Roza Dam

Roza Dam
Name	Roza Dam
Location	Yakima County, Washington, United States
Coordinates	46°39′N 120°12′W
Operator	Bureau of Reclamation / Roza Irrigation District
Dam type	Concrete gravity diversion dam
River	Yakima River
Length	975 ft
Height	62 ft
Opening	1939
Reservoir	Roza Canal intake / diversion pool

Roza Dam

Introduction

Roza Dam is a concrete diversion dam on the Yakima River in Yakima County, Washington, United States, situated near the city of Selah, Washington and downstream of Cle Elum Lake and Satus Pass. The facility functions as a water diversion and hydro-irrigation structure integral to the Yakima Project overseen by the United States Bureau of Reclamation in coordination with the Roza Irrigation District, providing irrigation for agricultural regions including Yakima Valley orchards and vineyards that supply markets such as Seattle and Portland, Oregon. The site is connected to broader water infrastructure networks including the Yakima River Basin Water Enhancement Project and regional transport corridors like Interstate 82.

History and Construction

Construction of the dam was carried out during the late 1930s as part of federal reclamation efforts tied to New Deal–era programs associated with the Public Works Administration and the Reclamation Act of 1902 framework, reflecting national priorities exemplified by projects like Grand Coulee Dam and Bonneville Dam. Engineering planning involved the United States Bureau of Reclamation and contractors experienced from works on the Columbia Basin Project. The dam was completed and placed into operation in 1939, during a period when irrigation districts such as the Roza Irrigation District formed cooperative agreements similar to those at Kittitas County and Yakima County to allocate water rights under state statutes and interstate compacts like the Columbia River Compact. The facility’s history intersects with regional developments including the expansion of Washington State Route 823 and agricultural mechanization trends influenced by institutions such as Washington State University.

Design and Specifications

Roza Dam is a low-profile concrete gravity diversion structure with a crest length of approximately 975 feet and a structural height near 62 feet. The dam forms a diversion pool that feeds the concrete-lined Roza Canal and associated gated control works; this hydraulic configuration echoes design principles used in other Reclamation projects including Minidoka Dam and Moses Lake. Hydraulic components include radial gates, headworks, and fish passage adaptations influenced by standards promulgated by the National Marine Fisheries Service and engineering guidance from American Society of Civil Engineers practices. The facility’s mechanical systems, including gates and turbines where present for minimal power recovery, were retrofitted periodically following recommendations from U.S. Army Corps of Engineers inspections and state-level agencies such as the Washington State Department of Ecology.

Operations and Water Management

Operational control of the dam involves coordination between the Bureau of Reclamation and the Roza Irrigation District to manage diversions to the Roza Canal for irrigation deliveries to orchards, vineyards, and hop farms across the Yakima Valley AVA and surrounding tracts. Water allocation follows compacts and adjudications similar to cases overseen by the Washington State Department of Ecology and influenced by rulings in regional water litigation like Hirst v. Whatcom County that shape consumptive use policy. Seasonal operations align with snowmelt patterns in the Cascade Range and inflow forecasts from the United States Geological Survey and National Weather Service, with storage coordination among upstream facilities including Bumping Lake and Cle Elum Lake. Collaboration with fishery managers such as the Washington Department of Fish and Wildlife and tribal authorities from the Yakama Nation addresses instream flow requirements and hatchery mitigation programs like those run by the Columbia River Inter-Tribal Fish Commission.

Environmental and Ecological Impact

The dam’s diversion operations have influenced anadromous fish migrations of species such as Chinook salmon, Coho salmon, and steelhead trout, prompting mitigation measures including fish screens, passage improvements, and habitat restoration efforts coordinated with agencies like the National Marine Fisheries Service and the U.S. Fish and Wildlife Service. Environmental reviews have referenced statutes and policies from the Endangered Species Act and the National Environmental Policy Act, linking Roza Dam management to regional conservation programs such as the Yakima Basin Integrated Plan. Impacts on riparian ecosystems and sediment transport have been subject to studies by institutions including University of Washington and Washington State University, and restoration partnerships have involved entities like the Bonneville Power Administration and local conservation districts to address issues similar to those at Toppenish Creek and Ahtanum Creek.

Recreation and Local Economy

The diversion pool and adjacent river corridors support recreational activities including angling, birdwatching, and boating that attract visitors to the Yakima Valley and contribute to regional tourism marketed alongside wineries in the Columbia Valley AVA and cultural sites tied to the Yakama Nation. Agricultural productivity enabled by irrigation from the Roza Canal underpins economic clusters in fruit production, hop cultivation for breweries such as those in Yakima and Wenatchee, Washington, and freight movements through nodes like the Port of Pasco. Local agencies and stakeholders including the Yakima County planning offices coordinate land use and public access planning, integrating recreational amenities with water management priorities similar to approaches used at Rimrock Lake and other regional reservoirs.

Category:Dams in Washington (state) Category:United States Bureau of Reclamation dams