In Central Washington, Grant Public Utility District officials have declared what they’re calling a “non-failure emergency” at the 1950’s-era Priest Rapids Dam northwest of Richland.
Crews discovered leaking in the dam’s spillway structure when they were drilling inspection holes.
“There was more water flowing through than we’d normally expect,” said Chuck Allen, a spokesman for Grant PUD.
Officials have lowered the pool behind the dam to a level that is about 2 to 3 feet below normal for this time of year. That’s to lessen the pressure on the dam while they do more inspections.
Priest Rapids is the last dam upriver from the Hanford nuclear cleanup site and the dramatic natural area called the Hanford Reach National Monument.
The dam holds back a pool on the Columbia River that stretches more than 18 miles.
This is the second time Grant PUD has had to deal with an emergency at one of its dams.
Back in 2014, a massive crack was discovered in the base of the spillway at Wanapum Dam, which was never tethered properly to bedrock. That required its reservoir to be drawn down for months for repairs — fouling summer recreational docks, fish passage systems and even uncovering Native American burial sites.
At Priest Rapids Dam, officials think they have leaking monoliths — the concrete buttress structures that hold up the spillway gates. The dam has 22 of them.
Officials said they are declaring the emergency “out of an abundance of caution.” Dam operations and power production will continue as normal.