Environment
(2009-10-27)
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(KPLU) -
Recent heavy rains have got people in the Green River Valley nervously eying the Howard Hanson Dam in South King County. But officials say they've got things under control, at least for now.
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An abutment adjoining the dam has been leaking since a big rainstorm last January filled the reservoir behind the dam to record levels. The Army Corps of Engineers has been scrambling to reinforce the structure before heavy winter rains begin and says short-term repairs are on schedule to be completed by the end of the month. The Corps' Cassondra Brewster says people in the flood plain don't need to worry about normal rainfall.
"Regular rain events, like what we're having right now, is not where the concern is," Brewster says. "When they hear the word "storm", that's when they need to be plugged in."
Brewster says residents and businesses should make sure they're on the list to be notified of flood warnings.
Right now, the reservoir is more or less empty. But dam operators say there's a one-in-four chance that a heavy rainstorm could force them to release water downstream to prevent the reservoir from filling to unsafe levels. That would likely cause levies in the lower valley to be overtopped, flooding communities from Auburn to Tukwila.
The Army Corps of Engineers is planning a permanent fix for the weakened dam, but that's an estimated three to five years away.
Army Corps of Engineers Flood Maps
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