McNary Reservoir

McNary Reservoir
Name	McNary Reservoir
Location	Umatilla County, Benton County, Franklin County
Type	Reservoir
Inflow	Columbia River
Outflow	Columbia River
Basin countries	United States
Created	1954

McNary Reservoir is a reservoir on the Columbia River formed by the impoundment behind the McNary Dam between Oregon and Washington. The reservoir lies adjacent to Umatilla and downstream from Potholes Reservoir and upstream from John Day Dam. It serves multiple purposes including hydroelectric generation, navigation, irrigation, and fish passage within the Columbia Basin Project and the Bonneville Power Administration transmission network.

Overview

McNary Reservoir occupies a reach of the Columbia River bounded by McNary Dam and the tailwater of John Day Dam, affecting communities such as Umatilla, Kennewick, Pasco, and Hermiston. It is integrated with infrastructure administered by the U.S. Army Corps of Engineers, coordinated with operations of the Bonneville Power Administration and the Bureau of Reclamation as part of river management strategies tied to the Columbia River Treaty and the Pacific Northwest Coordination Agreement. Navigation through the reservoir is facilitated for barge traffic linked to ports like the Port of Umatilla and the Port of Pasco and supports irrigation diversions for projects connected to Yakima Project and Columbia Basin Project facilities.

History and Construction

The reservoir was formed following completion of McNary Dam in 1954, a project planned amid post-World War II infrastructure initiatives associated with agencies including the U.S. Army Corps of Engineers and the Bureau of Reclamation. Its construction reflects mid-20th century priorities such as expanded hydroelectric capacity by utilities like the Bonneville Power Administration and regional economic development influenced by federal legislation including elements of the Flood Control Act of 1944. Construction impacted Indigenous communities linked to tribes such as the Confederated Tribes of the Umatilla Indian Reservation, the Nez Perce Tribe, and the Yakama Nation, and intersected with legal frameworks including treaty rights adjudicated in cases like United States v. Winans and negotiations connected to the Boldt Decision era fisheries management.

Hydrology and Water Management

Hydrologic regime in the reservoir is governed by seasonal flows originating in tributaries such as the Snake River and regulated through the Columbia River Basin storage system encompassing projects like Grand Coulee Dam and Duncan Dam. Operations coordinate hydroelectric generation at McNary Dam with spill and bypass strategies for salmonid passage developed under mandates involving the National Marine Fisheries Service and measures informed by the Endangered Species Act. Water level management affects navigation locks used by inland shipping tied to networks reaching the Columbia-Snake River System and interlinks with the Pacific Northwest Smart Grid Demonstration Project insofar as peaking power and ancillary services are provided to entities such as Pacific Northwest National Laboratory and regional utilities including Avista Corporation.

Ecology and Wildlife

The reservoir environment supports fish populations including Chinook salmon, Sockeye salmon, steelhead, and White sturgeon, and is affected by migration patterns coordinated through fish ladders and juvenile bypass systems developed with input from agencies like the U.S. Fish and Wildlife Service and tribal biologists from the Confederated Tribes and Bands of the Yakama Nation. Shoreline habitats host waterfowl species managed in part by refuges such as Umatilla National Wildlife Refuge and support riparian vegetation similar to communities found in the Columbia River Gorge National Scenic Area. Aquatic invasive species issues parallel those at Lake Powell and Columbia River Basin sites, with monitoring by organizations like the Invasive Species Advisory Committee and state departments including the Oregon Department of Fish and Wildlife and the Washington Department of Fish and Wildlife.

Recreation and Facilities

Recreational opportunities around the reservoir include boating, sport fishing, hunting, and birdwatching, with facilities operated by local parks and marinas linked to municipal authorities such as Umatilla County parks and the City of Kennewick. Angling targets species monitored by regional hatchery programs like those coordinated with the Columbia River Inter-Tribal Fish Commission and state hatcheries in the Columbia Basin. Trails and day-use areas provide access for visitors from metropolitan centers like Tri-Cities and Pendleton, while commercial services include outfitters and charter operations registered with regional tourism bureaus and chambers such as the Greater Pasco Chamber of Commerce.

Environmental Issues and Conservation

Environmental concerns include impacts on anadromous fish passage highlighted in litigation and policy debates involving parties such as the State of Oregon and State of Washington, scientific assessments by institutions like the Northwest Power and Conservation Council, and mitigation programs funded via mechanisms used by the Bonneville Power Administration. Contaminants and legacy pollution from upstream industrial and agricultural activities intersect with studies conducted by the Environmental Protection Agency and state environmental agencies; remediation efforts coordinate with conservation NGOs including the Nature Conservancy and tribal restoration initiatives supported by entities like the Colville Confederated Tribes. Climate change projections from models at NOAA and the Intergovernmental Panel on Climate Change influence adaptive management strategies for reservoir operations, habitat restoration, and water allocation policies.

Cultural and Economic Impact

The reservoir has shaped regional commerce, transportation, and hydroelectric revenue streams affecting ports such as the Port of Umatilla and urban centers including Richland and Hermiston. It figures in cultural landscapes of Indigenous nations including the Confederated Tribes of the Umatilla Indian Reservation and in local histories preserved by museums such as the Umatilla County Historical Society. Economic activities tied to agriculture and irrigation benefit from water deliveries coordinated with projects like the Columbia Basin Project, while controversies over fishery sustainability and hydropower reflect ongoing debates involving stakeholders ranging from federal agencies to tribal governments and conservation organizations such as the Sierra Club.

Category:Reservoirs in Oregon Category:Reservoirs in Washington (state)