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News Room Headline
Libby Dam increases outflows
Contact: Greg Hoffman, (406) 293-7751, extension 255
June 9, 2003
SEATTLE--Outflows from Libby Dam have recently increased in response to an increase in daily inflow into Lake Koocanusa and a corresponding rise in reservoir elevation. The U.S. Army Corps of Engineers increased discharge from Libby Dam from 4,000 cubic feet per second (cfs) to 7,000 cubic cfs on Sunday, June 1. The following day flows were increased to 10,000 cfs, and then to 15,000 cfs on Tuesday, June 3. Flows were increased to 22,000 cfs on June 5.
The increase in dam discharge coincides with a request from the U.S. Fish and Wildlife Service (USFWS) for flow augmentation for spawning Kootenai River white sturgeon in the Idaho portion of the river. This request was based on the documented spawning of fish that were translocated to an area above the confluence of the Kootenai and Moyie Rivers where river gravels are thought to be better suited for the survival of larval sturgeon than the sand and silt bottom typical below Bonners Ferry, where the fish have historically spawned.
Higher flows are needed to ensure proper conditions for egg incubation and hatching. The USFWS requested that discharge from Libby Dam be maintained above 20,000 cfs for 21 days. Depending on reservoir elevation management needs, the flows may extend slightly beyond.
Lake Koocanusa water levels rose 25 feet during May, bringing the reservoir to within 22 feet of full. Last year the elevation at the end of May was 47 feet from full.
The reason for more water this year is the direct result of substantially lower volume inflow forecasts this year, as compared with last year. The lower volume forecasts this year meant that the reservoir was not drafted as deeply for flood control. The observed mean monthly inflows from January through May 2002 were 95 percent of average. For the same period in 2003 the mean was 77 percent of average. Filling Lake Koocanusa this summer is a priority for the Corps of Engineers.
For more information contact Greg Hoffman at Libby Dam, (406) 293-7751 Ext. 255.
This site is 508 Compliant
Contact: Greg Hoffman, (406) 293-7751, extension 255
June 9, 2003
SEATTLE--Outflows from Libby Dam have recently increased in response to an increase in daily inflow into Lake Koocanusa and a corresponding rise in reservoir elevation. The U.S. Army Corps of Engineers increased discharge from Libby Dam from 4,000 cubic feet per second (cfs) to 7,000 cubic cfs on Sunday, June 1. The following day flows were increased to 10,000 cfs, and then to 15,000 cfs on Tuesday, June 3. Flows were increased to 22,000 cfs on June 5.
The increase in dam discharge coincides with a request from the U.S. Fish and Wildlife Service (USFWS) for flow augmentation for spawning Kootenai River white sturgeon in the Idaho portion of the river. This request was based on the documented spawning of fish that were translocated to an area above the confluence of the Kootenai and Moyie Rivers where river gravels are thought to be better suited for the survival of larval sturgeon than the sand and silt bottom typical below Bonners Ferry, where the fish have historically spawned.
Higher flows are needed to ensure proper conditions for egg incubation and hatching. The USFWS requested that discharge from Libby Dam be maintained above 20,000 cfs for 21 days. Depending on reservoir elevation management needs, the flows may extend slightly beyond.
Lake Koocanusa water levels rose 25 feet during May, bringing the reservoir to within 22 feet of full. Last year the elevation at the end of May was 47 feet from full.
The reason for more water this year is the direct result of substantially lower volume inflow forecasts this year, as compared with last year. The lower volume forecasts this year meant that the reservoir was not drafted as deeply for flood control. The observed mean monthly inflows from January through May 2002 were 95 percent of average. For the same period in 2003 the mean was 77 percent of average. Filling Lake Koocanusa this summer is a priority for the Corps of Engineers.
For more information contact Greg Hoffman at Libby Dam, (406) 293-7751 Ext. 255.