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InterviewsJohn M. Barry

Great Projects: The Building of America

INT: Explain the shifting river phenomenon.

JB: If you imagine a garden hose and you lay it out on the grass and you turn the water pressure up, after a while the hose'll start to bounce around. And that's exactly what happens with the Mississippi River. It deposited sediment in one place, at its mouth, and that would build up the land there. So then it would naturally want to roll off to someplace where the land was lower. And then it would deposit sediment there, build it up, and then roll off, and then it would shift sideways back and forth from east to the State of Mississippi, west almost to Texas. And the current mouth of the river's only been there seven or eight hundred years. Forget about geological time in terms of eons. I mean we're talking about a few hundred years; not much more -- longer than before Columbus discovered America. So it's really a recent phenomenon.

INT: Can you hear the crest come?

JB: No. People think of a flood crest if you don't live near a river maybe as an ocean wave. But that's not it at all. It's much more gradual. And it's not something that you see coming down the river. You watch the river rise. If it's rising really rapidly, it might go an inch an hour. That's fast. That's a couple feet a day. On extremely rare occasions, at least when you're talking about the Mississippi, which, obviously, takes a lot of water to affect it, it might go faster than that. But when the crest comes, it usually hangs around for a while. That's another thing about floods on the Mississippi; they tend to be slow. So it's an enemy that you have to fight against over an extended period of time. And the river is perfect. Man is not perfect. So if man makes a mistake against the Mississippi, the river is certain to find it, and if it has time, it will exploit it.

INT: Through what kind of mistake?

JB: Well, there are a lot of mistakes you could make. One is a policy mistake, such as the levees-only policy. The other is some weakness in the levee. It needs to be maintained. They can settle. You have to keep rebuilding them. There's a levee, a fairly lengthy stretch of levee, in the state of Mississippi right now that is eight feet below grade for Project Flood. Eight feet is an enormous distance. I mean that is a lot of water. Eight feet of water, you know, a mile wide moving at eight or nine miles an hour, just think of how much water that is that you've got to take care of for eight feet. But there are a lot of little things that can destroy a levee. In the old days -- this doesn't happen anymore -- but if during the construction somebody left a log or even really a branch in the levee, it rots and creates a cavity. That's a weakness. When the water saturates a levee, which it will do automatically in a flood, it finds that little cavity and starts to eat away at it. Even some crawfish nests. A crawfish builds a nest in the levee and that -- that's a cavity. The water comes in and starts to erode that, and pure pressure as well. Just the weight of the water pressing against the sides will push water through the levee and it'll come out on the other side. Some of this seepage is perfectly safe. Some of it is quite dangerous. And you can get what's called sand boils and a sand boil is really like a miniature volcano. It looks just like a volcano, and it'll spout water in a sort of a gusher. If the water is clear, then it's safe. But if the water is muddy, that means that it's eroding the levee. The water, as it runs through the levee, is taking the earth of the levee with it. And that has to be taken care of immediately. And, again, just the constant pressure of the water against the levee, the levee can slough off. That has to be supported. I mean there are an infinite number of problems that can arise.

INT: Describe how houses were swept off foundations.

JB: Well, you've got to understand that when there's a crevasse, it's not simply the water flowing over the top of the levee as if it were overflowing a bath tub. What you get is tremendous turbulence, unbelievable forces at work, and in a great crevasse the river will gouge out a hole in the earth and the greatest crevasse on record, which was in 1927 about 15 miles north of Greenville, Mississippi, you know, the hole in the levee was about two-thirds of a mile wide. And they sounded it with a hundred-foot line and found no bottom. It was later they figured out that it was 130 feet deep. So you had this hole, you know, over, as I said, about two-thirds of a mile wide, 130 feet deep pouring water onto the land. Obviously, that is a ferocious current when it first hits the land. So a house is not gonna stand up to that under any circumstances. In fact, trees, forests, whatever, they're just simply wiped out, but as the water spreads out and slows down, you know, people with some experience in the delta would, for example, leave their doors open to f allow the water into the house, 'cause if they closed everything off, then it had this resistance and it would -- it would just, you know, undermine it or overpower it. But if they let the doors and windows open, the water could flow through it. That was one of devices for people who had experience with floods.

You know, the 1927 Flood was two stories. It was man against nature, but it was also man against man. And part of the story in man against man involved the city of New Orleans, which in 1927 was a much more vibrant and vital city than it is today. It was, by far, the leading city in the South, economically dwarfed, literally double and triple Miami, Houston, Dallas, Nashville, Louisville, any of its rivals. And one of the things that the people in New Orleans who ran the city were concerned about was fear of their investors, who were mostly in New York and Boston, of what the Mississippi River might do to New Orleans in a big flood. So here, you had this tremendous flood coming down the river and, oddly enough, it didn't threaten New Orleans. And the reason it didn't threaten New Orleans was because there was no possible way that that water was ever going to make it to New Orleans. The levees upriver had to break. They had to, as, in fact, they did. For example, the river spread out 70 miles from Vicksburg to Monroe, Louisiana. But before that happened, while people in New York were worrying about whether or not they should put more money into New Orleans and invest in the port and so forth, the city fathers decided to demonstrate that they would never, under any circumstances, allow the river to threaten the city. So what they did was decide to dynamite the levee about 13 miles below the city and flood out their neighbors. Race had nothing to do with this. They were almost all poor whites who were flooded out.

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