Dry Falls Dam is a rockfaced earthfill type
, Bureau of Reclamation

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 ...

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 sove ...

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 ...

. Located in

Grant County Grant County may refer to: Places ;Australia * County of Grant, Victoria ;United States *Grant County, Arkansas *Grant County, Indiana * Grant County, Kansas *Grant County, Kentucky *Grant County, Minnesota *Grant County, Nebraska *Grant C ...

near

Coulee City Coulee City is a town in Grant County, Washington. The population was 549 at the 2020 census. History The town was named after nearby Grand Coulee. Coulee City was officially incorporated on May 10, 1907. Geography Coulee City is located at ...

, it was built as part of the Bureau of Reclamation's

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 ...

. Water from the Columbia River, impounded by

Grand Coulee Dam Grand Coulee Dam is a concrete gravity dam on the Columbia River in the U.S. state of Washington, built to produce hydroelectric power and provide irrigation water. Constructed between 1933 and 1942, Grand Coulee originally had two powerh ...

, is pumped into

Grand Coulee Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about 60 miles (100 km) southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower ...

, a formerly dry canyon, through the short Feeder Canal. Grand Coulee's north end is sealed by

North Dam North Dam is an earth-fill embankment dam near the town of Grand Coulee in Grant County, Washington, United States. Construction of the dam began in 1946 and it was completed in 1951. Along with Dry Falls Dam about to the southeast, North Dam cr ...

and Dry Falls Dam stretches across the midsection of the Coulee. This allows the water pumped from the Columbia River to fill the upper Grand Coulee, creating a large equalizing reservoir known as

Banks Lake Banks Lake is a long reservoir in central Washington in the United States. Part of the Columbia Basin Project, Banks Lake occupies the northern portion of the Grand Coulee, a formerly dry coulee near the Columbia River, formed by the Missoula Fl ...

. Water from the reservoir is fed into the irrigation project's Main Canal, which runs south from Dry Falls Dam to another reservoir called

Billy Clapp Lake Billy may refer to: * Billy (name), a name (and list of people with the name) Animals * Billy (dog), a dog breed * Billy (pigeon), awarded the Dickin Medal in 1945 * Billy (pygmy hippo), a pet of U.S. President Calvin Coolidge * Billy, a young ...

, formed by

Pinto Dam Pinto Dam is a dam in Grant County, Washington. The dam was a project of the United States Bureau of Reclamation, completed from 1946 through 1948 as one element of the vast Columbia Basin Project for irrigation water storage, flood control, and h ...

Works

Both

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north ...

and Dry Falls Dams are rock-faced, earthfill dams. They were built to create Banks Lake, long as an equalizing reservoir, with storage capacity of 715,000 acre-feet for irrigation. The reverse flow back to the Columbia River, provides additional electrical power.https://www.usbr.gov/projects/facilities.php?region=Pacific Northwest The feeder canal from Banks Lake has a capacity of 26,000 cubic feet per second, Dry Falls Dam and the Main Canal headworks are near

. While not a part of the Dry Falls Dam, the Main Canal Headworks was expanded to add a six pump/generating units. The Main Canal was widened from to .

History

Originally known as the South Coulee Dam, Dry Falls Dam began construction in 1946. Roy L. Blair and Company and James Crick and Sons, were awarded the contract for $2,771,887 to build the dam. Work began in mid-July. Included in the contract was the dam across the

, the approach channel, the headworks and control structure, and the initial reach to the main canal. A cutoff trench was created down to bedrock along the length of the dam. A continuous concrete wall was centered in the trench with footings at least . The wall prevents seepage of water under the dam, and is from high. The construction of the canal head works began in March 1948, and was completed a year later. Designed as a zoned earth embankment structure with an impervious central core, a semi-pervious layer on either side of the core, and a layer of rock fill. The semi-pervious layer was built in layers and compacted. The rock fill laid up in layers without compaction.

References

External links

Dry Falls Dam
Bureau of Reclamation {{DEFAULTSORT:Dry Dams in Washington (state) Buildings and structures in Grant County, Washington United States Bureau of Reclamation dams Dams completed in 1949 Earth-filled dams 1949 establishments in Washington (state) Dams in the Columbia Basin