Cracked Columbia River dam not anchored in bedrock

BEVERLY, Wash. — Repairing Wanapum Dam will likely require anchoring the entire spillway to bedrock, not just one section where a crack was discovered, a utility official said.

The $61 million repair estimate includes the cost of installing anchors on each of the spillway’s 12 monoliths or massive concrete sections, Grant County Public Utility District chief financial officer Kevin Nordt said Tuesday.

Engineers have said when the Columbia River dam was built in the early 1960s, designers believed its mass alone would be enough to hold it in place, The Wenatchee World reported (

The reason for the 65-foot crack has not been officially determined, but officials have suggested it could have been caused by water pressure. The reservoir was lowered after the crack was discovered Feb. 27 at the dam, which is just south of the Interstate 90 bridge near Vantage.

The utility is working with federal dam authorities, state agencies, tribes and a panel of independent experts to study the damage and plan repairs.

Until a repair plan is approved, it’s uncertain how many of the anchors would be installed, Nordt said.

The anchors would run from the top of the spillway through the concrete structure and anchor in bedrock using grout, utility spokesman Chuck Allen said Tuesday. The anchors can be cinched down to hold the spillway in place.

Some drilling is already underway to gauge the size of the crack and to create holes for the anchors, Allen said.

Utility customers will pay about a third of the repair costs and the district can pay for the rest from reserves and financing without an additional rate increase, officials said.

The 26-foot drawdown of the pool behind the dam reduced its capacity to generate electricity. It also affected operation of the Chelan County Public Utility District’s Rock Island Dam, 36 miles upriver. The Rock Island pool was drawn down a few feet to protect generating equipment. Both utilities have modified their fish ladders to help migrating spring chinook and steelhead get past the dams.

More in Local News

At long last, a church of his own

After years of filling in elsewhere, Hallack Greider is the new pastor at Maplewood Presbyterian.

Judge: Lawmakers’ emails, texts subject to public disclosure

News organizations had sued to challenge the Legislature’s claim that members were exempt.

Everett’s Donna Witte at the Seattle Women’s March last year. Witte plans to join the Seattle Women’s March 2.0 on Saturday. (Courtesy Donna Witte)
Everett events part of national ‘March to Impeach’

“The main thing that draws me out is the realization I have been taking this democracy for granted.”

Outgoing councilwoman honored by Marysville Fire District

The Marysville Fire District in December honored outgoing City Councilwoman Donna Wright… Continue reading

Everett district relents on eminent domain moving expenses

Homeowners near Bothell still must be out by April to make way for a planned new high school.

Their grown children died, but state law won’t let them sue

Families are seeking a change in the state’s limiting wrongful-death law.

Officials rule train-pedestrian death an accident

The 37-year-old man was trying to move off the tracks when the train hit him, police say.

Ex-Monroe cop re-arrested after losing sex crime case appeal

He was sentenced to 14 months in prison but was free while trying to get his conviction overturned.

Marysville hit-and-run leaves man with broken bones

The state patrol has asked for help solving an increasing number of hit-and-run cases in the state.

Most Read