Unlike the Missouri levee, these floodways can be opened using gates designed for the purpose, not explosives that unleashed the rush of floodwater into Birds Point that damaged or destroyed as many as 100 homes and washed away crop prospects for this year. Walsh said there are no homes in the Bonnet Carre floodway and only scattered homes and farmland in the Morganza one.
Elsewhere, the Army Corps of Engineers said it was holding water in West Virginia's reservoirs in an attempt to prevent flooding from worsening along the Ohio and Mississippi rivers.
On Tuesday, a group of 25 farmers sued the U.S. government in Missouri, arguing that their land near Birds Point had been taken without adequate compensation.
Agriculture Secretary Tom Vilsack said farmers with crop insurance will be eligible for government reimbursements if their land was flooded. Other help will be available for livestock producers and tree farmers under the same programs designed for natural disasters. People who lost homes may also be eligible for rural housing loans.
Missouri Gov. Jay Nixon said state leaders would push to have the Birds Point levee rebuilt and restore the farmland's productivity. Walsh acknowledged it could be late summer or early fall before the water fully drains off the land, and sediment and moisture could do lasting damage.
After Memphis, the Mississippi is expected to crest May 12 at Helena, Ark., and further south in the following days. Forecasters predict record levels at the towns of Vicksburg and Natchez, Miss.
High water already has shut down nine river casinos in northwest Mississippi's Tunica County, where about 600 residents have been evacuated from flood-prone areas on the inside of the levee, county spokesman Larry Liddell said.
Mississippi officials told about 1,000 people packed at a National Guard armory Wednesday that they're confident the main levees along the Mississippi River will withstand high water levels expected in the coming weeks, but they warn Yazoo backwater levees could be overtopped by as much as a foot.
Peter Nimrod, chief engineer with the Mississippi Levee Board, said people in low areas should secure their property and prepare to leave.
Sherry Hern was at the meeting, trying to find out if she should flee her house on the banks of the Sunflower River near west-central Mississippi.
"Am I scared? Yeah, I am," said Hern, 50.
Hern said the officials used too much technical language, and the unpredictability of the situation left some like Hern wanting a better explanation.
"We're stressed out because we don't know if we're going to get it and they still can't tell me," she said.
Suhr reported from Metropolis and Cairo, Ill. Associated Press writers Jim Salter in Sikeston, Mo., Cain Burdeau in New Orleans, Erik Schelzig in Dyersburg, Tenn., and Holbrook Mohr in Rolling Fork, Miss., contributed to this report.
Copyright 2011 The Associated Press.