ST. LOUIS (AP) — The Army Corps of Engineers on Friday began reducing the flow from a Missouri River reservoir, a move expected to worsen low water conditions on the Mississippi River and potentially bring barge traffic to a halt within weeks.

One result of this year's drought, the worst in decades, has been a big drop in water levels on both the Mississippi and Missouri rivers.

The Corps of Engineers office in Omaha, Neb., announced earlier this month plans to reduce the outflow from the Gavins Point Dam near Yankton, S.D. Corps spokeswoman Monique Farmer told The Associated Press that the reduction began as scheduled Friday morning. By late-morning, the flow that had started at 37,500 cubic feet per second had been cut to 35,500 cubic feet per second.