South Sound faces deluge

Thurston County emergency management officials urged residents in flood-prone areas to evacuate as near-record flooding loomed on the Chehalis, Deschutes and Skookumchuck rivers, shelters opened and a submerged section of Interstate 5 closed for the second time in 14 months.

"We're looking at one of the most significant flood events of this century," said Ted Buehner, a meteorologist with the National Weather Service in Seattle.

South Sound rivers began reaching flood stage Wednesday night after a whopper of a Western Washington rainstorm that began Tuesday night and wasn't expected to end until today.

Authorities went door-to-door or called several hundred river valley residents Wednesday, warning them of potential overnight flood danger that likely would carry into the day.

'Don't wait for the water'

"If you live in areas that have seen floodwaters before, don't wait for the water — leave now," county emergency management spokesman Keith Eisner said.

Several emergency shelters opened Wednesday night, including the LDS Church at 18501 Paulson Road S.W., Rochester; two shelters in Centralia; one in Chehalis; and two elsewhere in Lewis County.

Numerous roads closed Wednesday in South Sound because of landslides and water over the roads, and more than 3 inches of rain fell on soil already saturated by melting snow from the December storms.

An additional 1.27 inches of rain was predicted for Olympia from Wednesday afternoon through this morning.

The rain should subside, leading to drier weather over the weekend, but the flooding on the major rivers and landslide threat will continue after the rain ends, Buehner said.

"It takes a while for all that water to move downstream," he said.

River breakdown

Here's a breakdown of the major South Sound rivers and flood conditions as predicted by the National Weather Service.

• Deschutes River: Minor flooding began on the Deschutes on Wednesday afternoon, and the river was predicted to rise to a near-record 6 feet above flood stage near Rainier early today.

Rivers, roads and the Tumwater Valley all are expected to be submerged in floodwaters today.

It's not clear whether the floodwaters entering Capitol Lake will overflow into Heritage Park and nearby businesses in downtown Olympia, or escape out the Fifth Avenue dam into Budd Inlet.

"It doesn't look good," said Larry Kessel, who helps manage the lake for the state Department of General Administration.

He said lake flooding could occur this afternoon because the low tide around 9 a.m. is too high to allow much water release from the lake into Budd Inlet.

The hope is that any flooding can be contained to Heritage Park, which was landscaped to catch floodwaters before they reach city streets.

"The park is our first line of defense," he said.

• Nisqually River: Tacoma Power began increasing flows out of the Alder and LaGrande dams Wednesday afternoon, bumping them from 2,000 cubic feet per second to 10,000 cubic feet per second to keep up with heavy rainfall. The river was expected to reach flood stage at McKenna on Wednesday night and crest in the lower river areas about 4 a.m. today, about 1.4 feet above flood stage. Minor flooding was predicted to last through the day.

The National Park Service closed the Mount Rainier National Park Nisqually entrance Wednesday night to protect the public from possible flooding in the park.

• Skookumchuck River: The south county river is expected to crest 4.4 feet above flood stage about 4 p.m. today. If it does, Bucoda businesses and residences could experience severe, near-record flooding.

• Chehalis River: In the Grand Mound-Rochester area, the state's second-largest river was expected to rise above flood stage Wednesday night and crest six feet above flood stage about 10 p.m. today.

The flooding in south county could be comparable with what happened in December 2007, Eisner said. Deep, swift flood waters are likely to inundate the Independence Valley, home to several commercial organic farms.