Mississippi floods: Thousands flee as floodgates open
Thousands have evacuated the US state of Louisiana after floodgates were opened on Saturday to relieve pressure from the swollen Mississippi River.
More floodgates are to be opened in the coming days to help save more populated areas like Baton Rouge and New Orleans.
The man-made floods will damage thousands of homes and hundreds of thousands of acres of farmland.
Meanwhile, President Barack Obama met families affected by flooding in Memphis in Tennessee on Tuesday.
The president, who was driven past the bulging Mississippi, also spoke to local officials and emergency responders who confronted the region's highest waters since 1937.
Seeking higher ground
Sheriff's deputies and National Guardsmen have been knocking on the front doors of residents along the Mississippi River in Louisiana since Saturday and ordering them to leave.
Most residents heeded the warnings and headed for higher ground; by Monday, some areas were virtually empty as the water from the Mississippi River slowly rolled across the Atchafalaya River basin, the Associated Press news agency reported.
About 2,000 people were reportedly ordered to evacuate from the town of St Landry Parish alone.
Opening the Morganza Spillway floodgates is set to inundate up to 3,000 sq miles (7,770 sq km) of land in an attempt to protect large cities along the Mississippi River, which forms a large section of the border between Louisiana and Mississippi states.
About 25,000 people and 11,000 buildings could be adversely affected.
"They say we have to leave town. We have nowhere to go," Louisiana resident Mary Ryder was quoted by AP as saying.
Ms Ryder and her fiance were ordered to evacuate from Melville, a town where some mandatory evacuations took place early on Monday.
She and her fiance intended to drive their possessions over the levee to stay with relatives on the other side of town.
"What are we going to do? I have no idea. We need help up here," Ms Ryder said, adding that the entire town could soon be ordered to evacuate.
It will be at least a week before the peak of the Mississippi River arrives at the spillway, where officials opened two massive gates on Saturday and another two on Sunday. There are 125 gates in total.
Fed by rainwater and the spring thaw, the Mississippi and its tributaries have caused massive flooding upstream, and officials have said the flooding in Louisiana is the worst since 1927.
Water will flow south, but slowly to give people enough time to leave before the flood waters reach them, officials say.
The flood waters are expected to inundate homes and farms in the state's Cajun country under an expected 10-20ft (3-7m) of water.
The Morganza Spillway, 45 miles (72km) north-west of Baton Rouge, was last opened in 1973.
The spillway stands above the Mississippi's normal water level, and comes into play only when the Mississippi is already swollen and endangering the surrounding areas.
By opening its floodgates, engineers are able to control the flow of the flood waters, diverting them around Baton Rouge into the Atchafalaya river basin, a low-lying area of central Louisiana.
Over several days, the water should run south to Morgan City - where workers are rushing to reinforces levees - and then into the Gulf of Mexico.
Opening all 125 gates on the spillway would release 600,000 cubic ft of water every second.
Meanwhile, the US Army Corps of Engineers moved a fifth dredge to dig sediment out of the Southwest Pass, a major shipping connection between the Gulf of Mexico and the Mississippi River, in an effort to keep it open.
The Mississippi sends large amounts of sediment down river when its water levels are higher than normal, and the dredges were being used on Monday to keep the channel open.
Shipping is expected to continue largely unhindered in the lower Mississippi River, the Coast Guard said over the weekend.
Seven states are affected by the continuing floods.