sound; for human nature is full of rank selfishness, and people who find their property endangered are apt to cut the levee upon the opposite side above them, to relieve themselves by flooding others. Hungry wolves will eat a wounded companion; but man is almost the only animal that seeks an opportunity for wounding his fellow that he may have a pretext for devouring him.
The craw-fish is another persistent enemy of the planter, undermining levees with his numerous tunnels, and even penetrating the low lying fields at a distance from the river, not infrequently damaging the roots of growing crops. The ground becomes like a sponge, and water oozes from the levees in countless places.
There are other objections to the levee system; and while the Mississippi River Commission, and a majority of engineers endorse it, there are not a few equally capable men who denounce it as false in theory, and mischievous in practice. The problem remains a puzzling one. If the floods are unrestrained, a large portion of the river bottom becomes uninhabitable a considerable portion of each year. As to controlling them, a man of much experience said at the time of the flood in 1882, “I have lived on the river for thirty years, and I have studied it, for it was my business to do so. I have been steam-boating all that time. I am now certain that I don’t know anything about it, or about what ought to be done to it.”
Another said, “When God put the river into this valley, He told it to go wherever it pleased, and it always has done so, and always will.”
Yet, the problem can not be considered hopeless, though mere experiments are dangerous. There is little doubt that the levees would have withstood the unprecedented high water of the present year, had it not been aided by the severe and protracted easterly storm. But the levees must remain a constant expense. More than $90,000,000 have already been spent upon them, and the question is an even more vital one than ever.
The chief opponents of the levee system advocate the increase of outlets. A glance at a large-scale map of Louisiana will show the reader how very narrow the mouths of the river are in comparison with its breadth above; and when it is remembered that these passages required deepening ere large vessels could reach New Orleans, it is clear that the outlet men have good reasons for asserting that the proper thing to do is to open as many outlets to the sea as possible. Yet, the majority of engineers declare this to be unscientific, and radically wrong. The levee men propose to narrow the channel and to rely upon the “scour” of the water to keep the river bottom free enough to afford a clear passage to the sea. The “scour” is aided as far as possible by clearing away obstructions where it is desired to maintain a channel, and by placing other obstructions in places where natural shallows have been formed. This is the work carried on by the commission, and is one in theory with that executed by Captain Eads in the South Pass of the Delta. He claimed that if the water flowing through the pass should be confined within comparatively narrow banks, it would scour out the bottom, and so deepen its own bed. The primary result was exactly opposite to this. The water refused to do the work expected of it, and following the law of nature, sought the line of least resistance. Finding the South Pass obstructed, or rather narrowed, much of it turned aside and poured through the Southwest Pass and the Pas a l’Outre, and instead of scouring out the South Pass, scoured the other two to the depth of two feet below where their beds had formerly been. As soon as this was discovered, the two passes were partially dammed up, and the water thus forced through the South Pass.
It is evident, at a glance, that the amount of “scour” will only be as much as will permit ready exit of the water at ordinary stages. The moment that point is reached, the “scour” ceases, and does not again act unless the river be still further narrowed. Hence, this plan, while increasing facility of navigation, only robs Peter to pay Paul, so far as protection is concerned; for what is gained in depth and speed, is necessarily lost in breadth. The “scour” system has even failed to hold its own, and has had to be reinforced by dredging machines.
This last fact tends to confirm the arguments of the outlet advocates. They urge that the immense amount of silt carried by the river is destructive to the entire scheme. During flood time this silt is nearly equally distributed throughout the water. When an overflow occurs, the immense quantity is shown by the vast alluvial deposits left in the submerged region.
According to the believers in the anti-levee theory, if overflows are prevented, the earth held in suspension, instead of being deposited where it will enrich the land, will gradually sink to the bottom of the river. The result will be that the river-bed will be steadily raised until the surface of the water at ordinary stages will be as high as the present floodmarks. Levees will have to be built higher and higher, the river will be raised far above the adjacent country, and should a break occur at any point, the consequence will be disastrous in the extreme. As an example of the effect of confining a silt-bearing alluvial river to its bed, the Hoang-Ho in China is cited. By constant dyking the bottom of the stream has been raised above large tracts of the adjacent country and some of the most