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Washita Basin Project
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Washita Basin Project History (101 KB) (pdf)
General Description| Plan| Development| Benefits
General Description

The Washita Basin Project is in the Washita River Basin in southwestern Oklahoma. Principal features of the project are Foss Dam and Reservoir, Fort Cobb Dam and Reservoir, and appurtenant works to provide a domestic, municipal, and industrial water supply for several cities and towns in that section of the State. The project also contributes flood control, recreation, and fish and wildlife benefits.

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Foss Dam and Reservoir, on the Washita River in Custer County, provides regulation of the river flows and municipal and industrial water supplies for the cities of Clinton, Cordell, Hobart, and Bessie, Oklahoma. The water is transported from the reservoir to the project cities through 50.8 miles of aqueduct and laterals, three pumping plants, and chlorination and other facilities.

Fort Cobb Dam and Reservoir are on Pond (Cobb) Creek, a tributary of the Washita River in Caddo County. The facilities regulate runoff to furnish surface water supplies for the municipal and industrial water requirements of the city of Anadarko and the Western Farmers Electric Cooperative near Anadarko. Water is conveyed from the reservoir through a 20.9-mile-long gravity-flow aqueduct system.

The authorizing act for Washita Basin Project, Public Law 419, 84th Congress, included provision for the storage, regulation, and distribution of irrigation water for 26,000 acres of land, limited to a 10-year period from the commencement of delivery of municipal water from the reservoir on which the irrigation unit is dependent. Repayment negotiations for irrigation development downstream of Fort Cobb and Foss Reservoirs were not successful; therefore, no irrigation facilities were constructed.

Facility Descriptions

Foss Dam is on the Washita River approximately 15 miles west of Clinton, Oklahoma. It is a zoned earthfill structure with a crest width of 30 feet and a crest length of 18,120 feet. The structural height is 142 feet with 10,638,430 cubic yards of embankment, at top of flood pool level.

Foss Reservoir has an area of 13,141 acres. Total capacity of the reservoir is 436,812 acre-feet. The uncontrolled morning-glory spillway is at the right abutment of the dam.

Fort Cobb Dam is on Pond (Cobb) Creek about 5 miles north of Fort Cobb, and roughly 5 miles above the confluence of Cobb Creek with the Washita River. The dam is a zoned earthfill structure containing 3,569,185 cubic yards of embankment. The crest width is 30 feet, and the crest length is 9,900 feet. The structural height of the dam is 122 feet.

Fort Cobb Reservoir has a total capacity of 143,740 acre-feet and covers an area of 5,956 acres at top of flood pool level. The uncontrolled morning-glory spillway in the left abutment consists of a concrete intake structure, concrete conduit, and concrete chute and stilling basin.

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The first non-Indian settlements in the area were small scattered trading posts and military posts. Fort Washita was founded in 1842 on the east bank of the river about 22 miles above its mouth, Fort Arbuckle in 1851 near Wildhorse Creek in southern Murray County, and Fort Cobb in 1859 at the mouth of Pond (Cobb) Creek. About 1865, the cattle industry became a factor in settlement of the area. During the Civil War, vast herds of cattle had accumulated in Texas and at the end of the war many were driven across Oklahoma to shipping points in Kansas. One of the principal routes for these drives was the famous Chisholm Trail, which originally extended from Anadarko, Oklahoma, to Wichita, Kansas. The men conducting the cattle drives became interested in the large areas of grazing lands in this territory and leased from the Indians extensive acreages on which ranch operators and their crews became established. Following passage of the Organic Act of 1890, the Oklahoma Territory was organized. The Cheyenne and Arapahoe Tribes were given allotments of land, and unallotted lands in Roger Mills, Custer, and Washita Counties were opened to entry in 1892.


Irrigation in the Washita River Basin has been practiced for at least 30 years. The irrigated acreage in 1945-1946 was approximately 15 percent of that irrigated during the 1934-1940 drought period. With the wet years of the 1940`s, irrigation declined. Surveys were made of the water supply facilities of 35 towns and cities in or immediately adjacent to the Washita River Basin.

A survey conducted in 1946 and another in 1951 showed that 27 of these municipalities obtained their water supply from ground-water sources, 4 derived supplies from relatively small reservoirs on tributary streams, 2 pumped directly from the unregulated flow of the Washita River, and 2 used both underground sources and surface water stored in tributary reservoirs. The report on the Washita River Basin issued by the National Resources Planning Board in May 1943 outlined the basin`s water resources rather than the specific project work necessary for developing those resources. The report indicated that an extensive system of multiple-purpose reservoirs was the basic form of improvement required to provide for existing and prospective needs for flood control, irrigation, municipal and industrial water supply, and to afford important benefits in the form of sediment control, recreation, and fish and wildlife conservation. The report specifically recommended construction of a multiple purpose reservoir at the Foss site. The Bureau of Reclamation began investigations in 1945 to establish a plan for further development of the land and water resources consistent with the basin problems and needs.


The project was authorized by Public Law 419, 84th Congress, 2d session, approved February 25, 1956 (70 Stat. 28).


Foss Dam was constructed during 1958-1961, and Fort Cobb Dam was built in 1958-1959.

The Foss Aqueduct was constructed during 1960-1962 and the Anadarko Aqueduct was constructed during 1959-1961.

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Municipal and Industrial

Seven Oklahoma towns receive a municipal and industrial water supply as a result of the Washita Basin Project. Additionally, water is furnished to Western Farmers Electric Cooperative, and to carpet mills which have been established near Anadarko.

The original project cities in the Foss Division of the Washita Basin Project, through cooperative efforts with the Foss Reservoir Master Conservancy District, have constructed a central water treatment plant at Foss Reservoir. The treated water supply is conveyed through the project aqueduct system to each of the cities.

The Fort Cobb Division of Washita Basin Project delivers municipal and industrial water to the city of Anadarko, and to the Western Farmers Electric Cooperative, from Fort Cobb Reservoir through the project constructed Anadarko Aqueduct.


Fort Cobb Reservoir provides over 2,000 acres of land and some 2,300 acres of water surface areas for recreation and includes 1,800 acres of land and 1,800 acres of water surface area for wildlife management. This reservoir provides some 45 miles of shoreline at top of conservation pool. The recreation areas are administered by the Oklahoma Tourism and Recreation Department and the wildlife management area is administered by the Oklahoma Department of Wildlife Conservation. Since reservoir releases are primarily for municipal and industrial demands and flood control, the reservoir does not normally experience drastic drawdowns.

Foss Reservoir provides over 1,500 acres of land and over 5,000 acres of water surface for recreation purposes and some 4,500 acres of land and over 3,700 acres of water surface in the Washita National Wildlife Refuge for wildlife management. Foss Reservoir provides some 63 miles of shoreline at top of conservation pool elevation. The recreation areas are administered by the Oklahoma Tourism and Recreation Department. The Washita National Wildlife Refuge in the upper reaches of the reservoir is administered by the U.S. Fish and Wildlife Service.

Recreation at Fort Cobb and Foss Reservoirs includes sightseeing, picnicking, camping, swimming, boating, fishing, hunting, golfing, and water skiing. The State of Oklahoma has established State parks at both reservoirs, enhancing the opportunities for the public to enjoy these outdoor water-oriented activities and scenic areas.

For specific information about any of these recreation sites, click on the name below.

Foss Reservoir
Fort Cobb Reservoir
Washita National Wildlife Refuge

Flood Control

The Washita River Basin is long and narrow. The river flows generally from northwest to a southeast, perpendicular to the axis of the major frontal storms. This basin shape and orientation results in the generation of damaging floodflows. It is not unusual for several consecutive flood crests to follow within comparatively short periods.

Operations at Foss and Fort Cobb Reservoirs provide continuing flood control benefits to downstream areas previously subjected to floodflows and in resulting loss of life and damage to land areas and improvements. Flood control operations require close coordination among the master conservancy districts, the Corps of Engineers, and the Bureau of Reclamation. These reservoirs have been operated for flood control since the initial filling of the conservation pools.

The Washita Basin Project has provided an accumulated $11,572,000 in flood control benefits from 1950 to 1999.

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Last updated: Apr 05, 2013