Wanapum Dam

Wanapum Dam
Dam viewed from downstream on the west bank
Official name	Wanapum Dam
Location	Grant / Kittitas counties, Washington
Coordinates	46°52′31″N 119°58′16″W
Construction began	1959
Opening date	1963
Construction cost	$195,000,000
Dam and spillways
Impounds	Columbia River
Reservoir
Creates	Lake Wanapum
Capacity	796,000 acre·ft (0.982 km3)
Power station
Installed capacity	1,038 MW

Basalt bluff over the Columbia River near Wanapum Dam

Wanapum Dam is a hydroelectric project located on the Columbia River downstream (south) from Vantage, Washington where Interstate 90 crosses the Columbia from Grant County into Kittitas County. It is owned by the Grant County Public Utility District. Its reservoir is named Lake Wanapum.

The dam, and its lake, are named after the Wanapum Indians. The dam has a rated capacity of 1,038 megawatts and annually generates over 4 million megawatt-hours.

History

The Wanapum dam was originally licensed in 1955 for a period of 50 years. Construction was initiated in 1959 with initial beneficial operation in 1963. The initial license expired in 2005, after which the Grant County PUD operated the dam on yearly license extensions while negotiations for license extension proceeded. The Federal Energy Regulatory Commission approved a license extension of 44 years for both the Wanapum dam and the downstream Priest Rapids dam on April 17, 2008. The license extension was conditioned upon programs to:

• modernize the power generation capability of the dam,
• monitor water quality,
• improve wildlife habitat,
• protect nearly 700 Wanapum Tribe archaeological sites in the vicinity, and
• enhance recreation with new campsites, picnic areas and trails.

Vantage Bridge crossing Wanapum Lake