Flood-prone areas awash in development
Published February 19, 2006
ST. LOUIS - Concentrated development in flood-prone parts of Missouri, California and other states has significantly raised the risk of New Orleans-style flooding as people snap up new homes even in areas recently deluged, researchers said Saturday.
Around St. Louis, where the Mississippi River lapped at the steps of the Gateway Arch during the 1993 flood, more than 14,000 acres of flood plain have been developed since then. That has reduced the region's ability to store water during future floods and potentially put more people in harm's way, said Adolphus Busch IV, a scion of the Anheuser-Busch brewing family who is chairman of the Great Rivers Habitat Alliance.
Similar development has occurred around Dallas, Kansas City, Mo., Los Angeles, Omaha, Neb., and Sacramento, Calif., said Gerald Galloway, a professor of engineering at the University of Maryland.
"The half-life of the memory of a flood is very short. You can already hear it in Washington, D.C.: New Orleans where?" Galloway said of the lack of action in the aftermath of Hurricane Katrina last summer.
The research was presented Saturday at the annual meeting of the American Association for the Advancement of Science.
In California, development in the Sacramento-San Joaquin delta, where flood control efforts first started in the mid 1800s, represents a major risk to cities such as Stockton as they expand, said Jeffrey Mount, a professor of geology at the University of California at Davis.
"We are reinventing Katrina all over again," Mount said. He estimates a 2-in-3 probability over the next 50 years of a catastrophic levee failure in the massive delta region east of San Francisco.
"Local land decisions later result in cries for federal help. Does that make sense? No," Galloway said, adding that the federal flood program was "rudderless."
Nor do efforts to guard against floods automatically reduce risks, said Nicholas Pinter, a professor of geology at Southern Illinois University. Pinter said as much as 85 percent of the Mississippi in St. Louis is confined behind levees, which have raised flood levels 10 feet to 12 feet higher than they were just a century ago. That parallels the situation in New Orleans, which suffered catastrophic flooding when levees failed in the wake of Katrina.
Bolstering levees may lure more people onto flood plains, Mount said.
"You actually spur development. It's a self-fulfilling process," Mount said.
In the St. Louis area, there has been an estimated $2.2-billion in new construction on land that was underwater in the 1993 flood, Pinter said. New Orleans probably will not be immune to that same lack of foresight, he said.
Norbert Schwartz, director of the mitigation division of the Federal Emergency Management Agency's Chicago office, did not dispute that there has been a "substantial" amount of construction on lands abutting levees across the United States. But he said the national flood insurance program saves $100-billion in potential flood costs each year.
[Last modified February 19, 2006, 01:10:11]
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