Lake Koocanusa

Lake Koocanusa (KUU-KAN-USA) is a reservoir in British Columbia (Canada) and Montana (United States) formed by the damming of the Kootenai River by the Libby Dam in 1972. The Dam was formally dedicated by President Gerald Ford on August 24, 1975.^[1]

The Koocanusa Bridge over Lake Koocanusa from the east bank.

Lake Koocanusa
Lake Koocanusa Show map of Montana Lake Koocanusa Show map of the United States
Location	Montana / British Columbia
Coordinates	48.92°N 115.18°W / 48.92; -115.18
Lake type	reservoir
Primary inflows	Kootenay River (Canada)
Primary outflows	Kootenai River (USA)
Basin countries	United States, Canada
Surface elevation	2,459 feet (750 m)

The lake is formed north of the dam, reaching 48 miles (77 km) to the Canada–United States border and 42 miles (68 km) further into British Columbia. The lake holds 13% of the water in the Columbia River system. The town of Rexford was moved, as well as the Great Northern Railway line. The town of Waldo, British Columbia is now covered by the lake. What was once a barrier to river travel, Jennings Canyon is now inundated by the lake.^[2] The Elk River joins the Kootenay River in the northern part of Lake Koocanusa, within Canadian territory.

Lake Koocanusa was named in a contest won by Alice Beers of Rexford, Montana.^[1] The name is made from the first three letters of the Kootenay (alternately, Kootenai) River, Canada, and USA.

Lake Koocanusa was built as a joint project of the U.S. and Canada. It is 26 km (16 mi) from Libby, Montana, also on the Kootenai River, from which the dam gets its name. Libby Dam has a Visitors Center and can be accessed by the Lake Koocanusa Scenic Byway which begins in the nearby town of Libby, Montana.

The Pacific Northwest National Scenic Trail follows Highway 37 along the east side of the lake before crossing over the Lake Koocanusa Bridge and climbing up Webb Mountain.

Selenium contamination

According to a March 8, 2021 article in The Narwhal, concerns have been raised about selenium pollution leaching from Teck Resources' Elk Valley open pit coal mines' waste rock, which is upstream from the lake system.^[3] A September 24, 2020 Montana Department of Environmental Quality presentation to the Board of Environmental Review Meeting, reported that the 95% of the selenium coming into Lake Koocanusa originates from the Elk River—"which has been contaminated by current and historic coal mining in the Elk Valley." The average selenium levels in Lake Koocanusa were 1 part per billion. Montana has established new standards for selenium—0.8 parts per billion.^[3][4] Because of the high bioaccumulation of selenium in fish, excessive levels of selenium in an aquatic ecosystem has implications for human health.^[5][6] In the spring of 2020, Teck Resources, had "reported a dramatic decline in adult westslope cutthroat trout in Elk Valley waterways closest to its mines".^[3] Since 2015, British Columbia and Montana have agreed to adopt aligned standards for selenium levels by 2020.^[7] Montana's has been in force since the fall of 2020, but British Columbia has not aligned their standards yet.^[7]

Fish

The lake supports a wide variety of fish species. Below is a table detailing the various fish species which may be encountered on the lake.^[8]

Species	Family	Native to MT
Brook Trout	Trout	Introduced
Bull Trout	Trout	Native
Burbot	Codfish	Native
Kokanee	Trout	Introduced
Largemouth Bass	Sunfish	Introduced
Largescale Sucker	Sucker	Native
Longnose Dace	Minnow	Native
Longnose Sucker	Sucker	Native
Mountain Whitefish	Trout	Native
Northern Pike	Pike	Introduced
Northern Pike Minnow	Minnow	Native
Peamouth	Minnow	Native
Pumpkinseed	Sunfish	Introduced
Rainbow Trout	Trout	Introduced
Redside Shiner	Minnow	Native
Westslope Cutthroat Trout	Trout	Native
Yellow Perch	Perch	Introduced

See also

• List of lakes of British Columbia

References

1. "Remarks at Dedication Ceremonies for the Libby Dam, Libby, Montana. | the American Presidency Project".
2. "Libby Dam - the Dams | Balance of Power". Archived from the original on 2011-06-29. Retrieved 2011-07-12.
3. Cruickshank, Ainslie (March 8, 2021). "B.C. under pressure as U.S. EPA releases selenium pollution standard for water near Elk Valley coal mines". The Narwhal. Retrieved March 8, 2021.
4. Kelly, Myla; Sullivan, Lauren (September 24, 2020). Establishing Selenium Standards for Lake Koocanusa and Kootenai River that Protect Aquatic Life (PDF). Montana Department of Environmental Quality Board of Environmental Review Meeting (Report). Water Quality Standards & Modeling Section. Retrieved March 8, 2021.
5. Hamilton, Steven J. (2004-06-29). "Review of selenium toxicity in the aquatic food chain". Science of the Total Environment. 326 (1): 1–31. Bibcode:2004ScTEn.326....1H. doi:10.1016/j.scitotenv.2004.01.019. ISSN 0048-9697. PMID 15142762.
6. Gribble, Matthew; Karimi, Roxanne; Feingold, Beth; Nyland, Jennifer; O'Hara, Todd; Gladyshev, Michail; Chen, Celia (October 8, 2015). "Mercury, selenium and fish oils in marine food webs and implications for human health". Journal of the Marine Biological Association of the United Kingdom. 1 (96): 43–59. doi:10.1017/S0025315415001356. PMC 4720108. PMID 26834292 – via Cambridge.^{[dead link]}
7. Cruickshank, Ainslie (October 8, 2020). "B.C. stalling on new rules for selenium pollution from coal mines, environmental groups say". The Narwhal. Retrieved March 8, 2021.
8. "FISHMT :: Waterbody Details". myfwp.mt.gov. Retrieved 2022-06-17.

External links

• The Libby, Montana, web site with more information about Lake Koocanusa
• Libby Dam, United States Army Corps of Engineers