he Mississippi River began to slowly recede in Memphis while cities and states to the south strengthened their flood-fighting efforts, officials said.
The river had fallen less than 2 inches by Wednesday evening from the unofficial crest of 47.8 feet the day before, The (Memphis) Commercial Appeal reported Thursday.
National Weather Service meteorologist Richard Okulski said the river should fall below the major flood stage of 46 feet by Sunday.
"It should be sometime early next week that we start losing some of the backwater [flooding]," he said.
The Memphis area could get more rain, possibly as much as 1 1/4 inches by Monday, but officials said it shouldn't cause any significant additional flooding.
Anticipated flooding already hit Greenville, Miss., hard, The (Jackson) Clarion-Ledger reported. Casinos have been closed, businesses report furloughing at least 800 people and the Port of Greenville closed public and private terminals to barge traffic, affecting businesses relying on maritime activity.
"There's a lot of reason to be concerned," Gov. Haley Barbour said Wednesday in Greenville during a tour of the Mississippi River. He said "there's no reason for anybody to lose their life in this because we've had days and days and days of warning ... ."
The biggest issue associated with the rising Mississippi River is backwater flooding, Barbour said.
Raising lower portions of a levee was the focus of workers trying to block Mississippi River floodwaters from entering downtown Baton Rouge, La., officials said.
City-parish Department of Public Works workers also were installing Tiger Dam flood systems -- tubes filled with river water and attached to the top of a levee -- to provide 18 additional inches of protection, The (Baton Rouge) Advocate reported Thursday.
Sandbag operations have begun in low areas, said Jim Ferguson, city-parish chief engineer.
Ferguson said crews are working to raise the levee to 51 feet to counter the expected 47.5-foot crest in Baton Rouge May 23.
Besides preparing for a possible flood, Louisiana officials also are preparing for the expected opening of the Morganza Spillway, the Advocate said. The trigger for a decision on opening the spillway is when 1.5 million cubic feet per second of water flows by the gauge at Red River Landing, Gov. Bobby Jindal said.
The river flow will reach the trigger level by Saturday, which could mean opening the Morganza Spillway from Saturday to Tuesday, Jindal said.
St. Mary Parish President Paul Naquin said crews worked to reinforce flood-protection efforts and reviewed evacuation plans if the spillway is opened, The Advocate said.
"Stephenville will be facing a mandatory evacuation once the Morganza floodgates are opened," Naquin said. "We are hoping to avoid this in Amelia."
Naquin told parish residents waterways are being closed and asked them to remove watercraft that could break loose from cuts and bayous. Farmers were asked to move cattle to higher ground.
Several locks, including Wax Lake, Berwick and the Franklin canals, were being closed and reinforced.
Officials expressed concern about barge traffic in New Orleans as the Mississippi's rising water rushed to the delta, WWL-TV, New Orleans, reported. Runaway barges could rupture city water treatment plant pipes.
"The challenge is, the ships coming downriver go a lot faster and it's harder to slow down when you have all that water pushing you," U.S. Coast Guard Chief Petty Officer John Edwards said.
Flooding is expected to kill a significant portion of oyster beds from Lake Borgne to Vermilion Bay, but biologists said the event is good in the long term for oysters, beginning as early as this fall, The (New Orleans) Times-Picayune reported.
"This will be a terrible blow to the industry, to the fishermen, no question," Patrick Banks, biologist in charge of the oyster program for the Louisiana Department of Wildlife and Fisheries, said. "But we know from records that these large freshwater events usually result in greatly improved conditions for production in the future."
The industry was put out of business for most of last year when oyster beds were closed after the BP oil disaster in the Gulf of Mexico.
"Our harvest was down 50 percent last year from 2010, and that's due to the spill closures," Banks said. "So the industry was still fighting to come back from that."