WHITE SALMON, Wash. – Crews are working to meet an Aug. 31 target date for removal of Condit Dam more than eight months after a blast of dynamite breached the structure, releasing the White Salmon River to flow freely for the first time in nearly a century.
The 125-foot dam, built in 1913, blocked passage for native species of Pacific salmon and other anadromous fish that mature in the ocean and return to rivers to spawn. The fish had been confined to the lower 3.3 miles of the river.
The owner of the dam, Portland-based utility PacifiCorp, elected to remove the dam rather than install costly fish passage structures that would have been required for relicensing.
Workers were laboring 12 hours a day, six days a week to remove the concrete structure. Some 500 cubic yards of concrete are hauled out each day, the Columbian newspaper reported Thursday.
Workers must keep up that pace if they hope to have it removed by the target date. PacifiCorp project coordinator Todd Olson estimated the removal was about half complete.
“It’s going to be tight,” he said of making the target date.
The White Salmon River winds from its headwaters on the slopes of Mount Adams through steep, forested canyons to its confluence with the Columbia River, the largest river in the Pacific Northwest.
PacifiCorp has graded much of the land that used to be inundated by Northwestern Lake, the reservoir behind the dam, hoping to stabilize it and reduce erosion. Crews will replant the area with natural vegetation later this year, Olson said. Then, they’ll get out of the way.
“Our hope is that Mother Nature just does its thing,” he said. “No one really knows how long that’s going to take.”
Once the dam is gone, rafters will be able to ride the White Salmon River all the way to its mouth at the Columbia River as soon as fall. Many are already using a rebuilt takeout ramp at Northwestern Lake Park, a few miles upstream of Condit Dam.
It’s unclear how fish will respond to the free-flowing river.
A proposed management plan from the National Fisheries Marine Service calls for taking a mostly hands-off approach at first.
“The hope is that we get some recovery, some natural production,” said Rich Turner, a fisheries biologist with the National Oceanic and Atmospheric Administration who was involved in the plan.
Wildlife officials placed fall chinook salmon above the dam before its breaching last year. So far, no other fish have been confirmed on the river, Olson said.
The final price tag of the dam removal project is expected to reach $37 million – about $5 million more than initial estimates, he said.
Costs grew as PacifiCorp worked to stabilize the bridge over the river at Northwestern Lake Park after the reservoir drained.
In addition, PacifiCorp bought one cabin considered unstable due to the river’s shifting banks and plans to demolish it. Two other cabins are also off-limits due to similar safety concerns, and the utility is negotiating with those owners.