Corps: Dam Work Lessens Seattle-Area Flood Chance

Hurried repairs this summer at the Howard Hanson Dam have lessened the chances the Green River will flood this winter, the Army Corps of Engineers said Thursday.

In this photo taken Sept. 23, 2009, Workers use a drill and liquid grout to strengthen the Howard...

In this photo taken Sept. 23, 2009, Workers use a drill and liquid grout to strengthen the Howard Hanson Dam, Wednesday, Sept. 23, 2009, near Ravenswood, Wash. Problems with the dam were discovered following record rainfall in January, 2009, and workers are racing to increase the strength of the dam before the traditional rainy season in the fall. (AP Photo/Ted S. Warren)

(AP)

Corps spokeswoman Patricia Graesser in Seattle would not say by how much the odds were improved, saying details would come at a midday news conference.

Previously, the corps has said there was a 1-in-4 chance that a flood would inundate the heavily developed Green River Valley downstream. The corps has been working around the clock to prevent flooding, pumping tons of grout into the problem area, an abutment at the dam that was badly weakened by a torrential storm last winter.

Residents, businesses and local governments in the long, flat valley south of Seattle have been working feverishly to fortify their property and the levees along the winding river against a potentially catastrophic flood during the winter rainy season.

In recent weeks, some 40 miles of levees have been raised with sandbags, evacuation routes and emergency warning systems have been set up, and residents have been urged to assemble "go kits" — documents, medicine and other valuables they'll need if forced to flee on short notice.

Friends and neighbors gathered at Bobby Kendall's place on a recent weekend to help him build a 2-foot barrier of sandbags around his home just a few hundred feet from the river in this Seattle suburb.

"My house is my biggest asset," Kendall said. "I don't want it to wash away or get filled with mud."

A similar effort is under way at a Boeing Co. facility, where workers put up an 8-foot-high floodwall. Managers of a nearby Starbucks roasting plant are in constant communication with federal disaster officials. Other efforts have ranged from homeowners installing one-way valves to prevent toilets backing up, to Boeing erecting the sandbag wall around its sprawling Space Center in nearby Kent.

The valley cities and King County have held scores of informational meetings, passed out hundreds of thousands of sandbags, posted extensive information on special Web sites and organized a "reverse 911" system to automatically call or message residents if an emergency is declared.