Leaks spur officials to lower water levels behind Priest Rapids Dam
Grant Public Utility District officials are reducing water levels behind the Priest Rapids Dam on the Columbia River after an inspection revealed leaks.
There is no threat to life of property, the PUD said in a news release.
The PUD declared a “non-failure emergency” after an inspection revealed leaking in spillway monoliths, which are the expanse of concrete below each of the 40 foot by 50 foot spillways. Priest Rapids is near Mattawa.
The dam has 22 spillways.
The PUD said the dam will continue to general electricity.
The reservoir behind the dam will be held between 481 feet to 484 feet above sea level, within the lower end of the normal operating range.
A contract crew drilling inspection holes discovered the leaking.
The situation is different from a 2014 incident at Wanapum Dam that required a prolonged drawdown.
Crews will drill more inspection holes from an internal passageway in Priest Rapids called “the grout gallery.” The gallery runs the length of the spillway.
When the drilling is complete, the PUD will devise a repair strategy, if necessary.
The investigation and drilling at Priest Rapids is is considered precautionary.
Wendy Culverwell: 509-582-1514, @WendyCulverwell
This story was originally published March 28, 2018 at 6:52 PM with the headline "Leaks spur officials to lower water levels behind Priest Rapids Dam."