When the Levee Doesn’t Break

Conway, Ark.

VIOLENT thunderstorms have sent the greatest floods since 1937 cascading down the Ohio and lower Mississippi River Valleys. Residents from Illinois to Arkansas have fled their homes as thousands of square miles of farmland have gone underwater.

But even if the river levels are nearly as high as anything seen in the 20th century, the extent of the damage probably won’t come close to the losses of life and property seen in the historic flood of January 1937. Indeed, while individual stories of calamity abound, taken as a whole the event is a watershed in American history — proof that after nearly 75 years, the federal government has finally gained the upper hand on a river system once thought uncontrollable.

In the Great Flood of 1937 torrential rains pushed rivers up to 15 feet above flood stage and forced a million people from their homes. Entire towns disappeared. Flooding caused around $1 billion in damages. Several hundred people died, mostly from pneumonia or influenza.

Even though there had been calamitous flooding along the lower Mississippi a decade earlier, only a handful of states and cities along the rivers had flood-control systems, while the federal government, adhering to a narrow interpretation of its constitutional powers, had built few flood-control levees or walls, and then mostly along the lower Mississippi.

The government didn’t sit still once the floods hit, though. Hundreds of thousands of volunteers, soldiers and employees of New Deal job-relief programs were deployed along the Mississippi and Ohio Rivers, building emergency levees and aiding displaced residents. On orders from President Franklin D. Roosevelt, the Army was prepared to evacuate people from the entire Mississippi River Valley in the event of a catastrophic levee break.

Then, after the waters receded, the federal government assumed greater control over the nation’s waterways, a move Roosevelt had been advocating for years. Not only would Washington oversee flood control, but it would pay for it, too: over the following decades, the Army Corps of Engineers spent billions of dollars on a vast system of reservoirs, local floodwalls and pumping stations. (Roosevelt initially opposed paying for everything for fear the Corps would neglect issues like conservation and pollution, but once he saw how popular the effort was, he embraced it as his own.)

As this year’s flooding shows, the expense was worth it. In 1937 officials had to move tens of thousands of people from Louisville and Paducah, Ky., to refugee camps; today, despite the rise in the Ohio River, life along its banks goes on normally for almost everyone. Federal outlays after 1937 enabled Memphis to upgrade its floodwalls and pumps; as a result, for many Memphians the floodwaters are now nothing more than a curiosity.

At the same time, increased money for the Weather Bureau — today known as the National Weather Service — helped improve its flood-forecasting abilities, making evacuations more precise. Low confidence in meteorologists’ predictions had sent thousands running in 1937 even though water never reached their doorsteps, while many others waited until it was too late to get out.

True, the system isn’t perfect. The Army Corps of Engineers has relied too much on levees instead of retention reservoirs and less environmentally destructive means of flood reduction like reforestation or erosion control.

And, as the owners of farmland inundated by planned levee breaches can tell you, not everyone benefits from the government’s flood-management efforts.

Nor should we let the success of this year’s flooding response prevent us from making further improvements. In the wake of the 1937 disaster, some scientists and engineers suggested abandoning lowlands to the rivers, but lawmakers and most residents denounced the idea as defeatist and unpatriotic. It’s an idea we should reconsider, at least in particularly flood-prone places.

Indeed, California and other states have already begun experimenting with so-called natural river defenses, in which lands best suited for swamps, marshes and forests have been left undeveloped and open to periodic flooding as a way of lessening the pressure on levees and pumping stations. This was a lesson some communities heeded after 1937; Louisville and other towns, for example, bought out flood victims and turned riverside areas into parks, while utilities moved power plants beyond the water’s reach.

But in too many places, the pressure to develop lands along the river for residential or commercial use has led planners to forget what they learned, raising the risk of terrible losses should a levee break. Smarter engineering, not just higher levees, is needed to make sure the rivers stay under control.

Nevertheless, it’s the spirit of 1937 that we must embrace: The great flood of 2011 would be truly cataclysmic had the Roosevelt administration not invested in public works and embraced the proposition that careful, centralized planning can produce enormous social and economic rewards.