Water pressure cause of Wanapum Dam crack

BEVERLY - The Grant County PUD said that tension from water pressure caused the 65-foot crack in the Wanapum Dam spillway. The crack was not caused by seismic activity, foundation settlement, operation of the spillway gates, or activity at the U.S. Army Yakima Training Center, according to a release from the utility.

Residents who live around the Wanapum Dam area had complained about louder than normal artillery shelling at the nearby Yakima Training Center recently. Some residents immediately pointed to that activity as a possible cause of the crack, but PUD engineers say that is not the case.

The release stated that the PUD will keep water levels at their current lowered levels at least until June. Utility district officials said the dam will be able to handle spring runoff water with cooperation from other dams on the Columbia River.

Alterations to the fish ladder at Wanapum should be completed by April 15, and PUD staff will trap salmon and truck them around the dam until the repairs are complete.

The shoreline, boat ramps and recreation facilities on Wanapum Reservoir remain closed until the PUD repairs the dam and raises water levels.