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Vidalia, Louisiana (CNN) -- Large containers stacked two and three high Tuesday surrounded riverfront properties in Vidalia, Louisiana, Tuesday as residents and officials tried to counter flooding from the rising Mississippi.
The U.S. Coast Guard reopened a section of the river there that it had closed to prevent damage to levees from passing barges.
But officials said only one tow vessel at a time will be allowed to pass through the 15-mile area near Vidalia and Natchez, Mississippi. And they warned they could shut the waterway again if water levels rise to 62.5 feet.
"We will continue to closely monitor transits through the area to ensure the safety of the communities, as well as the towing vessels and their crews," Coast Guard Capt. Michael Gardiner said in a statement.
Vidalia Mayor Hyram Copeland told CNN's "John King USA" the prospect of flooding was a devastating threat in a city that relies on its Mississippi River waterfront and now faces the prospect of extensive infrastructure repairs.
"It's a lifeline of our communities. ... Sometimes it tells you, 'Hey, you think you have me controlled. Let me show you. ... Hopefully, one of these days we can control it a little bit more than we have, but it's the mighty Mississippi," he said.
The river drew to within a finger's length of the highest level recorded at Greenville, Mississippi, as the flood continued to slink its way to the Gulf of Mexico.
Levees along the length of the river appeared to be holding and water diverted through spillways seemed to be rising more slowly than expected, but Louisiana Gov. Bobby Jindal warned residents there's plenty that could go wrong.
"There's still an awful lot of water headed our way, and it's going to be here in many cases for weeks, not just a few days," he said.
HESCO Bastions, which are filled with sand or other material, surround two medical facilities, a hotel and the Vidalia Conference and Convention Center, said city spokeswoman Sheri Rabb. Asked about the bastions' impact, Rabb said: "Unbelievable."
Despite the canceling of convention meetings for May and June, people in the coastal city are going about their daily routine, Rabb said.
"We're big-time open for business," she said.
Sandbags are keeping water out of the convention center, Rabb said Tuesday afternoon, but water covers parking lots and other portions of the riverfront. "We hope to reopen by the end of June."
The city's water supply is thought to be in good shape.
The U.S. Coast Guard reported river closures near Berwick and Morgan City, Louisiana, and at Bayou Chene, where workers submerged a barge to divert floodwaters into wetlands and away from populated areas.
In Mississippi, 4,937 people have been displaced by flooding so far, said Jeff Rent, a spokesman for the state Emergency Management Agency.
In Louisiana, more than 4,000 people had evacuated, Jindal said, citing figures compiled by parish authorities. But, he said, no shelters have been opened in the state.
The crest began passing to little effect Tuesday in Greenville.
A few minor sinkholes have popped up around the Greenville area, but the local levee board has quickly patched them up, Mytries Sutton of the Washington County Emergency Management Agency said. Fewer than 100 structures have been flooded.
The river was cresting Tuesday at Greenville, the National Weather Service reported, with an evening reading of 64.2 feet, more than 16 feet above flood stage.
By the weekend, floodwaters are expected to peak at record levels in Vicksburg, Mississippi, and Natchez, as well as in Red River Landing and Baton Rouge, Louisiana, according to the weather service.
"It is very difficult to grasp the idea of the possibility of our communities flooding," said Mary Beth Hanks, who has a home in New Roads and a fishing camp in Batchelor, Louisiana. "What would we do? Where do we go?"
In Louisiana's Atchafalaya River basin, residents packed up treasured possessions and scrambled to build makeshift levees as federal authorities diverted more water from the swollen Mississippi.
For the first time in its history, the U.S. Army Corps of Engineers has opened three floodways, one in Missouri and two in Louisiana, to ease pressure on levees the length of the river and reduce the possibility of devastating flooding in highly populated areas.
The Corps of Engineers opened two gates in the Morganza Spillway in Louisiana on Saturday, the first release from the facility since 1973. By Monday night, 15 of the structure's 125 bays had been opened, diverting about 102,000 cubic feet (763,000 gallons) of water per second, Corps spokeswoman Rachel Rodi said.
The plan is eventually to open about a quarter of the spillway, according to the agency.
At the Bonne Carre Spillway, which feeds into Lake Pontchartrain, 330 of 350 bays were open, with water coursing through it well above its rated capacity.
"On the river side of the spillway ... the water flowing was rather calm, but as the force of water rushed through the bays, you see its tremendous power," said Diane Truax, a Norco resident, who has been keeping a close eye on the river.
In St. Landry Parish, which is expected to receive some of the water released through the Morganza Spillway, Sheriff Bobby J. Guidroz said that while the National Guard is hard at work building a levee to protect a refinery in Krotz Springs, the biggest job for his deputies is trying to prevent looters from rifling the homes of evacuated residents.
"We're out in boats, trucks and cars," he said.
Louisiana officials Tuesday issued advice to residents in flood-impacted areas on how to prevent snake encounters and bites.
Of the 22 species within the Morganza Spillway, three -- the copperhead, cottonmouth and canebrake rattler -- are venomous.
Butte Larose, Louisiana, where predictions of up to 15 feet of water drove most residents of the 600-home community to evacuate, was a virtual ghost town.
"I moved everything out of the bottom and put everything I could upstairs and brought it to my mother's house," Neil Rabeaix of Butte Larose told CNN affiliate WWL-TV in New Orleans.
Brandi Chiassom loaded a truck full of personal belongings from a home that had just been remodeled.
"All that work. There's nothing we can do. We just pray for the best," Chiassom told CNN affiliate WGNO-TV in New Orleans. "We pretty much know our house will be under water so we're trying to save everything we can."
Officials said the spillway gates are likely to be open for weeks, and it will be weeks before the river falls below flood stage and those who have evacuated can safely return.
The flood is the most significant to hit the lower Mississippi River valley since at least 1937 and has so far affected nine states: Missouri, Illinois, Kentucky, Tennessee, Ohio, Indiana, Arkansas, Louisiana and Mississippi.
In Melville, Louisiana, the rising waters brought back bad memories from the record floods of 1973 and a sense of hopelessness as the Atchafalaya River encroached on Wendy Moreau's home.
"To be honest with you, we don't have no money to start over," she told CNN affiliate KALB-TV in Alexandria, Louisiana. "I don't know what we're going to do, we just live day to day and try to survive."
CNN's John King, Ed Lavandera, Martin Savidge, Justin Lear, Phil Gast, Jacqui Jeras, Mary Grace Lucas, Ed Payne, Ashley Hayes, Ben Smith and Dave Alsup contributed to this report.