Floodwaters continue to rise along the Mississippi River. Already in and around Memphis, Tenn., hundreds of homes are underwater and thousands of people have evacuated to higher ground. More may need to leave their homes in the next couple of days.

The Mississippi River is higher than most people in Memphis have ever seen it before. It is expected to crest Tuesday just under the record high set in 1937.

But the worst of the flooding is along the tributaries — as the mighty river’s high waters push a back-flow up those already swollen tributaries, flooding low-lying neighborhoods.

“The water is behind, it’s right behind my house, but it’s not up to the house yet,” says Anora Brown, who lives in the flooded neighborhood of Frayser.

While watching the rising floodwaters creep along a closed section of U.S. Highway 51 near her home Sunday, Brown admits she’s getting nervous.

“It’s very, very close,” she says. It’s within, let’s say about 12 feet maybe.”

But Brown says if the water rises much higher, she’s ready to evacuate.

At a low-lying mobile home park, the area began filling up with water on Friday.

“My house is full of water,” Marcello Gonzalez says. “I got my two kids and had to bring them over here because I don’t have nowhere to go.”

A shelter is set up in a gymnasium at Hope Presbyterian, a sprawling Megachurch east of Memphis.

With 186 evacuees, Hope’s shelter is beyond capacity. A few hundred people are staying at other shelters in houses of worship around Memphis. Shelby County officials are relying entirely upon the faith-based community to house those displaced by the floods.

“The need is huge,” says Michael Leirer, pastor of missions at Hope Presbyterian.

“From what I’m hearing, the river is going up even more, so within a few days or what not, we’re going to be seeing even more people coming in,” he says.

Leirer is training church members, who are volunteering to staff the shelters, more of which could be opening in coming days.

Officials continued going door-to-door Sunday, and have issued evacuation notices to more than 1,300 homes as the flood zones grow due to the overflowing Wolf and Loosahatchie Rivers and the Nonconnah Creek.

“They flow east to west so they normally dump into the Mississippi,” says Bob Nations, director of the Shelby County Office of Preparedness. “But now they can’t dump into the Mississippi so they’ve been backing up all week because they hit that wall of the Mississippi River rising.”

Nations says evacuation notices are not mandatory and some people are trying to wait it out.

“Hopefully, they won’t wait too long because it’s much easier to evacuate dry than it is to do water evacuations,” he adds.

The Mississippi itself is becoming a bit of a tourist draw in downtown Memphis, with thousands driving over the bridge to Arkansas to view the astoundingly high raging waters, and many stopping along Riverside Drive to see water lapping up to the street.

Col. Vernie Reichling of the Memphis district of the U.S. Army Corps of Engineers says the Mississippi’s levees in the area are performing as designed, and are holding back the water.

“We will continue to monitor these levees and flood walls very carefully, but at this point, there is nothing that we are concerned about and there is no potential possibility of any failures on the Mississippi River levees,” he says.

None-the-less, Reichling warns this is still a dangerous flood of historic proportions moving through Memphis, and down river on towards the Mississippi Delta, Louisiana and New Orleans. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.