Water behind the Wanapum Dam near Vantage, Wash., is being drawn down 26 feet to relieve pressure on the big crack in the structure.
Officials say dozens of engineers are on site, and more around the country are studying the problem.
Water behind Wanapum Dam will soon be at levels not seen since the reservoir was filled in 1964. There will still be about 105 feet of water in the pool above the dam.
Thomas Stredwick from the Grant County Public Utility District, which operates and owns the dam, says, “Once things have stabilized there we will have a better sense of if this is a fix over a series of weeks, or is this is a fix that will take a couple of months.”
But they still don’t know what that fix will be and that’s what engineers are looking at.
Stredwick explains that with the drawdown dam operators have already seen the 65-foot crack in the dam’s spillway structure narrow about a quarter of an inch. Before, the crack had been about two inches wide.
Grant County officials are saying communities below the dams are safe. If part of the dam was to fail, river levels would not flood towns.