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
[Illustration: STRUGGLE TO HOLD THE LEVEE.]
ages of alluvial deposits. Most of the towns are built on high ground; there being a few notable exceptions. A general flood in this valley means that millions of acres of land are submerged, and such crops as are in the fields are destroyed. More frequently, the land is flooded just at planting time, and the land remains wet too long to allow certain crops to be planted in season. Thus, the water in the flooded districts may abate in time to allow a fair cotton crop; while the chance for corn is lost. Fences and small outbuildings are floated away, and often large numbers of stock are drowned; but, after, all, the chief damage is usually indirect: the evil of hindrance rather than of destruction. Further, the retiring water leaves numerous pools and marshes that are rank breeders of malaria, adding vastly to the unhealthiness of the country.