ST. LOUIS (AP) — Mississippi River barge operators squeezed by last year’s drought girded Friday against the prospect of new troubles from the waterway now that it’s swollen from heavy rains and threatening to crimp shipments of everything from steel and cement to fertilizer and grain.

Locks being closed at points along the Mississippi that represent important gateways between the Upper Mississippi and points south to the Gulf of Mexico, where grains and other imports make their way to global markets. Idling the locks could snarl barges headed north of St. Louis to Minnesota as well as those southbound from middle America to New Orleans.