Dam flow is increased for sturgeon
Water managers at the U.S. Army Corps of Engineers, along with federal and state fish biologists, determined forecasted inflows are sufficient to provide flow augmentation, including spill, at Libby Dam for endangered Kootenai River white sturgeon in the Kootenai River downstream in Idaho.
Sturgeon flow augmentation began Monday after appropriate conditions were met, including reservoir and river water temperatures, reservoir elevation, and sturgeon behavior in the Kootenai River near Bonners Ferry, Idaho.
Outflows were initially increased to 15,000 cubic feet per second on Monday. Flows increased to 20,000 cfs on Tuesday and were held at that level for three days until switching to full powerhouse capacity (approximately 26,500 cfs).
A spill test of up to 10,000 cfs above powerhouse capacity began June 4 and lasts up to seven days. Outflows from Libby Dam may reach up to 37,000 cfs depending on how much water can be released from the powerhouse.
Biologists and water managers will monitor the spill operation, called for in the 2006 U.S. Fish and Wildlife Service (USFWS) Biological Opinion, as clarified in 2008, to test whether additional flows over the spillway will provide the habitat conditions thought to be necessary for successful sturgeon spawning.
Water temperature and total dissolved gas levels will be monitored by the Corps to ensure they do not exceed criteria established by the Montana Department of Environmental Quality.
Montana Fish, Wildlife and Parks will monitor fish for symptoms of gas bubble trauma.
The flow augmentation operation is part of a collaborative, ongoing effort by regional biologists to enhance spawning and migration conditions for sturgeon in the Kootenai River near Bonners Ferry.
Increased flows are intended to provide river conditions that may foster sturgeon spawning, successful egg hatching, and survival of larval sturgeon in the reach of river upstream of Bonners Ferry, where sturgeon do not currently spawn successfully.
While hatchery reproduction has increased the number of young sturgeon in the river, federal, state, and tribal partners hope to improve habitat conditions for adult sturgeon to successfully reproduce on their own.
The U.S. Army Corps of Engineers’ primary consideration in operating Libby Dam is to minimize risk to human life, health, and safety, while meeting the dam’s multiple purposes and responsibilities.
The sturgeon flow operation will be closely monitored to ensure that the spill test does not exceed flood stage below Libby Dam.
Libby Dam is a multi-purpose water resource developed for flood risk management, hydropower, fish and wildlife, and recreation.
Libby Dam was completed in 1972 as a joint project between the United States and Canada in an effort to provide flood protection and to generate hydroelectric power.
The Kootenai River fluctuated wildly in the spring causing flooding in Montana, Idaho and British Columbia, costing millions of dollars in flood damage.
Congress authorized construction of Libby Dam in 1951 and construction began in 1966.
Libby Dam Visitor Center has a newly remodeled exhibit area, book/gift sales area and auditorium featuring “The Power and Beauty of the Kootenai, the Story of Libby Dam”. Libby Dam Visitor Center will be open from 9:30 am to 6 pm beginning Memorial Day weekend. Guided tours of the dam and powerhouse are from the Visitor Center at 10 am, noon, 2 and 4 pm during the summer season.
The visitor center is located on the west side of the dam and can be reached from the Forest Development Road (FDR) #228. The visitor parking area and boat ramp is open 24 hours a day, seven days a week during the summer. However, the top of the dam is closed to all traffic for security reasons.