By Justin Brimer
Herald staff writer
MATTAWA — Boaters were evacuated over the weekend near Wanapum Dam because of a 65-foot crack in the Wanapum Dam spillway.The district is also lowering water levels by about 20 feet and expects to reach this goal by Monday.
All boat launches at the Wanapum and Priest Rapids reservoirs are closed.
District spokesman Thomas Stredwick said to his knowledge this large of a crack has never been found on a Grant PUD dam. The district is notifying property owners on the Columbia River as part of its emergency action plan.
He said engineers noticed something unusual on the water level while doing routine inspections at the dam earlier in the week. After sending divers into the water, they learned that the crack, which spans the entire length of the dam, had formed about 70 feet under water.
Stredwick said the dam could potentially fail, but that PUD engineers do not foresee that happening.
He said it was unclear how the crack formed, and engineers are onsite to monitor the dam.
Water levels have been reduced by 20 feet to alleviate some of the pressure on the dam, and the site continues to produce electricity. Other dams down river have been notified, as they will have to deal with the extra water that the PUD releases.
For updates on this story, read Monday’s edition of the Columbia Basin Herald.