Warmer and drier than normal conditions in the upper Missouri River basin are reflected in the July runoff forecast, which indicates below normal runoff for the remainder of 2012.

The U.S. Army Corps of Engineers predicts current calendar year funoff of 21.4 million acre-feet above Sioux City, Iowa.  That’s 87% of the normal runoff.

“The total volume of water stored in the Missouri River Mainstem Reservoir System on July 1 was 57.6 million acre feet, which means there is enough water to provide good service to all eight of the system’s Congressionally-authorized purposes,” said Jody Farhat, Chief of Water Management.

In accordance with the Master Manual, the water control plan that guides the operations of the six reservoirs, releases will continue to be made to provide full service flows for commercial navigation, as well as to conduct a full-service navigation season.

“In terms of weather conditions, what a difference a year makes,” said Farhat. “We are over the hump in terms of making it through the typical high runoff months: May, June and July.  Runoff so far this year has been slightly below normal. With very little mountain snowpack remaining and the continuing warmer and drier than normal conditions, we are in a more normal mode of operations.”

On April 9, snowpack in the mountains peaked at 97 percent of the normal April 15 peak above Fort Peck.  On March 22, snowpack in the Fort Peck to Garrison reach peaked at 88 percent of the normal April 15 peak. As of July 1, snowpack was 4 percent of the normal April 15 peak above Fort Peck and less than 1 percent of the normal April 15 in the Fort Peck to Garrison reach. In 2011, mountain snowpack peaked at 141 percent of the normal April 15 peak above Fort Peck and 136 percent ofthe normal April 15 peak in the Fort Peck to Garrison reach.

Gavins Point releases averaged 31,700 cubic feet per second during the month of June. The release rate is currently 32,000 cfs and is expected to increase during July in support of navigation and other downstream uses. The normal release rate for this time of year is 35,100 cfs.

The six mainstem power plants generated 950 million kilowatt hours of electricity in June. Typical power generation for the month of June is 840 million kWh. The power plants are projected to generate 9.8 billion kWh hours during calendar year 2012, which is just below the long-term average of 10.0 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, click here.