Feds asked to pay to repair dam

Elected officials representing King County and cities threatened by flooding from the Green River asked the federal government Thursday for money to pay for a temporary repair of the Howard Hanson Dam.

County Executive Dow Constantine and officials of Kent, Renton, Auburn and Tukwila were on hand Thursday when the Army Corps of Engineers' Seattle District commander, Col. Anthony Wright, said his agency has a plan — but no money — to dramatically reduce the flood risk as early as next winter.

Wright said that it would cost $44 million to make a second set of interim repairs to slow the flow of water through one flank of the earthen dam on the Green River.

"I've been looking very carefully through my sock drawer, trying to find cash for this," Wright said as he paced a large roomful of officials and reporters at the Corps' district headquarters south of downtown Seattle. "You have to realize there are a lot of things happening with the government now."

The temporary repair — lengthening and deepening a grout curtain installed last year — would stop most, but not all, seepage of water through the dam's right abutment. It would have "a life span of a couple major flood events," meaning the full benefit of the work might not last until a permanent fix could be completed in 2015, Wright said.

The Corps, now studying how best to fix the dam abutment permanently, will ask Congress for funding in fiscal year 2012 for a job that hasn't been priced but that Wright said will run into the hundreds of millions of dollars.

The dam has prevented flooding for almost 50 years, but damage discovered after a January 2009 storm led the Corps to reduce its storage capacity. That means more water may be released during a major storm to guarantee the dam doesn't collapse.

If Congress were to appropriate money for the fix quickly — "which I don't consider likely," Wright said — it would take another six months to strengthen the abutment somewhat and 10 months to complete the job.

Officials at the briefing and a spokeswoman for U.S. Sen. Patty Murray said they would seek a midyear federal appropriation to bolster the dam. Tukwila Mayor Jim Haggerton, calling the Green River Valley "one of the largest economic engines in the state of Washington," said it is "really super, super important" to obtain the money.

"The clock is ticking," said Auburn Mayor Pete Lewis, warning that warehouses, factories and other businesses are being "held hostage" by the specter of floods.

Julia Patterson, who chairs both the Metropolitan King County Council and the King County Flood Control District, said the threat of flooding "has literally driven businesses" from the valley.

Alex Glass, a spokeswoman for Murray, said temporary and permanent repairs to the dam are "a top priority for her. We know that this is important for the community and the economy, and she's going to be looking at every possible way to help get this funding. It is a tough budget year and a tough lift."

The grout curtain installed last year, combined with improvements to levees downstream, reduced the likelihood of flooding from about 1-in-3 to 1-in-33, Wright said.

If the grout curtain is improved, he said the odds might be lowered to 1-in-140, the historic level.

Keith Ervin: 206-464-2105 or kervin@seattletimes.com