From staff reports:
The King County Council has passed legislation approving $34.6 million in funding for flood preparation activities in the Green River Valley as requested by King County Executive Kurt Triplett in September.
The original funding request was aimed at preparing King County and local cities to mitigate or avoid long-term damage that could result from flooding caused by a damaged abutment at the Howard Hanson Dam. The U.S. Army Corps of Engineers owns and operates the dam, which is located 34 miles upstream from Auburn.
In the event of heavy rains, the Army Corps may not be able to hold back as much water behind the dam, potentially causing flooding in cities downstream and flood-related impacts throughout the Green River Valley.
A total of $7.4 million of wastewater treatment funds will help maintain operations at the South Treatment Plant during a flood. The remainder will be used to plan for and take steps to keep other regional services operating in the event of a flood.
Plans for evacuating up to 30,000 residents of the Green River Valley are complete, with work under way to shelter up to 5,000 evacuees for several weeks at a time, according to officials from King County agencies who earlier this month briefed the Metropolitan King County Council’s Committee of the Whole.
Heather Kelly, program manager for the King County Office of Emergency Management, said up to 30,000 residents of the Green River Valley could be displaced by flooding, with up to 10 to 20 percent of those needing sheltering. She said local cities in the potential flood path have said they can currently shelter only about 100 people, so the County’s focus is on establishing what she called “mega-shelters” that can house up to 5,000 evacuees for extended periods.
Among the regional facilities Kelly said the County has contacted are the Qwest Field Event Center, Tacoma Dome, Washington State Convention Center, and Port of Seattle’s Cruise Passenger Terminal.
Road signs designating evacuation routes from the potential flood zone are being fabricated now and could be ready for installation by the end of the month, according to the King County Department of Transportation. The county has worked with local cities to identify about 13 potential evacuation routes along 40 miles of roads in unincorporated King County.
