap Lake Siphon, 12,000 feet in length, which is not yet under construction. The East Low Canal will be 130 miles long, reaching nearly to Pasco, and will irrigate 252,000 acres. The first section, 12.3 miles long, is under construction at a contract cost of $3,977,000. The parts lined with concrete will have an average width of 76 feet at the water surface, and 20 feet at the bottom. The unlined parts will have larger dimensions. Concrete construction , where required, is facilitated by an abundance of sand and gravel deposited by flood waters during the Glacial Period. 1947of Pacific Coast Geographers21 Potholes Dam, near the center of the project, will be the largest of the four earth-fill dams in the system, and the fourth longest dam in the United States. It will contain 9,200,000 cubic yards of material, and its contract cost is $9,359,000. Its length, along an irregular east-west trace, is 3.5 miles, and its maximum height more than 200 feet above bed rock. Potholes Reservoir will cover 47 square miles. It will back water into Moses Lake and raise the level of that body of water by five or six feet. Its shoreline will be 250 miles long. This reservoir will have a capacity of 615,000 acre-feet of water, of which 250,000 can be used for irrigation. It will be supplied from both the West Canal and the East Low Canal, but will also receive drainage water from the northern part of the project for redistribution. Two canals lead from Potholes Reservoir. Potholes East Canal will reach almost to Pasco, and will serve 254,000 acres. This area includes the Wahluke Slope on the southern side of Saddle Mountains, to which water will be led through a branch canal. Potholes West Canal will supply water FIG. 4. Scene on demonstration farm near Moses Lake. to 13,600 acres along the base of the Royal Slope south of Frenchman Hills. The Potholes area contains many sand dunes; some of these will be inundated, but others will make excellent beaches for recreation. Approximately 12 miles north of Pasco, a pumping plant and a system of lateral canals are almost completed. Here 5,360 acres, divided into 76 farm units, will receive their first water early in 1948. Most of the land is privately owned, but a few farms will be sold by the federal government. Another pumping plant and system of canals, which will serve 4,500 acres divided into 74 farms, will be constructed along the Snake River at Burbank , a few miles east of Pasco. Both these small units will ultimately be supplied with water from the main distribution system of the Columbia Basin, and their pumping plants will then cease operations. Settlement The Bureau of Reclamation has made very complete plans for the settlement of the area included in the Columbia Basin Project. In order to demonstrate methods and crops suited to the local conditions, a number of experimental and demonstration farms have been established in several parts of the project and on different soils (Fig. 4). Various methods of 22Yearbook of the AssociationVol. 9 applying water will be tried, and the most desirable frequency and duration of applications of water investigated. Proper leveling, layout of ditches, and erosion control will be demonstrated. Various fruits, vegetables, and field crops will be tried out. Machinery will be tested, and its efficiency and adaptation to local conditions determined. The land has been classified into three general groups. Land of Class 1 has deep, loamy soil, and slopes not exceeding five per cent. It is suited to the production of irrigated row crops, such as potatoes, sugar beets, and truck crops, and of alfalfa. Land of Class 2 has less deep and fertile soil, or slopes up to 10 per cent. Class 3 includes inferior land, mostly suited to hay and pasture. Farm units as laid out by the Bureau of Reclamation are often irregular in shape, and one unit may include all three classes of land. It is estimated that there will be about 25,000 farm units in the project. Ninety per cent of the irrigable land is privately owned. No land is available for homesteading. Settlers will buy land from the present owners, or from whatever non-profit agency may be formed for the purchase, layout , and resale of the land. Present owners of land in the project will be allowed to retain one family-sized unit, up to 160 acres. Land owned in excess of the family unit will not be eligible for delivery of water unless it is first sold to the federal government. The price of land is based on its worth as desert land ; the value of most of it is between five and ten dollars per acre. Land suited to production of wheat under dry-farming methods has a market value that ranges upward to $30 per acre. All land in the project is subject to restrictions aimed to prevent speculation. Land may be bought or sold only after it has been appraised by the Bureau of Reclamation . New settlers are not encouraged to buy land until the time when water can be delivered. Construction costs for irrigation are expected to average $85 per acre. No charge for repayment will be levied during a development period of about ten years. Costs will then be amortized over a period of 40 years. The cost of Grand Coulee Dam will be met by the sale of power in less than 50 years. The cost of the entire project has been estimated at approximately $400,000,000, of which the sum of $262,000,000 has been allocated to power. Experience shows that a settler should have between $5,000 and $10,000, or its equivalent in implements and live stock, to make proper use of the average farm unit. It is expected that water can be delivered to a part of the area by 1950. Settlers will receive, from appropriate agencies, assistance in the production and marketing of their farm products. Settlement of the project will not be done at random, but will proceed by selected units over 25 or more years. Such a procedure will make possible the orderly establishment of means of transportation, market towns, schools, and other facilities , as the several parts of the project are made available, and will obviate the hardships associated with pioneer settlements in the past. It is expected that 125,000 to 150,000 persons will live on the approximately 25,000 farm units in the area, and that probably twice that number will be engaged in business and service occupations in the supply towns and market centers scattered through it. At a reasonable estimate, the Columbia Basin Project will add a half-million people to the population of Washington in the next 50 years. ...