July 20, 2010 in City

Avista plans summer dam work

Schedule includes north channel, fishery projects
By The Spokesman-Review
 
For more information

Call (509) 495-4998.

Avista Utilities will begin work today on several dam projects along the Spokane River in the downtown Spokane area.

The highly visible work will involve a crane near the Monroe Street Dam, sandbags, water bladders and rock-moving equipment near Upper Falls Dam. It is expected to continue through September.

The projects will “protect and enhance fish, wildlife, water quality, recreation, cultural and aesthetic resources related to its Spokane River hydroelectric power,” said Anna Scarlet, an Avista spokeswoman.

Here’s the schedule:

July 20-Aug. 10: Underwater mapping and sampling of materials in preparation for rock removal and replacement above the Monroe Street Dam. A crane will be placed on the north abutment of the dam, and an unmanned boat will be tethered to the riverbanks near the Monroe Street Bridge.

Sand and gravel accumulate near the dam’s intake and must be removed to maximize generation capacity of the dam.

The crane will remain through Aug. 10.

Aug. 10-Sept. 10: Rock and gravel will be removed above the Monroe Street Dam.

July through September: Over the past century, Spokane’s industrialization changed the flow of the north channel. Work is being done to return it to a more natural state. Water flow may be cut off to the area below the Flour Mill, and the riverbed will go dry.

Similar work is being done on the Upper Falls area, near the Red Lion Inn at the Park.

Meanwhile, fishery work will be done between the Monroe Street Dam and the Upper Falls area.

“The majority of the work will involve a study to assess whether fish can become trapped or stranded in the north channel of the river when water levels are low,” Scarlet said. Thousands of sterile trout will be planted in the area for the first of a three-year fish population count.


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