Libby Dam New Year’s week flow update
by Joel Fenolio, P.E., Upper Columbia Senior Water Manager, U.S. Army Corps of Engineers-Seattle District
December 29, 2014
Current Koocanusa Reservoir elevation: 2411.7 feet
Current Koocanusa Reservoir inflow: ~5 kcfs
Current Libby Dam outflow: 20 kcfs
Current Kootenai River elevation at Bonners Ferry: 1754.4 feet
Outflow from Libby Dam will decrease from 20 kcfs to 15 kcfs this morning (Monday, Dec. 29th) starting at 0800 hours and then to 12.5 kcfs by 0200 hours tomorrow morning right after midnight. The 12.5 kcfs is scheduled to be held until 2100 hours tomorrow, but this release will be reevaluated tomorrow morning. Releases from the Dam will by ramped down to 6.5 kcfs by 0500 hours on 31 December. Releases on Thursday will be about 5 kcfs for most of the day and then releases will be 4 kcfs by the January 2nd. The 4 kcfs is anticipated to be held until through January 7th to accommodate maintenance activities at the Dam. Flows after the 7th of January will depend on the first of month water supply forecast and hydrologic conditions.
We are currently drafting the reservoir to meet the flood risk management elevation of 2411 feet by the end of December. This elevation requirement was set by the most recent April-August inflow forecast of 6903 KAF, which is 117 percent of the 1981-2010 average.
The Northwest River Forecast Center creates daily forecasts for short term projections throughout the Kootenai and Columbia River Basins. These forecasts may be updated multiple times in a day and as conditions change. Links to those forecasts can be found below.
Short term forecasts for Libby Dam elevations and inflows:
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
Additionally, projected inflows and reservoir operations at Libby Dam through next summer can be found here:
http://www.nws.usace.army.mil/About/Offices/Engineering/HydraulicsandHydrology/OperationalProjections.aspx
These modeling results are updated at least monthly and include information on elevations, inflow, and outflow:
Page 1 shows Lake Koocanusa elevation probabilities through next summer
Page 2 shows Libby Dam inflow probabilities through next summer
Page 3 shows Libby Dam outflow probabilities through the summer
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