Floodwaters leave Memphis awash in uncertainty

>>> good evening. it's a flood of historic proportions along the most important waterway in the united states . my one estimate, the water moving down the mississippi right now from memphis and points south is moving at a rate of 2 million cubic feet persecond. they haven't seen this much butter in places like memphis since the post- depression era . from caro to new orleans, they're watching to see where it's going to crest. they won't be able to save everyone, and they know it. we start off with two reports tonight. janet shamlian starting our coverage tonight in memphis , good evening.

>> reporter: they're prepping for the floodwaters in a number of communities along the miss mississip mississippi , but tonight, it's here in memphis that is a city under the siege. the crest is this evening, and they're going to see flood levels they haven't seen here in 60 years. the rising river is cresting tonight, having already swamped hundreds of homes and giving memphis a true case of the blues.

>> last thursday, we walked all the way up to the fence up there, and now it's gone. i mean -- i can't believe this.

>> reporter: the waters are even lapping at the end of downtown's fames beale street where the mighty mississippi is normally a half-mile wide, it's now three times that.

>> we're going to live through this for another few week sas, and it's going to be a nasty one, going to be an expensive one, and there are go going to be dangerous environments to deal with.

>> reporter: much of the area is awash in snake invested muddy soup.

>> we're concerned ability some of the debris and the stuff the water has brought.

>> reporter: there will be no quick relief for submerged neighborhoods like this one. waters won't start to recede for another 48 hours , keeping hundreds in shelters.

>> where's your mommy?

>> reporter: and some of their best friends in safe harbors of their own.

>> they're out of their environment, so we want them to be as comfortable as possible.

>> reporter: 200 pets have been taken in here. their owners will return when they can. down in the mississippi , the water is leaking stlou the levees, a sign that the worst is still to come.

>> we hope it won't do more damage than it's done.

>> reporter: in cities and towns where a river runs through it, janet shamlian , nbc news, memphis .