Runoff in the Missouri River Basin above Sioux City, Iowa for the month of September was just under 1.0 million acre feet (MAF), 84 percent of average. The 2015 runoff forecast is 24.9 MAF, 98 percent of average. Average annual runoff is 25.3 MAF. The total volume of water stored in the Mainstem Reservoir System is currently 59.3 MAF, occupying 3.2 MAF of the 16.3 MAF combined flood control storage zones. The plan is to evacuate all water stored in the flood zones of the reservoirs prior to the start of next year’s runoff season, which typically begins around March 1.
The U.S. Army Corps of Engineers Missouri River Basin Water Management Division reports runoff in the Missouri River Basin above Sioux City, Iowa, for August was 1.5 million acre feet (MAF), 108 percent of normal. The 2015 runoff forecast is 25.0 MAF, 99 percent of average. Average annual runoff is 25.2 MAF. System storage peaked in early July at 61.9 MAF, occupying 36 percent of the available flood storage.