Rethinking Flood Control: Levee System's Impact...Joe Barrett and Jeffrey Ball, Wall Street Journal
Rethinking Flood Control
Levee System's Impact on Communities, Environment Prompts Look at Alternatives
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The record flood rolling down the Mississippi River is prompting the U.S. Army Corps of Engineers to activate a decades-old flood plan that so far has prevented a catastrophic levee breachbut not without a price.
On Monday, the Corps is expected to open the Bonnet Carr Spillway in Louisiana. The six-mile-long channel runs from the river to Lake Pontchartrain through environmentally sensitive recreational areas that will ease pressure on New Orleans levees.
Late Friday, the Corps warned it may need to open the Morganza Floodway, also in Louisiana, which would lower the river from Baton Rouge to New Orleans but could require the evacuation of a dozen towns.
And last week, the Corps blasted a 2-mile-wide hole in a levee in Missouri to open a floodway, dropping water levels but also submerging 130,000 acres of prime farmland.
Now, the heavy strains on the system and concerns floods are getting more frequent and damaging are sparking a re-examination of flood control. In years past, the call likely would have gone out for higher levees and more so-called gray infrastructureconcrete and cement structures to keep the Mississippi inside its banks. Now some flood experts, along with some states, are saying that trying to control the river won't do the job.
"We need a bend but don't break approach to flood management," said Andrew Fahlund, senior vice president for conservation at American Rivers, a nonprofit group that advocates for more open land and fewer levees and other hard structures that tend to add to flooding problems downstream. "Right now, there's very little bending and the breaking has catastrophic consequences."
Even the Corps itself is in the process of officially changing its approach. For decades, the agency has focused on preventing floods, with the Mississippi flood-control system dating to the aftermath of the great flood of 1927. This summer, it expects to win federal approval for a policy it has begun phasing in over the past several years: allowing more flooding to occur, while working with local and state governments to manage development on surrounding land to reduce economic damage when a flood happens.
The idea is not to dismantle the hard structures, but to use other techniques to prevent the river from getting so high. "Whenever possible, the best way to manage floods is with a natural floodplain," said Terrence "Rock" Salt, the U.S. Army's deputy assistant secretary overseeing the Corps of Engineers' water-resource policy.
But the change won't be easy.
Political battles to control development can dwarf the engineering challenge of building a levee. "People own the land, and they want to develop there," Mr. Salt said. "You end up with what is not a simple proposition."
Sandbagging and evacuations continued Sunday from southern Missouri to Louisiana as the rising water headed further south. The river is expected to crest in Memphis on Tuesday at a near record. Several thousand people there have been forced to evacuate their homes.
A myriad of interests lay claim to the Mississippi: It drains all or parts of 31 states and two Canadian provinces, lies at the heart of the most productive agricultural lands in the U.S. and serves as a major conduit of interstate trade. Control of the river is all the more critical at a time when global demand has driven grain prices sharply higher.
"To abandon the flood plains for crop production would shift the cost of food," said Harold Deckerd, Missouri's assistant state conservationist for water resources. "The cost of food would become astronomical."
Many people concerned about flooding and the long-term interests of different uses for the river call for a balanced approach.
"There's no silver bullet on these big river systems," said Michael Reuter, director of the Nature Conservancy's North America Freshwater Program.
His group backs a blend of options for flood control. These include taking some land out of agricultural use and helping farmers change practices that can contribute to flooding and agricultural run-off that hurts marine life downstream in the Gulf of Mexico.
The Nature Conservancy has bought tracts of land in Illinois and worked with the government to buy others in Louisiana, gradually turning them back into natural wetlands that absorb and filter water from rainfall and floods.
A study by the state of Illinois found that fully exploiting the water absorption capacity of one such tract near Peoria, would reduce flooding in the city by a few inches and affect flood levels as much as 80 miles downstream, Mr. Reuter said.
There are also ways to make flood control work together with agricultureadding retention ponds to slow and filter run-off and trying new crops. "We need to grow more plants that like to get their feet wet," Mr. Reuter said.
Louisiana, meanwhile, is trying to counteract the environmental effects of decades of river engineering by tweaking levees in a way that tries to "mimic what Mother Nature used to do," said Garret Graves, chairman of Louisiana's Coastal Protection and Restoration Authority.
The state is seeking federal approval for more channelsessentially relief valvesthat lead from the river to the Gulf coast. The idea is to recreate natural river branches that once helped drain the Mississippibut that decades of development have closed off.
One thing Louisiana is not considering: breaching levees in a way that lets the river flow uncontrolled by humans. That could jeopardize the Mississippi River's reliability as "America's commerce superhighway," Mr. Graves said. "And that's simply not an option."
Scott Kilman contributed to this article.