Sunday, May 22, 2011

Americans take a gamble with the Mississippi floods

Suzanne Goldenberg in the Guardian (UK) describes a deeply ingrained US tendency to ignore risk. Since preventing development in dangerous areas rarely has much standing on the nation's agenda, we keep making the same mistake for the sake of short-term gain: …Seen one way, the floods are an act of nature, beyond human control – and America got off relatively lightly. Despite extensive property damage, with predictions that more than a million acres of land would go underwater, only four deaths due to flooding have been recorded so far, in Arkansas and Mississippi. Industries, population centres and shipping in the Mississippi have been protected. Unlike in Hurricane Katrina, the Army Corps of Engineers, which is in charge of flood control, has had no levee failures.

Looked at another way, the flooding was entirely predictable. Damage to homes and fields in the Mississippi's way should have been avoidable. For all the effort over the years put into controlling the Mississippi, for many individuals – and even entire towns – there is only the illusion of safety.

…There is complacency and resignation. Flood experts argue that America's flood protection standards are lax compared with those in other countries. Authorities have hesitated to relocate people to safer ground, or to enforce laws that compel local authorities to provide flood protection and require homeowners to get flood insurance.

"We have been very good at letting people continue to live in harm's way," said George Galloway, who was commander of the Army Corps at Vicksburg in the 1970s. "But how much longer can we continue to do that since we know with climate change we are going to have more floods than in the past?" In the 1990s, Galloway led a White House study into improving flood protection. It concluded that most people living in flood areas – up to 7 million across the country – did not fully understand the risks they faced.

…It is becoming evident that the Army Corps of Engineers and other forecasters have underestimated the frequency of severe flooding along the Mississippi. "We had a 500-year flood in 1993, a 70-year flood in 2001, and a 200-year flood in 2008. What blows my mind is that I just published this paper in 2008 and every year since then we have had another 10-year flood," said Robert Criss, a hydrologist at Washington University in St Louis. "The observed frequency of flooding is completely incompatible with the Army Corps estimates."…

The Great Mississippi Flood of 1927, Greenville, Mississippi. The river stage was at 46.8 feet. From: "The Floods of 1927 in the Mississippi Basin", Frankenfeld, H.C., 1927 Monthly Weather Review Supplement No. 29.

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