Updated

Some of the heaviest rainfall in more than a century swamped parts of the South with flooding Thursday, forcing hundreds of people to flee homes and businesses in Georgia and Tennessee.

Some 300 people left West Point, Ga., 75 miles southwest of Atlanta, as the Chattahoochee River (search) rose toward its highest level since at least 1961, fed by several days of rain from pounding thunderstorms.

"If this rises much more, it could affect four to five times that," said West Point Police Chief David Kerr. "The West Point dam is doing its job, or we'd be completely flooded by now."

Since Wednesday, the swollen Tennessee River (search) has forced as many as 1,600 people out of their homes in the worst flooding to hit Chattanooga, Tenn., in nearly 30 years.

"Ninety-five percent of the people go to a friend's or relative's house," said Don Allen, the Hamilton County emergency services director.

The river level is dropping, but the Tennessee Valley Authority says damage to about 480 Chattanooga buildings already could total $17 million.

In East Ridge, a Chattanooga suburb of about 21,000, about 30 people were rescued by boat and at least 1,000 were displaced Wednesday by flood waters from Chickamauga Creek, a Tennessee River tributary.

The Morehouse family awoke Thursday to find their tile floor underwater.

"We've got about 4 feet of water in our yard," Alina Morehouse said. A neighbor used a canoe to ferry their two dogs to a dry spot down the street.

Tennessee Valley Authority (search) spokesman Gil Francis said the utility was doing everything possible with its dams and reservoirs to limit flooding.

"We've got all the water in tributaries, held back to keep it off Chattanooga," Francis said.

Central Alabama set a record for rainfall in a two-hour period Wednesday, with nearly 11 inches falling near Birmingham. Weather service officials said no higher amount is on record dating back 130 years.

"We had six days of severe weather in a row," said Darone Jones, a National Weather Service meteorologist in Birmingham. "I don't know if that's a record, but I know I'm tired of it."

Alabama Gov. Bob Riley declared a state of emergency in Jefferson County, where rescue workers used boats to navigate flooded streets and help those stranded in homes and businesses. Flooding shut down wastewater treatment pumps in Trussville, sending raw sewage spilling into the Cahaba River.

Tornadoes were blamed for damaging a dozen houses in central Alabama's Shelby County, as well as a church and 26 homes in Munford.

Swollen rivers were still rising across northern Alabama, and anecdotal reports put the floods -- spurred by 5 to 8 inches of rain -- as the worst in the Huntsville area since 1990, said Chris Darden, a weather service meteorologist.