they're not certain it will hold back the level, depending how high it rises. how fast and how long it stays up. >> where are the flood waters expected to move next? >> reporter: that's a good question. the interesting thing about this disaster is that you can plot it by your calendar. there's no sudden storm that comes in the middle of the night with this one. this is one that you can mark it by the calendar. for instance, on the 16th it's going to be in greenville, mississippi. on the 18th, it's going to be in vicksburg, and then probably in new orleans between the dates of the 24th and the 26th of this month. it takes a while for this huge swath of water to get to where it's going. once it's there, it lingers. then it's going to take a long time. so this is a disaster that's going to be with us for the rest of the month of may, anderson. >> so strange you can plot it so clearly like that. i guess it gives folks some time to prepare. but a lot of folks there's no way to prepare. you have no idea where the water