Corps ups Gavins Point releases
OMAHA, Neb. -- Fluctuating river levels caused by cold weather required higher than planned releases from Gavins Point Dam near Yankton during January.
Releases from Gavins Point ranged from 13,000 cubic feet per second to 16,000 cfs during the month, compared to the target winter release of 12,000 cfs.
"Several cold blasts across the lower Missouri River Basin locked river flows into ice and caused repeated dips in river stages downstream of Gavins Point," said Jody Farhat, chief of the Water Management Division.
Releases have been above the target winter release of 12,000 cfs to offset water lost to ice formation and to ensure water intakes remain operational. Once temperatures moderate, releases will be gradually reduced to the target winter release to conserve water in the reservoir system.
Gavins Point releases are currently scheduled at 16,000 cfs.
Based on the current soil moisture and mountain snowpack conditions, forecast runoff in the Missouri River Basin above Sioux City, Iowa, is 26.7 million acre feet (MAF), 106 percent of normal, in 2014. Normal runoff is 25.2 MAF. January runoff into the Missouri River Basin above Sioux City, Iowa, was 175 percent of normal. Runoff typically slows during winter months as rivers freeze over, reducing inflows into the reservoir system; however, intermittent periods of warmer than normal temperatures in Montana, Wyoming, North Dakota and South Dakota contributed to the above normal runoff in January.
Despite the high January runoff, the upper three reservoirs, Fort Peck in eastern Montana, Garrison in North Dakota, and Oahe in South Dakota, remain 5 to 11 feet below the desired operating levels.
As of Feb. 1, the mountain snowpack was 107 percent of normal in the reach above Fort Peck and 113 percent of normal in the reach from Fort Peck to Garrison. Light plains snowpack has accumulated over the eastern Dakotas.
--- Source: Corps of Engineers