Banks Lake

Banks Lake is a large reservoir situated in the Grand Coulee of Grant County, Washington. It serves as the equalizing reservoir for the Columbia Basin Project, one of the largest irrigation undertakings in North America. The lake was created by the construction of Dry Falls Dam and North Dam, which impound waters pumped from the Columbia River at Grand Coulee Dam. It is a central feature for water storage, recreation, and regional ecology within the Channeled Scablands.

Geography and Hydrology

Banks Lake occupies a portion of the upper Grand Coulee, a massive canyon formed by cataclysmic Missoula Floods during the Pleistocene epoch. The reservoir stretches approximately 27 miles (43 km) from Coulee City in the south to near Electric City in the north. Its primary inflow is water pumped from Franklin D. Roosevelt Lake, the reservoir behind Grand Coulee Dam, via the Feeder Canal at the Bacon Siphon. The lake's outflow is regulated at Dry Falls Dam, from which water is released into the lower Grand Coulee and subsequently into the project's vast network of canals, including the Main Canal and the Potholes Canal. The surrounding landscape is characterized by steep basalt cliffs and arid shrub-steppe, part of the broader Columbia Plateau.

History and Construction

The creation of Banks Lake was an integral component of the Columbia Basin Project, authorized by the United States Congress through the River and Harbor Act of 1945. Construction on the two earthfill dams, Dry Falls Dam and North Dam, began in the late 1940s. The reservoir was named for Frank A. Banks, the construction engineer in charge of building Grand Coulee Dam. Initial filling commenced in 1951, with the project reaching full operational capacity later in the decade. The lake's purpose was to store the immense volumes of water pumped from the Columbia River, allowing for regulated delivery to over 670,000 acres of farmland across central Washington. This transformation enabled the agricultural development of regions such as the Quincy Basin and the Royal Slope.

Ecology and Wildlife

The introduction of a permanent water body into the arid Grand Coulee significantly altered the local ecosystem. Banks Lake supports a variety of fish species, including stocked rainbow trout, walleye, smallmouth bass, and yellow perch. It is a popular destination for sport fishing and is managed by the Washington Department of Fish and Wildlife. The reservoir and its shoreline provide habitat for numerous waterfowl species, particularly during migration along the Pacific Flyway. Bald eagles and osprey are common avian predators. The surrounding shrub-steppe environment supports species like mule deer, coyotes, and various reptiles. Invasive species, such as Eurasian watermilfoil, present ongoing management challenges for preserving native habitats.

Recreation and Tourism

Banks Lake is a major hub for outdoor recreation within the Sun Lakes-Dry Falls State Park region. Popular activities include boating, water skiing, camping, and hiking. The lake features several public access points, marinas, and resorts, notably at Steamboat Rock State Park, which is dominated by a prominent butte rising from the water's edge. The area's unique geology, including proximity to the dramatic Dry Falls cataract, attracts visitors interested in natural history. Annual events like fishing derbies and regattas are held on the reservoir. The nearby Coulee Dam National Recreation Area and the Lake Roosevelt National Recreation Area further enhance the region's appeal for tourism.

Management and Water Use

Banks Lake is operated by the United States Bureau of Reclamation as a key component of the Columbia Basin Project. Its primary function is to store up to 1.275 million acre-feet of water for irrigation, supplying the project's vast network that includes the West Canal and East Low Canal. Water management is coordinated with operations at Grand Coulee Dam and other reservoirs like Potholes Reservoir to meet agricultural, municipal, and instream flow commitments. The Columbia Basin Project Hydrologic Model is used for planning and allocation. Management also involves coordination with state agencies, local irrigation districts such as the East Columbia Basin Irrigation District, and tribal nations, including the Confederated Tribes of the Colville Reservation, regarding water rights and fishery impacts.