King County could use water-filled barriers and concrete block walls to keep the Green River away from the Maleng Regional Justice Center in Kent.

But members of the King County Council learned this week that if the Green River Valley floods because of the damaged Howard Hanson Dam, the justice center and other county buildings may still be unusable.

“While the county works with cities in the Green River Valley to coordinate mitigation efforts and emergency preparedness, we must also plan for the continuation of County services that impact all of King County,” said Councilmember Bob Ferguson, chair of the Council’s Committee of the Whole, which held its second briefing on the subject Wednesday.

“King County provides critical services and programs that are located in the historic flood plain,” said Councilmember Julia Patterson, who also serves as Chair of the Flood Control District. “It is imperative that we take measures now to protect the County’s facilities and to keep operations running smoothly in the event of a flood.”

The Council’s Committee of the Whole was briefed on plans to minimize damage to county facilities in the historic flood plain while protecting the people who work in or are housed in the buildings.

To help keep water out of buildings like the Regional Justice Center, walls constructed of concrete blocks and plastic sleeves filled with water known as Aqua-Barriers could provide perimeter protection, said Kathy Brown, director of the King County Facilities Management Division. Even with those measures, Brown said, staff will still have to pump out seepage around the walls and address groundwater that rises up inside the buildings.B

rown said the Department of Adult and Juvenile Detention is seeking agreements for locations to house temporarily both the jail inmates at the Justice Center and the courts and justice programs. She said it might be possible to house inmates in detention facilities in Kitsap, Pierce and Snohomish Counties as well as the Federal Detention Facility, while court operations might relocate to the King County Courthouse in Seattle or other owned or leased space.

“The aftermath of Hurricane Katrina taught us how devastating the damage – both human and economic – can be without proper planning,” said Councilmember Larry Gossett, chair of the Council’s Budget and Fiscal Management Committee.

Brown told Councilmembers of a preliminary plan to move the Elections Office out of the Earlington Building in Renton to temporary facilities at the County’s Airport Operations Center by early October to prevent any disruption to the Nov. 3 general election.

Brown said the focus at the King County Animal Shelter in Kent will be on the evacuation and housing of the shelter animals. She estimated housing will also be needed for up to 1,500 stray dogs and cats and 500 large animals and livestock, as well as animals that are found during the flood event, with temporary facilities for pets to be held nearby the emergency shelters where their owners take refuge.

The county will maintain roads as long as possible before they are submerged by floodwaters, said Harold Taniguchi, director of the King County Department of Transportation. He told committee members the department is working on “lifeline route” maps that would inform evacuees of the roads that are the safest to use. DOT is also preparing plans to reroute Metro Transit bus service to ensure that some form of public transportation would continue to be available as long as roads are passable.

Wastewater crews at the South Treatment Plant in Renton will stay on the job and keep the plant operating around the clock, even if they have to sleep at the site and be ferried in and out by airboat, said Jim Faccone, Safety and Health Supervisor with the County’s Wastewater Treatment Division. He said sleeping facilities will be set up, and a week’s worth of food is already in place.

If needed, Faccone said wastewater could be shunted to the West Point Facility in Seattle to relieve pressure on the South Treatment Plant, which lies in what he called “the bottom of the valley” and treats wastewater for the Green River Valley as well as cities as far north as Mill Creek. He warned that if floodwaters shut down the facility, untreated sewage could flow into communities around the plant as well as Lake Washington.

“We’re taking every precaution to protect the lives of county residents, limit the damage to property, move facilities out of the flood zone, and ensure critical county functions continue to operate in case of flooding from the Howard Hanson dam, but the bottom line is that the federal government needs to step up and repair the dam as soon as possible,” said Councilmember Larry Phillips.

The U.S. Army Corps of Engineers discovered sinkholes and rapid seepage of water through an earthen abutment next to the Howard Hanson Dam after last January’s record rain. A temporary fix to inject grout into the earthen material to control seepage is underway, but dam storage capacity will be limited until the repair can be tested next spring. A long-term fix could take three to five years.

Under a worst-case scenario, major County facilities downstream of the federal dam face the threat of flood waters as high as 10 feet. Heavy rains might make it necessary for the Army Corps to release much more water than they have in the past 47 years since the dam was built to avoid overloading the dam abutment.

The County is hosting a series of public meetings on the Howard Hanson flood threat, the first of which is at 6 p.m., Wednesday, Sept. 9, at Green River Community College. For more information go to: www.kingcounty.gov/safety/FloodPlan/Events.aspx