1 - levee top and backwater
2 - Greenville, Mississippi
3 - Washington Avenue, Greenville, Mississippi
4 - Rolling Fork, Mississippi
5 - main street, Vidaliah, Louisiana
Heavy rains fell over the Mid Mississippi Valley in April of 1927 which flooded down to the lower Mississippi Valley. The river broke through 13 levees along the river which caused widespread flooding that encompassed 26,000 square miles. The catastrophe caused more than a thousand deaths and forced almost a million people from their homes. More than five million acres of farmland were ruined. The flooding occurred from April until June.
There is no stopping the Mississippi floods: they can only be kept under control. In the fall and early winter the level of the river is at its lowest, for although there is a slight rise in November the freezing of the northern tributaries reduces the tendency to a larger flood. In January, early rains in the Ohio valley regions where the land is still frozen cause a quick flow of the water to the Ohio river and, as the snows on the mountains begin to melt, they add to the volume of water carried to the Mississippi. By April the eastern flood waters are ceasing and the Mississippi subsides. The Mississippi valley regions normally get their heaviest rainfall in May and the resultant rise in the water is augmented by flood waters from the Missouri, which enter the Mississippi in June. Seasonal flooding is anticipated but the levees are constructed to control it to some extent. As the height of the water is excessive, however, breaches in the levee walls are deliberately made at certain points to allow particular areas to flood and thus lessen the pressure of water. These are the "backwaters," which occur in the St. Francis Basin to the west of the river between Memphis and Helena, in the great Yazoo-Mississippi Delta north of Vicksburg, in the Tensas Basin west of Natchez, and at other selected points. When freak circumstances occur and the overflow periods clash through the delay of the Ohio floods or the early appearance of the Missouri flood water, even the backwaters cannot take all the excess. By extraordinary ill-fortune all these phenomena occurred together between April and June in 1927 causing the worst flood disaster ever recorded on the Mississippi when millions of tons of water burst through the levees after a period of heavy rainfall and drowned the land.
In the flood of 1882 a person could take a boat from Vicksburg to Monroe (1 inch to the left of Vicksburg on the map), Louisiana, some 80 miles!. This was almost the case in the Flood of 1927.