MORGAN CITY, La. (AP) — The Coast Guard says part of Bayou Chene is closed until further notice because the Army Corps of Engineers is sinking a barge there as a temporary floodgate.

A news release Wednesday said Bayou Boeuf is currently the only east-west route between New Orleans and Port Arthur, Texas.

The barge is being sunk below Morgan City to protect residents of five parishes from backwater flooding after the Morganza Spillway is opened on Sunday.

Officials plan to open the spillway partway over several days. They figure that eventually about 150,000 cubic feet (4,250 cubic meters) of water a second will pour down the Morganza Floodway. That's enough to fill the New Orleans aquarium's biggest tank nearly three times a second.

The floodway covers nearly 112 square miles (290 square kilometers). Roughly one-third is used as farmland.