Bureau of Reclamation Banner
Belle Fourche Project
Photo of Belle Fourche Dam and Reservoir
Project Links
Project History
Project Data
Contact Information
Related Facilities
Related Documents
Belle Fourche Project History - 261 KB (pdf)
General Description| Plan| Development| Benefits


General Description

Belle Fourche Project is located in western South Dakota northeast of the Black Hills. Principal structures include a diversion dam, a storage dam, and a system of canals, laterals, and drains to irrigate 57,068 acres in the general area of Newell, Vale, and Nisland, South Dakota, along the valley of the Belle Fourche River. The project is a single-purpose development; however, flood control, fish and wildlife conservation, and recreation benefits are inherently provided.

Return to top


Water for irrigation is diverted from the Belle Fourche River and conveyed by means of Inlet Canal to Belle Fourche Reservoir for regulatory storage and for delivery to project lands. The Keyhole Unit of the Pick-Sloan Missouri Basin Program, consisting of Keyhole Dam and Reservoir on the Belle Fourche River in northeastern Wyoming, provides supplemental storage and a supply of irrigation water.

Facility Descriptions

The Belle Fourche Diversion Dam is on the Belle Fourche River about 1.5 miles northeast of the city of Belle Fourche, South Dakota. It has a concrete ogee weir 400 feet long, a structural height of 36 feet, and a 2,100-foot-long earth embankment on the right abutment.

Inlet Canal

The 6.3-mile Inlet Canal, with a capacity of 1,300 cubic feet per second, conveys water from the Belle Fourche Diversion Dam to off-channel regulatory reservoir storage in Belle Fourche Reservoir on Owl Creek behind the Belle Fourche Dam.

Belle Fourche Dam (formerly Orman Dam), located about 10 miles northeast of Belle Fourche, is a homogeneous earthfill structure 6,262 feet long and 122 feet high. It was constructed across Owl Creek, an intermittent stream tributary to the Belle Fourche River. The act of October 27, 1974 (88 Stat. 1486), authorized modification of Belle Fourche Dam to include a new spillway and improvement of the upstream slope protection of the dam to ensure safety. The work was started during 1976 and completed in 1977.

The new earth-lined spillway has a discharge capacity of 4,500 cubic feet per second. It is located approximately 1 mile south of the right abutment of the dam.

The controlled outlet works consist of two horseshoe-shaped conduits through the base of the dam, one each for the North and South Canals, with capacities of 600 and 300 cubic feet per second, respectively.

The dam forms Belle Fourche Reservoir which has an active conservation capacity of 185,200 acre-feet, and a water surface area of 8,000 acres. Dead storage is 6,800 acre-feet.

Supply, Distribution, and Drainage System

Supply, distribution, and drainage systems serving the irrigated lands consist of 94 miles of irrigation canals, 450 miles of irrigation laterals, and 232 miles of drains, including 7 miles of closed (pipe) drains.

Belle Fourche River Compact

A compact between the States of Wyoming and South Dakota, confirmed by the Congress of the United States in 1944, provides for the apportionment of Belle Fourche River waters upstream from the Wyoming-South Dakota boundary. This compact provides that the unappropriated flow of the Belle Fourche River shall be apportioned 10 percent to Wyoming and 90 percent to South Dakota, provided that Wyoming shall have unrestricted use of the water for domestic and stock purposes. The apportioned flow to South Dakota is the principal irrigation water source for the Belle Fourche Project.

Return to top



Belle Fourche, the name of the principal project town, means `Beautiful Forks` in French. The name has reference to the confluence of the Redwater and Belle Fourche Rivers. Frenchmen settled in this vicinity and reportedly engaged in fur trading with the Indians as early as 1854. The gold rush to the Black Hills in 1876 brought many people to the general area.

In the early days, raising livestock was the principal industry in the vicinity of the project. The Chicago and Northwestern Railway reached the town of Belle Fourche in 1891 and for the remainder of the century the town was considered to be the largest original shipping point for livestock in the United States.


A survey of the Belle Fourche Project area for irrigation potential was initiated by the Reclamation Service in July 1903.


The Secretary of the Interior authorized construction of the Belle Fourche Project on May 10, 1904, on the basis of the findings of the survey started in 1903.


Construction of the facilities for the Belle Fourche Project began in 1905 and had progressed sufficiently by 1908 to permit the delivery of irrigation water to 12,000 acres. The original project was completed in 1914. Some of the scheduled extensions of the original project were not constructed because of inadequate water supplies and adverse economic conditions.

Rehabilitation and Betterment

Rehabilitation and betterment construction was accomplished from 1950 to 1953. It consisted of replacement of the valves in outlet works of the dam, replacement of major structures in canals and laterals, and improvement of the drainage system.

Return to top



A full supply of irrigation water is provided to 57,068 acres of irrigable land. The principal irrigated crops grown on the project are alfalfa and corn. Other crops include barley, oats, and forage. Irrigated lands are dispersed throughout the project area and most farm units include both irrigated and dry-farmed lands.


The primary recreation activity at Belle Fourche Reservoir is fishing, with limited boating and water skiing. Access roads, sanitary facilities, and boat ramp developments around the reservoir area and the reservoir fisheries are operated and maintained by the South Dakota Department of Wildlife, Parks and Forestry.

For specific information about recreational opportunities at Belle Fourche Reservoir click on the name below.

Belle Fourche Reservoir 
Flood Control

Belle Fourche Reservoir has no capacity allocated exclusively to flood storage; however, a surcharge capacity of 86,139 acre-feet allows minimal flood control benefits inherent in the overall operation of the reservoir by the impounding of floodflows in Owl Creek and diverting water from Belle Fourche River as needed for the conservation storage.

Return to top

Last updated: Apr 04, 2013