Crews and local officials make ready for tomorrow’s Condit Dam blast.
PacifiCorp is taking no chances as it makes final plans for the historic breaching of Condit Dam on Wednesday, and state, federal and tribal officials will be working overtime to prevent mishaps as the White Salmon River bursts through a 12-foot-by-18-foot tunnel .
A huge surge of released water and sediment is expected to rush downstream to the river’s mouth and all the way to the Columbia River’s Bonneville Dam. The Army Corps of Engineers is lowering the water behind that dam by two feet to make room for the added volume.
“After the breach, the newly forming river channel will be extremely dangerous, with large amounts of debris and unstable banks,” says PacifiCorp spokesman Tom Gauntt. “This portion of the river will not be open for recreational boating until the fall of 2012.”
Contractors began drilling and dynamiting a tunnel through the 90-foot-thick base of the dam in August and have conducted more than a dozen blasts, boring deeper into the dam with each one. A 10-foot plug remains. That’s what will come out Wednesday, with the detonation of 700 pounds of dynamite.
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