Kentucky National Guard Sgt. Cornell Marvin, a spokesman for the Kentucky Division of Emergency Management, said most people have sought shelter with family members, though nearly 40 residents were spread out between four shelters.
Officials in Tennessee were concerned that the breathing space provided by the levee break may only be temporary, delaying when the floodwaters crest, because the water that was diverted is beginning to drain back into the Mississippi.
Memphis, where the Mississippi was at 43.8 feet Tuesday, could see a near-record crest of 48 feet on May 11, just inches lower than the record of 48.7 feet in 1937. Water from the Wolf and Loosahatchie rivers already has seeped into parts of the suburbs, and some mobile home parks were swamped.
Emergency officials in Shelby County estimated that 5,300 homes and businesses will likely be affected. Some flooded suburban streets were blocked off because they were already flooded, and about 220 people were staying in shelters. Emergency officials blamed the flooding at least partly on more than 11 inches of rain that have soaked the Memphis area since April 25.
Flooding already has begun in Dyersburg, which is about 70 miles north-northeast of Memphis. Mayor John Holden said that people in parts of that city near the North Fork of the Forked Deer River should evacuate. Farther south, the lower Mississippi River was expected to crest well above flood stages in a region still dealing with the aftermath of last week's deadly tornadoes.
Forecasters say the river could break records in Mississippi set during catastrophic floods in 1927 and a decade later. Gov. Haley Barbour started warning people last week to take precautions if they live in flood-prone areas near the river, comparing the swell of water moving downriver to a pig moving through a python.
With tornados and the threat of rivers gone wild, "we're making a lot of unfortunate history here in Mississippi in April and May," said Jeff Rent, a Mississippi Emergency Management Agency spokesman.
Because the maximum-security Louisiana State Penitentiary at Angola is particularly flood-prone, the state plans to evacuate the most medically vulnerable inmates by next Monday, then other inmates later.
Walsh, of the Army Corps, has made clear he may use other downstream "floodways" — basins surrounded by levees that can be intentionally blown open to divert floodwaters — to try to rein in the trouble.
Among those that could be tapped are the 58-year-old Morganza floodway in central Louisiana and the Bonnet Carre floodway about 30 miles north of New Orleans. The 4-mile-wide Morganza has been pressed into service just once, in 1973. The Bonnet Carre — christened in 1932 — has been opened up nine times since 1937, the most recent in 2008.