OMAHA, NE – U.S. Army Corps of Engineers is continuing to prepare the Missouri River Mainstem Reservoir System for the upcoming runoff season. Current Gavins Point Dam releases are 21,500 cubic feet per second (cfs). “Higher-than-average runoff during 2017 has allowed us to provide a slightly higher-than-average release during the winter months. Higher winter releases provide additional hydropower generation during the winter, which is one of the peak power demand periods. It also benefits municipal and industrial water intakes below Gavins Point Dam, which can be impacted by low water levels during periods of ice formation. Once evacuation of water stored in the annual flood control pool is complete, releases will be reduced to near normal levels,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. Gavins Point Dam winter releases normally range between 12,000 and 17,000 cfs.
The total volume of water stored in the System is currently 56.3 million acre-feet (MAF), occupying 0.2 MAF of the 16.3 MAF combined flood control storage zones. Based on current soil moisture conditions, plains and mountain snowpack, the 2018 calendar year runoff forecast is 26.6 MAF above Sioux City, IA, 105 percent of average. Average annual runoff is 25.3 MAF.
Flow support for Missouri River navigation will likely be at full service levels for the first half of the 2018 season, which begins on April 1 at the mouth. The actual service level will be based on the total volume of water stored in the System on March 15, in accordance with guidelines in the Master Manual. Flow support for the second half of the navigation season, as well as navigation season length, will be based on the actual July 1 System storage.
Releases from Fort Peck were increased to 10,500 cfs in January and are expected to be increased to 11,000 cfs during February. Releases from Garrison will be gradually increased from 16,000 cfs to 25,000 cfs and will remain near 25,000 cfs during the winter months. River ice formation downstream of all the mainstem projects will be monitored and releases will be adjusted accordingly.
The full monthly report is available at http://go.usa.gov/xnp8n.