Libby Dam ramping to full discharge for sturgeon recovery

Outflow at Libby Dam at the south end of Lake Koocanusa is ramping up today to aid migration and spawning conditions for endangered white sturgeon in the Kootenai River.

Water managers at the U.S. Army Corps of Engineers, along with federal, tribal and Idaho fishery biologists, said in a statement Wednesday that spring run-off conditions warranted the increased flow.

The operation needs a volume of water to be released from Libby Dam based on the May water supply forecast for Lake Koocanusa, the border-straddling reservoir formed by Libby Dam. The May forecast this year is 5.19 million-acre-feet, or 88 percent of average. This sets this year’s sturgeon volume at 0.8 million-acre-feet.

Discharge from the dam will increase to full powerhouse capacity, about 25,000 cubic feet per second (cfs), and stay at that level for two weeks. Flow will then be dropped to summer flow — no less than 7,000 cfs, which is the bull trout flow minimum associated with Koocanusa’s inflow forecast.

Outflows will increase to full powerhouse capacity, about 25,000 cubic feet per second (cfs), and stay at that level for two weeks. Flow will then be dropped to summer flow — no less than 7,000 cfs, which is the bull trout flow minimum associated with Koocanusa’s inflow forecast.

The increased flows are meant to provide river conditions that may increase sturgeon migration to the reach of river upstream of Bonners Ferry, in habitat known to be good for successful spawning, egg hatching and survival of larval sturgeon.

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