The latest 2023 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, is showing improvement. Spring precipitation, including increased mountain snowpack and late-season plains snow, has provided improved runoff conditions.
The 2023 calendar year runoff forecast above Sioux City is 26.4 million acre-feet, 103 percent of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks. March runoff in the Missouri River Basin above Sioux City was 1.7 million acre-feet, 57 percent of average. System storage is currently 46.8 million acre-feet, 9.3 million below the top of the carryover multiple-use zone.
Beginning in mid-March, releases from Gavins Point Dam were adjusted to provide flow support for Missouri River navigation. Navigation flow support for the Missouri River is at minimum service for the first half of the 2023 season, which began April 1 at the mouth of the river near St. Louis, Missouri.