Glines Canyon Dam Update

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The Skokomish river  has been slowly receding Friday afternoon, with a break in steady rain, and the Elwha river is backing off as well, allowing crews to continue their river restoration work.

February was considerably wetter and colder than normal throughout most of western Washington, including the Elwha Valley. A total of 10.2 inches of rain fell at the Elwha Ranger Station during February, 180 percent of normal for the month, based on records kept from 1981-2010. (See table below.)

The rain has led to higher river levels, with the Elwha flowing at 10,100 cubic feet per second (CFS). With less than 30 feet remaining of the dam and its 'apron', water is completely covering the dam. Contractor crews estimate that flows need to drop to approximately 1,100 CFS in order to work at the dam's current level.

Once water levels drop, the contractor can begin preparations for the next blast. Another item on the to-do list is removing or 'mucking out' the concrete rubble that's accumulated in the river channel during dam deconstruction. A 2.5 yard clamshell bucket is ready to be attached to the giant crane that's perched at the top of the canyon and once flows drop, the crane operator will use the bucket to scoop up and remove the broken concrete. The concrete will then be trucked to a local gravel pit to be crushed and used for road material.

Meanwhile, the cool, wet weather provides good conditions for new transplants in the former reservoirs. Of the 107,000 plants planned for installation this season, crews have planted over 90,000. Planting will wind down later this month, with crews shifting to monitoring in the field and propagating next season's transplants at the park greenhouse.

With the contractors' dam removal work close to completion, park fish biologists are gearing up for an active monitoring season upstream of Glines Canyon. Observers in the field will be ready -- and eager -- to document the first sighting of an adult salmon to return to the upper Elwha.

March 7, 2014/ONP Dam Removal Blog