Lake Wallula

Lake Wallula
Name	Lake Wallula
Type	Reservoir
Inflow	Columbia River
Outflow	Columbia River
Basin countries	United States
Length	63mi
Area	29700acre
Formed	1954
Max-depth	140ft
Coordinates	46°16′N 118°55′W

Lake Wallula is a reservoir on the Columbia River created by the construction of McNary Dam between Umatilla County, Oregon and Benton County, Washington. The impoundment lies upstream of John Day Dam and downstream of Bonneville Dam within the Columbia River Basin, providing hydroelectric power, navigation, irrigated agriculture, and recreation. The reservoir and associated facilities intersect with Umatilla Indian Reservation, Confederated Tribes of the Umatilla Indian Reservation, Hanford Site proximities, and regional transportation corridors such as Interstate 82 and U.S. Route 730.

Geography and hydrology

Lake Wallula extends approximately 63 miles from the McNary Dam to near the mouth of the Snake River, impounding water across sections of Washington (state) and Oregon. The reservoir occupies parts of Benton County, Washington, Walla Walla County, Washington, Umatilla County, Oregon, and fringes of Morrow County, Oregon. Major tributaries include the Umatilla River, Walla Walla River, and John Day River via the Columbia, and the reservoir impacts flow regimes into the Snake River system and the broader Pacific Northwest hydrologic network. Seasonal variation is influenced by snowpack in the Cascade Range, Blue Mountains, and Columbia Plateau, as monitored by agencies such as the United States Geological Survey and the National Oceanic and Atmospheric Administration.

The reservoir altered sediment transport, thermal stratification, and dissolved oxygen profiles relative to pre-dam conditions documented by the U.S. Bureau of Reclamation and the U.S. Army Corps of Engineers. Flow regulation for flood control, navigation, and Bonneville Power Administration-managed power schedules affects downstream facilities including The Dalles Dam and John Day Dam. Water elevation and release patterns are coordinated under compacts involving the State of Oregon, State of Washington, and federal entities such as the Environmental Protection Agency.

History and construction

Planning for the project that created the reservoir emerged from New Deal-era and post-war river development policies championed by agencies like the U.S. Army Corps of Engineers and the Tennessee Valley Authority-influenced approach to multipurpose dams. Authorization for McNary Dam followed legislative actions in the mid-20th century and was executed during the Dwight D. Eisenhower administration with construction overseen by federal contractors and engineers trained at institutions such as the Massachusetts Institute of Technology and Stanford University.

The impoundment began filling after completion of McNary Dam in 1954, inundating riverine habitats, low-lying settlements, and transportation links documented in contemporaneous reports by the U.S. Bureau of Reclamation and regional newspapers like the Oregonian. The project intersected with treaties and land claims involving the Treaty of 1855 (Walla Walla Treaty), litigation involving the Confederated Tribes of the Umatilla Indian Reservation, and consultation frameworks later shaped by the National Environmental Policy Act and rulings from the United States Court of Appeals for the Ninth Circuit.

Ecology and wildlife

The reservoir and riparian zones support populations of anadromous and resident fish including Chinook salmon, Coho salmon, Steelhead trout, Rainbow trout, and Smallmouth bass subject to mitigation measures such as fish ladders at McNary Dam and hatchery programs administered by the National Marine Fisheries Service and state agencies like the Washington Department of Fish and Wildlife and the Oregon Department of Fish and Wildlife. Species distribution has been influenced by the Endangered Species Act listings of certain salmonid populations and recovery plans developed in coordination with the Bonneville Power Administration.

Shoreline habitats include riparian corridors with species such as cottonwood stands and shrub-steppe communities that provide nesting and foraging for birds like bald eagle, great blue heron, western meadowlark, and migratory species on the Pacific Flyway. Aquatic invasive species concerns include zebra mussel monitoring and coordinated responses by the U.S. Fish and Wildlife Service and state invasive species councils. Research and monitoring have been conducted by institutions including Oregon State University, Washington State University, and federal laboratories such as Pacific Northwest National Laboratory.

Recreation and public use

Lake Wallula is a regional recreation resource offering boating, angling, waterfowl hunting, and shoreline camping managed through public lands administered by the U.S. Army Corps of Engineers and state parks such as McNary National Wildlife Refuge adjacency and nearby sites like Juniper Canyon and local marina facilities serving Umatilla and Hermiston, Oregon. Anglers pursue species managed under harvest regulations from the Pacific Fishery Management Council and state fish and wildlife agencies, while boating access is provided at ramps near Pine City, Washington and Umatilla, Oregon.

Public safety, navigation aids, and search-and-rescue involve coordination with entities like the United States Coast Guard Auxiliary-adjacent volunteers, Benton County Sheriff's Office, and local fire districts. Tourism and heritage interpretation often highlight connections to the Lewis and Clark Expedition, regional rail history involving Union Pacific Railroad, and local agricultural communities including irrigation districts that rely on reservoir storage.

Water management and infrastructure

Operation of the reservoir is integral to the Columbia River Treaty-influenced basin operations, hydroelectric generation managed by the Bonneville Power Administration, and navigation support for barge traffic linking inland terminals to the Port of Portland and Port of Pasco. Infrastructure includes the McNary Dam powerhouse, spillways, navigation locks, and associated transmission lines that feed regional grids coordinated via entities like the North American Electric Reliability Corporation.

Water allocation intersects with irrigation projects serving growers of wheat and hay on the Columbia Plateau, as administered by local irrigation districts and subject to interstate compacts adjudicated through courts including the United States Supreme Court in watershed disputes. Environmental mitigation infrastructure such as fish bypass systems, monitoring stations by the U.S. Geological Survey, and habitat restoration projects funded by agencies including the Environmental Protection Agency and non-governmental organizations like the Nature Conservancy continue to shape operations.

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