Tuesday, June 17, 2008

Why flooding worsens in the US

A few snips from a solid piece in the Christian Science Monitor: ….In many communities, levees protect low-lying neighborhoods and farmland. “America has had a love affair with levees since the 1800s,” says Marceto Garcia, professor of civil and environmental engineering at the University of Illinois at Champaign-Urbana. But levees cause new problems by confining rivers and increasing flooding in other stretches.…Levees also leave some people with a false sense of security. In some cases, experts say, homeowners don’t know that their houses are at risk of flooding.

Experts also fault poor local planning. They say that economic and political pressures in many cases cause communities to slight flood-plain management for fear of hurting economic growth. In addition, they say, communities typically plan for present conditions without taking into account future growth and developments upstream that may create worse flooding – and worse damage – in the future.

“We have as a nation spent increasing amounts of money on preventing floods, and yet the cost of flooding continues to rise dramatically,” says Andrew Fahlund, vice president for conservation at American Rivers, an environmental advocacy group based in Washington. “Clearly we’re not doing something right. Certain kinds of flooding are going to be pretty much unavoidable. When water levels get to a certain point it’s pretty difficult to prevent damage. Our hearts go out to people who have been impacted by all this. The fact is that we have reduced the capacity our rivers have to absorb these floods significantly.”

Climate change has recently cast a new and disturbing uncertainty over flood-management questions by suggesting that history may be an unreliable guide to the future. Kenneth Potter, a civil and environmental engineer at the University of Wisconsin-Madison, says many scientists agree that climate change is likely to increase the occurrence and severity of storms as well as droughts, and thus increase the likelihood of flooding. “The question is, are you going to face that once a century or once every 10 years?” he asks….

Sandbags in New Orleans in preparation for flooding from Hurricane Katrina, FEMA, Wikimedia Commons

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