Water releases from Gavins Point Dam on the Missouri River in southeast South Dakota are being halted for about eight hours so officials can inspect spillway damage caused by high water releases during last summer's flooding.
The Army Corps of Engineers and the National Park Service are advising people to use caution Wednesday. The river level is forecast to drop eight feet at Yankton and by a similar amount downstream, and flow levels could change without notice.
Boat ramps and sections of the river might become inaccessible to boats, and officials say people walking on sandbars should be aware that water levels could change quickly.
Officials also say cultural artifacts might surface, and they're reminding the public that federal law prohibits collecting them.