[Excerpt] The destruction of 35 million acres of wetlands — an area the size of Illinois — in the upper Mississippi River basin has increased flood risks to cities and farms downstream. One way to protect against floods has stood the tests of thousands of years: the ecosystem of wetlands and flood plains natural to big rivers. Instead of letting this ecological infrastructure degrade further, U.S. federal and state authorities should work to expand and rebuild it.
Water levels were extremely high along the Mississippi and other central U.S. rivers on April 29, 2011. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired the top image on April 29, 2011, and the bottom image exactly one year earlier. (NASA images courtesy MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Michon Scott.)
As riverboat casinos close along the lower Mississippi River as a precaution against disastrous flooding, another form of river gambling is coming under the spotlight — the bet that levees will be able to safeguard cities and farms from the rising floodwaters surging south through America’s heartland toward the Gulf of Mexico.
Already the federal Army Corp of Engineers has had to make a decision even the biblical King Solomon would have agonized over. To try to avert a levee failure that would swamp Cairo, Illinois, a town of 2,800 people at the confluence of the Mississippi and Ohio rivers, the Corps decided to blast a two-mile hole in the levee at Birds Point, Missouri. The breach will relieve pressure, at least temporarily, on the levee protecting Cairo, but is expected to inundate 130,000 acres of rich Missouri farmland and some 90 homes.
Unfortunately we’re likely to see more breached, failed and overtopped levees in the future, because for several reasons, the deck is increasingly being stacked against the Mississippi’s levees being able to provide the protection of life and property they once did.
Over the last three-quarters of a century, while engineers were building hundreds of miles of flood-control structures along the river’s banks, the water-holding wetlands in the Mississippi watershed were being drained and filled to make room for more farms and homes. Illinois, Indiana, Iowa, Missouri and Ohio have each lost more than 85 percent of their wetlands. Minnesota, where the Mississippi originates, has lost a whopping 9.3 million acres of wetlands, 62 percent of its pre-industrial total. All together, eight states of the upper Mississippi basin have lost 35 million acres of wetlands, an area the size of Illinois...