Friday, March 25, 2011

Researchers Tracking Passage Success at Upper Deschutes' Ronud Butte Dam

Last year, with construction complete on a multimillion dollar passage structure at Round Butte Dam biologists with Portland General Electric set out to quantify the passage success of spring chinook, steelhead and kokanee through Lake Billy Chinook. Tagging fish in each of the major tributaries and then counting them as they passed through the smolt intake at Round Butte they determined that as many as 50% of spring chinook were successfully passed and 25% of steelhead passed for a grand total of 42,000 and 7,800 smolts respectively. Biologists were also pleasantly surprised that kokanee, long trapped in the lake smolted in excellent numbers with 50,000 of the young sockeye passing through the facility.

The effort is underway to provide access to ESA listed salmonids in the Upper Deschutes, lost when Round Butte was constructed in the 1960's. Biologists only expect passage conditions and survival to improve as annual draw downs and targeted releases of water push fish through the lake and into the structure. Once the passage technique is perfected wild salmon and steelhead will once again have access to the Metolius, Crooked and Upper Deschutes Rivers. More info in an article from the Columbia Basin Bulletin:

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