Vicksburg, Mississippi (CNN) -- Nervous anticipation. That is the feeling permeating through Vicksburg, Mississippi, as it awaits a historic flood crest to wash through the area later this week.
The Mississippi River, already at record levels, is forecast to peak early Thursday more than a foot over the record set in the city in 1927.
As the waters rise, the U.S. Army Corps of Engineers is keeping a watchful eye on the Yazoo Backwater Levee.
"Once we hit the crest on the 19th, it's not over," Henry Dulaney with the U.S. Army Corps of Engineers told CNN affiliate WLBT-TV. "Water is going to be on the levee for another month. And so everything that we've told people, they need to be wary of that for another month, month and a half."
The persistant danger means days off are canceled for Vicksburg police officers.
"We're now finding ourselves having to blanket this city with an added number of officers," Chief Walter Armstrong told WLBT. "Don't walk through it, don't drive through it, and we encourage parents to not allow their children play near or around the floodwaters."
Downstream in Vidalia, Louisiana, residents and officials tried to counter flooding from the rising Mississippi by stacking large containers two- and three-high around riverfront properties.
The U.S. Coast Guard reopened a section of the river there Tuesday 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, Tuesday 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.
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.
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.
In Vidalia, two medical facilities, a hotel and the city's conference and convention center are being protected by temporary flood control barriers, said city spokeswoman Sheri Rabb.
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 Tuesday 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.
By the weekend, floodwaters also are expected to peak at record levels in Natchez, Mississippi, as well as in Red River Landing and Baton Rouge, Louisiana, according to the weather service.
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 along the length of the river and reduce the possibility of devastating flooding in highly populated areas.
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.
Despite the misery and destruction, some residents in flooded areas are trying to make the best of a bad situation.
"You know I always wanted to fish off my front porch, but I never wanted to do it this way," former Poinsett County, Arkansas, Judge Doyle Hillis told CNN affiliate KAIT-TV in the community of Weona. "We've had a lot of laughs over it, but we've had a lot of sad minutes."
Hillis, who has lived in Weona for 66 years, said he would have never thought the water could get that high.
While he wasn't able to land a big catch, he said the fishing helps to keep his mind off the devastation.
"It's going to be a crying shame when the water goes down and they're actually going to see the damage they are going to have," Hillis said.
CNN's John King, Ed Lavandera, Martin Savidge, Ed Payne, Ashley Hayes, Ben Smith and Dave Alsup contributed to this report.
