The U.S. Army Corps of Engineers says warm weather helped them add a half million acre-feet of flood control storage in the Missouri River Mainstem Reservoir System for the runoff season this year.

In response to public concerns about the risk of flooding in 2012 and the fact that many repairs will not be completed prior to the start of the runoff season, the Corps evacuated additional water from the reservoir system.

“The warmer temperatures we’ve seen this winter provided us with a lot of flexibility,” said Jody Farhat, Chief of the Missouri River Water Management Division. “As promised, we have taken advantage of those warmer temperatures to move additional water out of the system and create more flood control storage.”

The total volume of water stored in the reservoir system currently sits at 56.3 million acre feet, 500,000 acre feet below the base of the annual flood control zone.  If temperatures are seasonal during the month of February, the Corps expects to evacuate an additional 100,000 acre feet of water; however warmer than normal temperatures will bring an early start to the runoff season and reservoirs could begin to rise during the month.

Warmer than normal temperatures throughout the basin in the first half of January inhibited ice formation and allowed for above average runoff.

The Corps maintained releases from Gavins Point dam in January at 22,000 cfs.

That’s about 5,000 cfs higher than typical winter releases. 

Warmer temperatures and the lack of river ice below the reservoir system created favorable conditions for maintaining releases at 22,000 cfs through the end of February barring ice-related concerns.