In the latter part of August 1926, the sky darkened over much of the central United States and a heavy rain began to fall. Rain pelted first Nebraska, South Dakota, Kansas and Oklahoma, then edged eastward into Iowa and Missouri, then Illinois, Indiana, Kentucky and Ohio. The great storm lasted for days. It was followed by another low-pressure system heavy with moisture moving up the Mississippi Valley and pouring precipitation over this same region. And then another.
On September 1, water poured over the banks of dozens of streams and flooded towns from Carroll, Iowa, to Peoria, Illinois, 350 miles apart. On September 4, floods deluged much of Nebraska, Kansas, Iowa, Illinois and Indiana, killing four people. The Mississippi River rose rapidly in the upper Midwest and washed out bridges and railroads. A few days later another storm brought flooding to towns from Terre Haute, Indiana, to Jacksonville, Illinois. Seven people died. More rains fell. On September 13, the Neosho River rose to record heights and roared through southeastern Kansas, killing five. In Iowa, 15 inches of rain fell in three days.
Through September and October, floods in Nebraska, South Dakota, Oklahoma and elsewhere were the greatest ever. At Vicksburg, Mississippi, the river gauge had never exceeded 31 feet in October. That month, it topped 40 feet.
The Mississippi River is not simply a stream that begins in Minnesota and runs south to the Gulf of Mexico. Its fingers stretch from near New York and North Carolina in the east to Idaho and New Mexico in the west. All fall, the rains continued over almost this entire basin. On December 13, in South Dakota the temperature fell 66 degrees in 18 hours, followed by an intense snowstorm. Helena, Montana, received 29.42 inches of snow. In one day, 5.8 inches of rain fell on Little Rock, Arkansas. The Cumberland River rose to the highest level ever recorded and flooded Nashville. The Tennessee River flooded Chattanooga, killing at least 16 and making thousands homeless over Christmas. On New Year’s Day, the Mississippi itself went above flood stage at Cairo, Illinois, and would stay above flood stage for 153 consecutive days. In January, Pittsburgh flooded, Cincinnati flooded, Louisville flooded. To the west, outside Oklahoma City, 14 Mexican migratory workers drowned.
All spring the rains continued, punctuated by five separate storms, each greater than any storm in the preceding ten years. The largest came on Good Friday. From 6 to 15 inches of rain poured down over an area in excess of 100,000 square miles, north into Missouri and Illinois, west into Texas, east almost to Alabama, south to the Gulf. New Orleans received the greatest rainfall ever recorded there; in 18 hours, 14.96 inches fell. Still, New Orleans did not flood, chiefly because the river had broken levees hundreds of miles upstream, so the flood crest never reached the city.
It would become, until Katrina, the nation's greatest disaster. But the story of the 1927 flood, like that of Hurricanes Katrina and Rita, is not simply a story of nature's force. As Gifford Pinchot, then governor of Pennsylvania and a pioneer environmentalist, said after surveying the 1927 destruction, "This isn't a natural disaster. It's a man-made disaster."
Since before the Civil War, the U.S. Army Corps of Engineers had regulated the Mississippi River, and since the 1880s had insisted upon a "levees-only policy"—that is, a belief that levees alone were all that was needed to control flooding. The corps believed that if the quantity of water in a river increases, the current will accelerate. This is generally true. The theory also assumed that a faster current would scour the riverbed more than a slower current, and thus deepen the river. This is also true. But the corps further concluded that such scouring would deepen the river enough to accommodate even a huge flood. This was not true. In fact, all the scientific data about the river up to that time—most of it collected by the corps itself—contradicted that assumption. Nonetheless, the corps opposed building spillways and floodways to let water out of the river, and it had closed off natural reservoirs to maximize the amount of water in the river.
Then, in 1927, the disaster that critics of the corps had long expected finally arrived.
When it was over, the Mississippi River and its tributaries had killed people from Virginia to Oklahoma, flooding the homes of approximately 1 percent of the U.S. population. At its widest point, north of Vicksburg, Mississippi, the river became an inland sea nearly 100 miles across. No one knows the death toll; officially, the government said 500 people died, but a disaster expert who visited the flooded area estimated that more than 1,000 perished in the state of Mississippi alone. The Red Cross fed roughly 650,000 for months, many for a year; 325,000 lived in tents for months, some of them sharing an eight-foot-wide crown of a levee—the only dry ground for miles, with flooded land on one side and the river on the other, their hogs, mules and horses in tow but not their dogs, which were shot for fear of rabies. The worst of the flooding occurred in April and May. Not until September did the floodwaters drain from the land.
The devastation left a legacy of change far beyond the flooded regions—changes that are still being felt today. The first involved the river itself. The 1927 flood ended the debate over the levees-only policy and forced engineers all over the world to look at rivers differently. Most recognized they could not dictate to a great river; they could only accommodate its awesome power.