The updated 2023 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, continues to be below average. “Despite some improvements in overall basin conditions, we expect 2023 runoff to remain below average,” says John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division.
“Soil moisture has improved slightly in some areas, but drought conditions still exist across most of the basin.” The 2023 calendar year runoff forecast above Sioux City is 21.5 million acre-feet, 84 percent of the average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.
February runoff in the Missouri River Basin above Sioux City was one million acre-feet, 86 percent of a typical year. System storage is currently 46 million acre-feet, 10.1 million below the top of the carryover multiple-use zone.