Air Date: Week of May 6, 2011

The record floods and the levee breach designed to protect a town have “Four Fish” author Paul Greenberg thinking we might want to reconsider our engineering of the mighty Mississippi.

Transcript

GELLERMAN: Well from Greensburg to Greenberg - Paul Greenberg, that is. He’s the author of the New York Times best seller “Four Fish: the Future of the Last Wild Food.” He has these thoughts about the current Mississippi floods and the future of the mighty river.

GREENBERG: Back when he was a Mississippi River boat pilot, Mark Twain claims to have seen a catfish "six feet long and weighing 250 pounds.” That’s double the size of the current world sport fishing record. Last week as I motored down the Mississippi, just ahead of the massive storm surge that prompted the Army Corps of Engineers to blow a hole in the river's levees, I couldn't help but think of Twain's big catfish and the particular predicament we've gotten ourselves into with the most engineered river on the planet.

The contemporary Mississippi is very different from the river Twain chronicled. Artificially straightened by planners in the 19th century and then pinched narrow and high by levee building in the 20th, today's river rides above the floodplain it once inundated. All that inundation used to cause annual havoc for farmers who worked the adjacent land. But it also provided nutrients. The pre-colonial Mississippi floodplain was 300 miles wide, draining valuable minerals and organic matter from the Rockies and Appalachians alike, fertilizing fields across the Midwest and the deep South. And it wasn't just fields that were fertilized. During the spring floods, the river spread out wide and got warm. In the tepid, murky shallows, catfish spawned and grew, blessed by an incredible abundance of food. Some of them got very big. Maybe even 250 pounds.

Today, Old Man River's floodplain is less than a mile wide and the catfish are similarly skinny. Instead of feeding catfish and fertilizing fields, all those nutrients are shunted downriver into the Gulf of Mexico. Out at sea, they trigger massive algae blooms and, ironically, a fish-killing dead zone the size of the state of New Jersey.

The logical thing to do would be to give back to the river some of what we've taken. Instead of desperately hauling out explosives whenever the river reaches dangerously high levels, we ought to think about breaching levees in a planned way to get some of that good runoff into the fields where it’s needed. If we were really ambitious, we might even think about reengineering the river, pushing back the levees several miles, opening up the floodplain, lowering the river throughout its range.

Of course, in an era of global warming, where flooding grows more intense by the year, Old Man River may prove to be the ultimate engineer. If he keeps on a-rising, he will eventually burst the levees unaided, violently rolling over everything in his path, reclaiming his former domain. The Mississippi Valley will become a place where nutrients and fertility are once again spread widely throughout the floodplain. It also might just become a place where you could find a 250-pound catfish.

GELLERMAN: Paul Greenberg is the author of “Four Fish: The Future of the Last Wild Food.” It’s just out in paperback.