July 31, 2013
Current Koocanusa Reservoir elevation: 2,453.0 feet
Current Koocanusa Reservoir inflow: ~10,000 cubic feet per second
Current Libby Dam outflow: 10,000 cfs
Current Kootenai River elevation at Bonners Ferry: 1,748.7 feet
Libby Dam releases were reduced today from 11,000 cfs to 10,000 cfs. Outflow will be further reduced to 9,000 cfs on Sunday at 11 p.m. MDT. The planned operation for the end of August was to be between 2,452-2,454 feet to try and maintain releases of 9-10,000 kcfs for the month of September, per the state of Montana's System Operation Request (SOR). The elevations and flows discussed previously may not be met given the lack of rainfall and projected dry trend for August. In all likelihood, Libby Dam's elevation at the end of August will be near or below 2449 ft and releases in September will be about 6,000 cfs, the bull trout minimum flow below Libby Dam for September. This operation was coordinated with the Technical Management Team (TMT) on July 30. This operation is consistent with the disposition of the State of Montana's SOR which had provisions to coordinate with TMT in the event the hydrology in the Kootenai Basin was drier or wetter than projected.
The June water supply forecast was issued June 4 and forecasted April-through-August inflow into Koocanusa Reservoir to be 7.074 million-acre-feet, which is 120% of normal. The May forecast set the summer Bull Trout minimum to 9,000 cfs.
The Northwest River Forecast Center creates daily forecasts for short term projections throughout the Kootenai and Columbia River Basins. These forecasts can be updated multiple times in a day and can be updated at anytime as conditions change. Links to those projections can be found below:
Short term forecasts for Libby Dam elevations and inflows can be found here:
Short term forecasts for Libby Dam releases can be found here:
Short term forecasts for Bonners Ferry can be found here:
Please note the National Weather Service's disclaimer on forecasts after 3 days. All forecasts and model projections are based on the best information at the current time, as the weather changes so will the short and long-term predictions.
Libby Dam Operations and associated probabilities for Libby Dam and Bonners Ferry for this spring and summer can be found here:
These modeling results are updated at least weekly and include information on elevations, outflow, and Bonners Ferry seasonal elevation and peak height for the year. Key pieces of information on these plots include things like:
Page 1 shows Lake Koocanusa elevation probability through the summer.
Page 2 shows Libby Dam Outflow probability through the summer.
Page 3 shows Lake Koocanusa elevation probability for a given date.
Page 4 shows Libby Dam Spill probability through the summer.
Page 5 shows Bonners Ferry Stage probability through the summer.
Page 6 shows Bonners Ferry peak stage probability for the year.
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