Army Corps sets minimum Missouri River navigation support as runoff lags

OMAHA — The U.S. Army Corps of Engineers said it is setting Gavins Point Dam releases to provide minimum-service navigation flow support on the Missouri River and will end the flow support season early, on Nov 15.

The Corps forecasts 2026 runoff in the Missouri River Basin above Sioux City, Iowa, at 16.3 MAF (million acre-feet), 63% of average. If that forecast is realized, it would be the 14th lowest runoff in the period of record. As of Oct 1, the System stored 46.1 MAF, 10 MAF below the base of its flood control zone. The Corps said Gavins Point releases may be reduced to 9,000 cubic feet per second (cfs) for about two weeks before winter releases of at least 12,000 cfs begin on Dec 1.

The comment period on the draft 2026-2027 Annual Operating Plan closes on Nov 27. The Corps' Northwestern Division will hold public meetings during the week of Oct 26 in Bismarck, Fort Pierre, Sioux City, Smithville and Nebraska City.