thumb|200px|Pacific Northwest River System

Wanapum Dam is a run-of-the-river 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 1,185 megawatts and annually generates over 4 million megawatt-hours.

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

Spillway crack

On February 27, 2014, a wide crack was discovered by inspection divers on one of the tall concrete monoliths that make up the spillway of the dam. A spokesman for the Grant County PUD indicated that the level of the water was to be lowered by over a period of days to "reduce the pressure on the spillway while inspectors investigate".

During the time that the water level was lowered for repairs, all beaches and water access in the area above the dam were closed to protect sensitive cultural resources and help to ensure public safety. Public access was restored in the spring of 2015.

After an 11-week inspection, the primary reason for the crack was determined to be a mathematical error during the pre-construction design of the dam. Repairs of the cracked monolith and the strengthening of the remaining monoliths were made in 2014-2015. The $61 million fix used steel cabling and rods to stitch the dam to the bedrock underneath.

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|thumb|[[Columbia River Basalt Group|Basalt bluff over the Columbia River near Wanapum Dam]]

|thumb|[[Vantage Bridge crossing Wanapum Lake]]

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See also

  • List of dams in the Columbia River watershed
  • Sensor fish, a device used to study the impact of fish travelling through the Wanapum and other dams

References

  • Biological Assessment of the Advanced Turbine Design at Wanapum Dam, 2005, Pacific Northwest National Laboratory - a study of the impact of the dam on fish