Plans for evacuating up to 30,000 residents of the Green River Valley are complete, with work well under way on plans for sheltering up to 5,000 evacuees for several weeks at a time, according to officials from King County agencies who briefed the Metropolitan King County Council’s Committee of the Whole on Monday. The committee has been holding hearings on preparations for the potential flood threat from the federally owned and operated Howard Hanson Dam.

Heather Kelly, Program Manager for the King County Office of Emergency Management, 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 of time.

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.

Kelly said the County is working with the Red Cross to establish and staff two mega-shelters and five smaller shelters. She said the county is also seeking to establish shelters for people with medical needs, people who need to stay close to their homes because of livestock or pets, and those who need sheltering but cannot go to a medical or Red Cross shelter.

“The consistent message we hear from flood experts is that collaboration is the key to successful flood preparations,” said Councilmember Bob Ferguson, Chair of the Committee of the Whole. “It was encouraging to hear today that effective communication and cooperation is happening here in King County as we prepare for potential Green River flooding.”

“The scenario of King County residents with nowhere to go – or worse, no way to get there is unacceptable. Evacuation and shelter planning will prevent thousands of valley citizens from being stranded,” said Councilmember Reagan Dunn. “I applaud and encourage King County agencies to continue this important flood preparation work.”

“King County agencies have put a lot of hard work into coordinated plans to prevent flooding, and to protect the residents of the Green River Valley should flooding occur,” said Council Chair Dow Constantine. “Keeping everyone safe during and after a flood must remain our top priority.”

“We must prepare for the food, sanitation and safety needs that may follow a flood of the Green River,” said Council Vice Chair Jane Hague. “These were all major issues during Hurricane Katrina and we need to make sure that we are working with local agencies so that our citizens do not face similar circumstances.”

Hague represents parts of Bellevue on the County Council.

“King County’s partnerships with federal, state, and local organizations are essential in the effort to establish operations that are safe and sanitary, and that provide food, transportation and most importantly information to help flood victims start the recovery process,” said Councilmember Pete von Reichbauer. “The focus is to learn from past events and implement the best practices available. We want people to identify these locations early and know where to go immediately if threatening flood waters strike.”

Kelly said experience has shown that shelters need to be more than “a place for people to put their heads, where they have a dry, warm bed.” She said the County is preparing for shelters to be open for a minimum of two weeks, during which time the function of the shelters shift.

“They need to be places where you can find out about transportation and school schedules, even find out about getting mail,” said Kelly. “After that, we need them to become ‘Disaster Recovery Centers,’ the location you go to when you need information on recovery services.”

“We cannot afford to repeat the mistakes of Katrina. This is why one of our top priorities must be communicating evacuation procedures to the low-income and transit dependent residents of the Green River Valley,” said Councilmember Larry Gossett. “ I am pleased to see the county working with our regional partners and the Red Cross to get the message out about the danger associated with flooding in the valley, the evacuation routes, and the shelters that will be provided to those in need.”

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 Harold Taniguchi, Director of the King County Department of Transportation (KCDOT). He said the County has worked with local cities to identify about 13 potential evacuation routes along 40 miles of roads in unincorporated King County. The cities of Tukwila, Kent, Auburn and Renton have developed their own evacuation plans and the County is working cooperatively with each of them, as well as with the state.

“One of the lessons learned from Katrina is that we must have an evacuation plan that accounts for everyone impacted and doesn’t leave our most vulnerable behind,” said Councilmember Larry Phillips.

At least 10 of the 33 Metro Transit routes that pass through the potential flood zone would have to be suspended if there is flooding, said Taniguchi, but their goal is to keep as many buses running as road conditions permit. He said Metro is working with Sound Transit to carry passengers who would normally ride the Sounder commuter train if that service is disrupted by flooding, and coordinating with local jurisdictions to assist 441 local ACCESS bus users who would need transportation.

“Flooding in the Green River Valley could dramatically hinder mobility across the region,” said Councilmember Julia Patterson. “Highway 167 carries more cars every day than the Alaskan Way Viaduct, and if it’s closed due to flooding the traffic that is diverted could gridlock major transportation corridors like I-5 and I-405. We need to prepare the region and make residents aware of the impacts to their ability to commute.”

To alert residents of unincorporated King County in the upper and middle Green River Valley to the potential threat, letters are being hand-delivered by Sheriff’s deputies working with local fire officials, according to King County Sheriff’s Captain Cam Webster. He said the Sheriff’s Office is now working on outreach to small pockets of unincorporated communities downriver from the dam and on enhanced communication services for the Sheriff’s command post.

All the speakers stressed that their plans, while complete, are “living documents” to be amended as new information comes in.

The U.S. Army Corps of Engineers has been working on interim repairs to the Howard Hanson Dam since last January’s record rain, when sinkholes and rapid seepage of water were discovered in an earthen abutment next to the structure. The Army Corps is working to control that seepage through construction of a “grout curtain,” which consists of a concrete-like substance being injected into the earthen material to slow the flow of water.

Due to the weakened nature of the dam, the Army Corps is limiting the storage capacity of the reservoir until the repair can be tested next spring. Even after interim repairs are completed, the local commander of the Army Corps told the committee last week there is still a “1 in 3 chance” that water may have to be released that could cause the Green River to overtop its banks and flood the valley. He said the odds will improve to 1 in 4 if the levees along the Green River are improved. A permanent fix of the dam will require lining the abutment with a wall of concrete, which will take the federal government three to five years to fund, design and construct.