the state making a decision to open the spillway and release water into some communities, burying homes in those communities to protect communities like baton rouge, new orleans, one of the extraordinary measures this state is taking. the stakes are enormous. governor jindal saying $300 million alone in crop damage, tens of millions in other property damage. there are a dozen oil refineries in flood zone. there are chemical factories, homes and businesses as well. listen to governor jindal here explaining the tough decision to open the spillway he says will protect larger communities without a doubt but for the families right in the devastated zone, listen to how many homes could be, could be just buried. >> look, worst case scenario and i don't think the numbers will be this bad. they said 3 million acres under water. 20 to 30,000 people will be flooded. approximately between 11 or 15,000 homes. since then the estimate has been revised. they didn't have to open as much of the spillway as they thought. the good news is that the numbers of people impact ld be lower than that. >> reporter: you hear that noise behind the governor as he speaks? that's a pile driver driving a steel pile into the river bed. they opened that spillway. something else they're doing to stop floodwaters from coming back up into these small communities, they took a 30-foot high steel barge, took it out into the river and sunk it, using rocks to hold it down. using steel pilings -- that's the banging you heard -- to keep the water from coming back up into the waterways, back flooding they call it. building a makeshift dam to divert the water into wetlands and less populated areas, all designed to protect communities here. much more on this story in the hour ahead. i want to begin by giving you a glimpse of what we saw today. we got on an army helicopter. the national guard here up with governor jindal and up with the man who runs the louisiana national guardp you might have to lean forward to hear some of this because of the helicopter noise, but take a remarkable look as louisiana slowly floods. look from above. >> this bank right here 600,000 cubic feet per second of water. >> they were originally thinking they'd use 350,000 feet. they've reduced that and lowered the amount of water they're expecting due to lack water coming in. that's certainly modest good news for the state. there are folks who will have water on their property. they're still saying we won't get to normal levels of water in some places in louisiana until july or august. >> what you have is this water is coming down the spillway. it will be merging with the water that's spilling over the bank of the river. >> you say down below us, how deep will the water get? >> in the basin there are estimates of 20 feet deep. >> when the corps opened the spillway, they estimated 2500 people inside of the spillway, but they estimated outside of the spillway there were 22,000 people impacted. >> these are tough people, they're resilient people, they've been through a lot. they'll get through this. i'm talking to a lot of families. they know exactly where they're going to go to evacuate. the good news is you get people, given the amount of time they've had to forecast -- >> it is stunning when you see it from above essentially controlled flooding. opening that spillway releasing the water sbos the communities. as we were flying over the general from the national guard explaining that the water is rising very slowly. ironically, the reason that it's rising more slow than they expected is that there was a drought before this flood. we're looking down at trees being told if we fly over in a week or two, those trees will be under water. that's the scene here in louisiana as the state rushes to try to prevent damage to more heavily populated areas. if you move up to the roof tops around vicksburg, mississippi tonight, and the river is not expected to crest there for several more day, martin savidge spent the day in vicksburg which has never, never seen flooding like this. >> reporter: john, you're absolutely right. this is the next city that will feel the brunt of this historic flood that is coming down the mississippi. take a look at this. this is a beautiful old historic southern town. this is some of the great architecture you would see. the 1902 railroad station. look at the water right up to the front doors. this is the flooding. let's show you what they're doing to prevent it from getting any worse down here. it is really quite a remarkable engineering feat that they've had to put together in a real hurry. this water came up -- they had warning, but the water came up in the last ten days. look at the construction they've had to build here. the question is will it be enough to hold? basically an old fashioned dike system put together with railroad ties, tar in between. you got these huge steel girders here that are literally backing it up and chains as well as another secondary system. but as you can tell, the water, the pressure that's coming as a result of the water coming downstream is massive, which is why you can see it is just gushing and pouring out of every crack and crevice there is. they've got massive pumps over here that are going around the clock that are trying to pick up the strain and catch the overflow, but right now this is the only thing that is protecting downtown vicksburg in what's called catfish row, which is an historic part of this town. this is the frontlines of the flood here in mississippi. right now they're hoping it's going to hold, but as you say, john, they don't really know because the crest is not here yet. john? >> martin savidge for us. as he noted on the front line in mississippi. this is the front line in louisiana. trying to keep the water out of populated areas, the u.s. army corps of engineers, new orleans office. i know you're very busy. what is your biggest challenge right now? the spillway is open, things seem to be going as predicted. >> now what we're working on is working with the local power, working with the local levy districts to get flood fighting measures in effect that will come down as the water comes down the atchafalaya. >> it look loop back up and catch a community, even a community that has a flood wall here, maybe this stops it but it can come up somewhere else. how do you fight that? >> the system is designed to divert water out to the gulf of mexico. with the low lying marshes and the areas around here, the water before it gets to the gulf, the volume of water is so extreme that it will back up through those marshes and start coming up through the south side. >> how many homes now that you've actually opened the spillway. it was a theory until the weekend. now you've opened the spillway and the water is coming out. how many homes are being buried? how many people will have their homes sacrificed to protect more populated places like this one? >> there are 20,000 residential structures that could be impacted. we're working closely with the local officials to get flooding in place. we're building temporary levees, temporary structures. so we're out here with the levee districts with the national guard to get some protection built up to help those communities. >> not since 1973 had the spillway been opened. this is theory. the engineers work on the models all the time. what has gone, in a way, worse than you predicted? anything? >> the system has gone as functioning. we're starting to divert the flows into the atchafalaya system. the system is under pressure. it will be for a long time. our concern is making sure we're out there on the system, making sure the system is intact while we're still working with the communities to help. >> and when you turn to something like this, this is working. now, we should be able to walk down there. a lot of people do in the evenings. does this tell you even though the water is up higher here than it normally is, does this tell you that opening the spillway, that other steps are working, that you're mitigating the risk to morgan city? >> the wall is the line of protection. it is working like it is. there are things on the riverside that's being impacted. >> we were out on the makeshift dam today. essentially a barge, they drop it down. how long to come up with that? it was done in '73 on a smaller scale. but to be able to do that so quickly. you're in the corps. you've dealt with the frustrations with the corps in the state of louisiana in the past, this time things seem to be working right. >> it was taken from the 1973 concept. the local levee district came up with us. we took a look at it. we were able to permit it and working with the districts and a joint project to get that done out there. it is going very fast. we expect to get that in place in time to be able to help. >> you've will the time to warn people to get out of their communities. a sense now that it will be better than you thought a couple days ago. it is not rising as fast. or do you still have concerns, that it could be worse? >> we're going through a slow opening of the spillway so that the water is making its way downstream. like you touched on the drought condition. so a lot of the overgrowth in the spillway since we last operated it. but other than that, we think that -- i lost it on that one, sorry. >> a busy man. easy to lose your thoughts when you're juggling so many balls. bust best of luck in the days ahead. it is just stunning to see water in places where there's not been water for years. where is it all going to go? chad myers in the weather center. governor jindal and a conversation with the governor just ahead. web browsing on the new blackberry playbook? ♪ flash, aah-ah that's right. it runs flash. so unlike some tablets we could mention, you get the best of the internet - not just part of it. ♪ flash, aah-ah ♪ flash, aah-ah finally, there's a choice for my patients with an irregular heartbeat called atrial fibrillation, or afib, that's not caused by a heart valve problem. today we have pradaxa to reduce the risk of a stroke caused by a clot. in a clinical trial, pradaxa 150 mg reduced stroke risk 35% more than warfarin. and with pradaxa, there's no need for those regular blood tests. pradaxa is progress. pradaxa can cause serious, sometimes fatal, bleeding. don't take pradaxa if you have abnormal bleeding, and seek immediate medical care for unexpected signs of bleeding, like unusual bruising. pradaxa may increase your bleeding risk if you're 75 or older, have kidney problems or a bleeding condition, like stomach ulcers. or if you take aspirin products, nsaids, or blood thinners. tell your doctor about all medicines you take, any planned medical or dental procedures, and don't stop taking pradaxa without your doctor's approval, as stopping may increase your stroke risk. other side effects include indigestion, stomach pain, upset, or burning. if you have afib not caused by a heart valve problem, ask your doctor if pradaxa can reduce your risk of a stroke. you're looking at live pictures here, morgan city, louisiana. no parking on wharf. that means cars, not boats, ladies and gentlemen. the water on that dock is three, four feet high and rising. you could walk down there, you could drive a car down there. this is morgan city. you see how high the water is, the bridge over there. we're standing on the flood wall protecting this town right now as the state of louisiana and the federal government take extraordinary measures to try to keep the water away from more populated communities like morgan city, bigger cities like baton rouge and new orleans, sacrificing low lying areas as part of that effort. before the army corps of engineers began opening the spillway, new orleans wasn't expected to see cresting along the mississippi river until a week from now. but now, everything has changed. chad myers is in the cnn weather center to tell us why. >> up in morganza, the river plit, you get the acha fay lie ya and the mississippi. those gates that they opened were holding the river back from going down the atchafalaya in the first place. concrete metal and wood holding the mississippi basin. now it is not because they've opened some of those spillways, opened some of those doors so the water can go down the atchafalaya in first place. it will make its way down to morgan city. the people that lived in this basin knew this was going to eventually happen. they were hoping not. last time it happened was in '73. morgan city will be seven feet over flood stage. you still have another four feet to go where you are. water will continue to come up as the days go on. but as you said, the mississippi river will not really crest in louisiana south of there any more. so we're getting to about may 17th for baton rouge. may 14th that was over the weekend for new orleans. the crest is over. it won't come up any more now because they've split the flow down one side and to the other side and so evening out the flow compared to what it was. we've also talked about this. the bonnet carre spillway. there's new orleans right there. hard to see, but i'll draw it out for you. it comes down like this and down toward the gulf of mexico. they opened this last week. you can see the bubble of muddy water that's now in lake pontchartrain right there. it eventually makes its way out. but there could still be a problem with the algae bloom later in the season because of all the fertilizer and pesticides in there. i'm going to take you to new orleans and where this entire thing is going to spill out where this morganza spillway will spill. the water will come out of the mississippi river, dirty as it is, whatever it might be. but it will spill where it wants to because it's not being held back any more. it won't be going down the mississippi as much. we're going to take that crest about three feet from where that crest was in new orleans and we're going to bring it down. so let's take you to the morganza area here. this is where the spillway is, that's a bridge, that's a road. they've opened up the dwgates a the water is spilling out. how deep does it go? 15 to 20 feet in some spots. by the time down to you, 7 feet deep or so. but it could have been a lot worse. without any protection at all, this didn't happen because there are, obviously, levees. but without any protection at all, the entire mississippi floods from new orleans down to baton rouge. but there are dam, locks, walls. but without the army corps, new orleans would have flooded again. >> we'll keep in touch with chad. a fascinating thorough explanation there. chad mentioned all the spillways and the levees and everything else. as the corps of engineers open up more of the spillway while the flooding disaster spreads, big towns being protected, more small towns being impacted. ed lavandera shows us this is a slow motion disaster. >> reporter: here on the banks of the atchafalaya river, the water is slowly starting to rise. as the parish president told me a little while ago, this whole process is slow and painful. that's because the floodgates of the morganza spillway are being opened slowly. they opened one on saturday. but as they open each individual gate, that means more water is flowing downstream. up stream they're issuing mandatory evacuations orders. here in butte larose, we believe that those will come by the end of the week. they expect several feet of water here. the initial expectations were 15 feet here in butte larose. 90% of the population has already evacuated from here. people heeding the warning because the water is coming up, all bee it slowly. it will be here for a very long time. john? >> critically important point ed lavandera makes there about the warnings. the mississippi moves so slowly. it's obviously making its way to louisiana right now. you see the higher waters around mere in morgan city. it is time that officials say is their greatest ally. they had time to run simulations to open the morganza spillway. i had a conversation earlier today with governor bobby jindal. you remember him around the country probably. even if you don't pay much attention to louisiana because of his high profile role after the bp oil spill. another disaster striking the state of louisiana. after an exclusive aerial tour we had a conversation with governor jindal about the big challenges just ahead. i'll start, governor by asking your sense of the economic impact of this on your state. >> this will have a tremendous economic impact on a number of different sectors and communities. for example, farmers alone, no good numbers yet, but it will be in the hundreds of millions of dollars of damage. i did a study based on the acreage of flooding in '73, the last time they opened the spillway. those same acres in place there would be $300 million in damage. they're still refining those numbers. you look at the structures that are in harm's way. you look at the fact that you've got chemical plants, refineries, ports, five of the nation's largest ports, 11 of the nation's refineries impacted by this high water. this is significant for the entire country. what's particularly devastating is the family that's in a home. when you zero in, there's a family getting water in their home. they may lose their possessions, they may lose their memories, we do everything we can to keep this water out of people's homes and out of these communities. >> that's progress, the noise. >> true. >> in the sense of how many people? how many people are going to pay that ultimate price of losing their homes? >> worst case they looked at, modeled, 3 million acres under water. 25 to 30,000 people flooded. that's approximately between 11,000 and 15,000 homes or structures. since that time the crest had been revised downwards slightly. they've not had to open up as much of the spillway as they thought. it could impact thousands of homes. by doing this, we'll redirect the water into an unpopulated area, into the wetlands. it will be good to rebuild the wetlands, but rebuild those homes as well. this is incredibly important. this will be done by tomorrow. a great innovative way with the flood waters. this one is being sunk 500 feet along, 30 feet deep. sunk in place with sheet piling and rocks. if you went behind us, it would go to ultimately lake lelore. you got a 20-foot flood wall, the water comes to the spillway, the flood wall protects it but it comes back to the lake. this will stop it from happening. >> on the boat ride out you took a call from the president. your state has been through this before whether an oil spill, katrina, tensions back and forth between local governments, your office, washington. >> i thanked the president. we've had somebody from fema, the corps of engineers, the coast guard, national weather service in our meetings every day. the project going on today is a joint effort. this is the army corps of engineers getting the permit, they're paying for the rock, the state is paying for part of it, the local parishes are paying for part of it. this is a joint effort. i thanked the president. this is an unfortunate event. historic waters going back to 1997. as we speak our communities are working together, folks are doing whatever they can to protect the communities. so i thank the president. his agency are down here working together with local officials as well as the state to fight these floodwaters. i will say this will be a marathon, no t a sprint. we won't be done in a week. this water will be elevated for a number of weeks. we have to work together to get through this. >> when you talk about once in a lifetime moment, you have a once in a lifetime flood, you had a once in a lifetime oil spill, before you were governor, a once in a lifetime hurricane. what goes through your mind? >> we've had four hurricanes, katrina, rita, gustav, mike. we're a tough and resilient people. i was tal