Rimrock Lake is a lake along the course of the

Tieton River The Tieton River is a tributary of the Naches River, in Yakima County, Washington in the United States. The Tieton River begins in two forks, the North Fork Tieton River and South Fork Tieton River. The North Fork originates at McCall Glacier on ...

, in

Yakima County Yakima County is a county in the U.S. state of Washington. As of the 2020 census, its population was 256,728. The county seat and largest city is Yakima. The county was formed out of Ferguson County in January 1865 and is named for the Yakam ...

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 ...

state, US. The lake is used as a storage

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

for the Yakima Project, an irrigation project run by the

United States Bureau of Reclamation The Bureau of Reclamation, and formerly the United States Reclamation Service, is a federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it applies to the oversight and opera ...

. An impoundment of the Tieton River, Rimrock Lake's capacity and discharge is controlled by

Tieton Dam Tieton Dam is an earth and concrete type dam on the Tieton River in Yakima County, in the U.S. state of Washington. The dam began operation in 1925. Its reservoir, Rimrock Lake, has a total capacity of with a normal operating capacity of to prov ...

, a 319-foot (97 m) high structure built in 1925. Rimrock Lake's active capacity is .Yakima Project

. Upstream from the lake, the Tieton River is impounded by Clear Creek Dam, another element of the Yakima Project. About downstream from Rimrock Lake the Tieton River is tapped by the Tieton Diversion Dam, supplying water to the Tieton Main Canal. The canal supplies irrigation water to the Tieton Division of the Yakima Project, with excess and agricultural runoff draining into

Ahtanum Creek Ahtanum Creek is a tributary of the Yakima River in the U.S. state of Washington. It starts at the confluence of the Middle and North Forks of Ahtanum Creek near Tampico, flows along the north base of Ahtanum Ridge, ends at the Yakima River near ...

, west of

Yakima Yakima ( or ) is a city in and the county seat of Yakima County, Washington, and the state's 11th-largest city by population. As of the 2020 census, the city had a total population of 96,968 and a metropolitan population of 256,728. The uni ...

. Near the lakes are the communities of

Rimrock Rimrock is the sheer rock wall at the upper edge of a plateau, canyon, or geological uplift. It may refer to either the rock formation or to the rock itself. Rimrock may be composed of almost any stone—basalt, gneiss, granite, sandstone, et ...

and Silver Beach.

References

External links

* * Reservoirs in Washington (state) Lakes of Yakima County, Washington Protected areas of Yakima County, Washington Mount Baker-Snoqualmie National Forest Tributaries of the Yakima River {{YakimaCountyWA-geo-stub