MEMPHIS, Tenn The rising Mississippi river lapped over downtown Memphis streets on Thursday as a massive wall of water threatened to unleash near record flooding all the way to the Gulf of Mexico.
Water lapped over Riverside Drive and onto Beale Street in Memphis, and threatened some homes on Mud Island, a community of about 5,000 residents with a river theme park. The island connects to downtown Memphis by a bridge and causeway.
Emergency officials in Millington near Memphis were "going door-to-door, asking people to leave," according to the Tennessee Emergency Management Agency.
Large amounts of rain and melt from the winter snow has caused a chain reaction of flooding from Canada and the Dakotas through Illinois, Indiana, Missouri, Kentucky, Arkansas and Tennessee. It is expected to soon hit Mississippi and Louisiana at the mouth of the Mississippi River.
The flood threat harkens back to memories from the aftermath of Hurricane Katrina in which Mississippi beachfront towns were engulfed and most of New Orleans went under water after its levee system failed.
"The flood is rolling down, it is breaking records as it moves down and it is one of those wait-and-see type of things as to how massive it is going to be when it's all said and done," said Charles Camillo, historian for the Mississippi River Commission and the Mississippi River and Tributaries Project.
In Arkansas, westbound traffic on a section of one of the nation's major trucking arteries, Interstate 40, was closed for a second day due to flooding.
The White River was expected to crest at its highest ever level of 40 feet at Des Arc, Arkansas on Thursday night, breaking a 1949 record.
A levee overflowed near the White River, forcing a mandatory evacuation of the town of Cotton Plant, the Arkansas Department of Emergency Management said.
Officials at the Shelby County Office of Preparedness, that includes Memphis, predicted that the flood could affect 2,832 properties if it crests at 48 feet this coming weekend.
A crest of 48 feet would be the river's highest level since 1937, according to the National Weather Service. The service currently puts the river level at Memphis at 45.21 feet, with an expected rise to 47.6 feet by Monday morning.
The flooding is also affecting towns not directly on the Mississippi. Residents in south Dyersburg, Tenn., about 20 miles from the Mississippi, have been asked to evacuate because of the projected crest of the North Fork of the Forked Deer River, which runs into the big river.
North of Memphis upstream, the U.S. Army Corps of Engineers blew up a third section of a Missouri levee Thursday afternoon to let flood waters back into the Mississippi.
The Corps blew up a two-mile section of the Birds Point levee Monday night to help ease flooding in Illinois and Kentucky. The levee destruction resulted in the flooding of 130,000 acres of Missouri farmland. The Corps then blew up two smaller sections of the levee Tuesday and Thursday to let water back in the river.
President Barack Obama on Wednesday declared parts of Kentucky, Mississippi and Tennessee as disaster areas due to flooding. Missouri Governor Jay Nixon Thursday requested that Obama make a major disaster declaration for the state as a result of high winds, tornadoes and flooding since April 19.
The levee system in Mississippi is holding for now but it has never been tested like this before, officials said.
"Compared to the Great Mississippi Flood of 1927 this flood is going to be a lot nastier," said Marty Pope, senior hydrologist for the National Weather Service in Jackson, Miss.
The river is predicted to crest at 64.5 feet on May 17 in the Vicksburg, Miss. area. Vicksburg has a flood stage of 48 feet, which means the river will crest more than 16 feet above normal, according to flood experts at the National Weather Service.
The flood waters will reach more than a foot above the Yazoo Backwater Levee near Yazoo City, Miss. and this will flood thousands of acres of farmland, said Pope.
There were major floods on the Mississippi in 1927, 1937, 1973, 1993 and 2008. The 1927 flood caused up to 1,000 deaths and left 600,000 homeless. Floodways were adopted as a response.
Camillo said it was too early to estimate expected damage from the 2011 flooding. He noted that much has changed since the 1927 flood, including the structure of the levees and the addition of dozens of reservoirs throughout the Mississippi River basin and floodways.
The Mississippi has four floodways: Birds Point and three spillways in Louisiana.
"There is a very good possibility that we would operate three floodways ... and we have never done that before," Camillo said. (Additional reporting by David Bailey in Minneapolis, Tim Ghianni in Nashville, Suzi Parker in Little Rock and Leigh Coleman in Biloxi, Mississippi; Writing by Mary Wisniewski; Editing by Greg McCune, Bernard Orr)