MAKING MATS FOR LEVEE FRONTS.
dumped, and various similar means are used to encourage the scour in the shallower parts of the river, and also to prevent the undermining of the natural or artificial banks.
“On a convex shore, where the water is shoal, the levee has been carried along the river edge as near as possible, as there is no danger, under such conditions, of a caving bank. Where the bank is liable to give way, the levees are placed further back, and where a break in the levee itself has occurred from the caving of the bank, loops are made, joining the two broken parts. It must be borne in mind that the banks proper along the river are about forty feet high above low water, and as the river rises five to seven feet over these banks, the levees are constructed of sufficient height to restrain the waters within their proper limits. The material is found on the spot, either clay or sand, as the case may be. A so-called “muck” ditch a few feet wide is dug along the center line of the projected levee, down to where the earth is comparatively free from all organic matter, such as grass and roots of trees. By this method some adhesion to the ground is gained, and the artificial construction is not easily swept away. The earth is taken from the front of the levee line as near the water as the circumstances will permit. Standard levees have a “crown,” or width at the top, of eight feet, except in the case of a very low levee, when the “crown” is not less than its height. The side slopes are one vertical to three or three and one-half horizontal. Present levees are carried up from two to three feet above the high-water mark of their position.”
The river channel, in general, in the upper danger region, adheres to the right side of the valley, and on the left the danger lies chiefly at a few points where the bluffs recede considerably from the river. Throughout the middle and lower flood districts the bends of the stream are so numerous and capricious that the danger lies equally upon either side of the stream. Hence, the levee system is not uniform. The whole alluvial front of the river is leveed on the left bank, the principal line extending from Horn Lake, just below Memphis, to Vicksburg, covering the great Yazoo Basin. On the right bank of the river there are four principal sections which are liable to be overflowed. The first is known as St. Francis front, which runs from Commerce, Missouri, to the St. Francis River. The White River front is the second, extending from Helena, Arkansas, to the mouth of the White and Arkansas Rivers. The third and fourth, known as the Tensas and the Atchafalaya fronts, run respectively from the Arkansas River to the Red River in Louisiana, and from the Red River to New Orleans. The first two sections have received no government work except in limited localities, where it was merely incidental to the work of river improvement undertaken by the commission; and those fronts are everywhere exposed to the overflow, except where private enterprise has done the work. The Social Circle Levee, near Laconia, Arkansas, is an example, and a notable one, of what has been done by the residents. These unprotected tracts have all been submerged, and the low lands turned into an enormous lake.
The overflow waters that pass over the upper part of this section spread over the northeastern part of Arkansas as far back as the high ground, reaching their greatest width about opposite Memphis, and then pass back into the Mississippi by way of the St. Francis River. The overflow below Helena is carried back by the White River. From Arkansas City down, the river, comprising the third and fourth sections, is completely leveed.
Throughout all the lowland districts are hundreds of farms and valuable plantations, the soil being built up by