Libby Dam

We have a Libby Dam flow update for you!

The June Water Supply Forecast (WSF) for the April through August inflow period for Koocanusa Reservoir, is 7.064 million acre-feet (116% of average).
The WSF has been well above average through the winter, driven by above normal snowpack at elevation in the upper Kootenay River watershed (https://www.nwrfc.noaa.gov/snow/index.html?version=20201207v1), and Koocanusa Reservoir has been drafted accordingly through the winter and spring. Please see attaches in the comment section.

Current Koocanusa Reservoir elevation is ~ 2,420’ after having reached a low pool elevation of ~ 2,369’ (90’ from full pool and 85’ from target refill elevation).
Current Koocanusa Reservoir inflow is ~ 45,000 cfs after having peaked at ~ 68,000 cfs on May 31.
Current Libby Dam discharge is 25,000 cfs.
Current Bonners Ferry stage is ~ 1,756.5’ (flood stage is 1,764’) after having peaked ~1,757’ on May 30/31.

Koocanusa Reservoir elevation is projected to reach ~2,454’ (full pool elevation for reservoir management purposes) by late July / early August and remain over 2,450’ through most of September.

Libby Dam has been discharging full powerhouse capacity (25,000 cubic feet per second – cfs) since May 26 for Kootenai River white sturgeon spawning in the lower Kootenai River.
Discharge will be reduced to 22,500 cfs late Sunday evening and then reduced to 20,000 cfs on June 11.

Further flow decreases will occur through the end of June, and we expect river flows during July and August to be above the minimum bull trout flow of 9,000 cfs for this year before reducing discharge to the bull trout minimum flow in late August / early September.

More detailed flow updates will be provided as they are coordinated to occur, as described above.
Details are also available via the links below.

US Army Corps of Engineers Libby Dam Water Management Data:
https://water.usace.army.mil/overview/nws/locations/lib

Short term forecasts for Libby Dam elevations and inflow:
http://www.nwrfc.noaa.gov/river/station/flowplot/flowplot.cgi?lid=LYDM8

Short term forecasts for Libby Dam outflow:
http://www.nwrfc.noaa.gov/river/station/flowplot/flowplot.cgi?lid=KBDM8

No surprise here that our dam's dark, cavernous spaces aren't just great for generating hydropower. They're also a favorite hangout spot for local bats! 🦇🦇

Surveys conducted between 2011–2012 identified nine bat species roosting in or near our Visitor Center?? We've seen Little Brown Myotis, Yuma Myotis, California Myotis, Hoary Bat, Big Brown Bat, Townsend’s Big-eared Bat, Silver-haired Bat, Western Long-eared Myotis, and Small-footed Myotis!! 😮🤷‍♀️🤷‍♂️

To check in on our nocturnal neighbors, we stayed up way past our bedtime and teamed up with Montana Fish, Wildlife & Parks to conduct a late-night field session to safely capture and monitor local bat species right here on site.

Our main mission was checking them for White-Nose Syndrome, a devastating fungal disease affecting bats across North America. Catching it early is key to keeping our local colonies healthy.

Wangling bats in the dark might sound like a funny way to spend a shift, but these little guys are the unsung heroes of our ecosystem. A single little brown bat can eat its own body weight in bugs every single night. By keeping pests in check, they protect the beautiful Montana forests and lands we all love.

Healthy Bats ➡️ Natural Pest Control ➡️ Thriving Montana Ecosystem ✅

We’re proud to team up with Montana FWP to look out for our winged allies, so they can keep doing their vital work under the cover of darkness! U.S. Army Corps of Engineers, Seattle District