( CNN ) -- Federal authorities began closing portions of central Louisiana 's Morganza Spillway as the swollen Mississippi River receded Wednesday , reducing the need to divert water down another waterway . The Army Corps of Engineers announced Wednesday that it already had closed three of the 17 open bays at the Morganza Spillway , which was opened May 14 to prevent the Mississippi from flooding New Orleans and Baton Rouge . The Corps said much as 1.2 million gallons ( 172,000 cubic feet ) per second had been pouring through the spillway , which diverted water through the Atchafalaya River basin to the Gulf of Mexico west of New Orleans . The resulting high water has caused some flooding down the Atchafalaya . But the water levels `` continue to be lower than anticipated '' throughout the basin , Corps spokesman Ken Holder said in a statement announcing the decision . The river remained about four feet above flood stage Wednesday night at Bayou Sorrel and about 7 feet over flood stage at Morgan City , on the approaches to the Gulf . But it was more than five feet lower at the town of Krotz Springs and about two feet below flood stage at Butte LaRose , about 20 miles south of the spillway . Rising water levels forced Louisiana authorities to halt boat traffic down a four-mile stretch of the Atchafalaya around the town of Butte LaRose starting Thursday , since the surface of the river had climbed to within seven feet of high-voltage power lines , the Louisiana Department of Wildlife and Fisheries announced . The 125-bay Morganza Spillway was last opened during a 1973 flood .
The spillway was opened May 14 to head off flooding in southern Louisiana . The move diverted water down the Atchafalaya River basin to the Gulf of Mexico . Three of the spillway 's 17 opened bays had been closed by Wednesday .