O'Sullivan Dam (National ID # WA00268), one of the largest earthfill

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

s in the United States (200 ft/61 m high; 19,000 ft/5,791 m long; completed 1949), is on

Crab Creek Crab Creek is a stream in the U.S. state of Washington. Named for the presence of crayfish, it is one of the few perennial streams in the Columbia Basin of central Washington, flowing from the northeastern Columbia River Plateau, roughly east o ...

in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, about 45 km south of

Ephrata Ephrata may refer to: Places * Ephrata, Suriname * Ephrata, Pennsylvania, U.S. *Ephrata, Washington, U.S. * Ephrata Township, Pennsylvania, U.S. Other uses *Ephrata Cloister, a religious community in Ephrata, Pennsylvania See also * * Efrata or E ...

and 25 km south of

Moses Lake Moses Lake is a lake and reservoir along the course of Crab Creek, in Washington state, USA. Moses Lake is part of the Columbia River basin, as Crab Creek is a tributary of the Columbia River. Although originally a shallow natural lake, Moses ...

. The

Potholes Reservoir The Potholes Reservoir is part of the Columbia Basin Irrigation Project. It is formed by the O'Sullivan Dam and located in central Washington, in the United States. The reservoir is fed by water from Moses Lake, part of the Crab Creek basin. T ...

formed by this dam collects return flows from all

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...

in the upper portion of the project for reuse in the southern portion. A system of wasteways has been built on both the West and East Low Canals to provide operational safety for the

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow un ...

s and a means of delivering water into Potholes Reservoir to supplement the natural and return flow

The dam was built as part of the

Columbia Basin Project The Columbia Basin Project (or CBP) in Central Washington, United States, is the irrigation network that the Grand Coulee Dam makes possible. It is the largest water reclamation project in the United States, supplying irrigation water to over of ...

Statistics

*Active storage capacity: *Structural height of dam: 200.0 ft (60 m) *Construction date: 1947-1949 *Normal water surface elevation: 1052.0 ft (320.6 m) *

Drainage area A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

: 3,920.0 sq mi (10,153 km²) *Storm duration: 72 hr

External links

O'Sullivan Dam
* {{coord, 46, 58, 57, N, 119, 17, 28, W, display=title Dams in Washington (state) Buildings and structures in Grant County, Washington Dams completed in 1949 United States Bureau of Reclamation dams