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Katrina + 1: Are we rebuilding in harm's way?

POSTED 24 AUGUST 2006

Gulf Coast rebuilds
If ever a year screamed for smarter land-use planning in the flood zone, it was 2005: Between the Indian Ocean tsunami on Dec. 26, 2004, Bulldozers at work in dirt pushed every which way.and Katrina's Aug. 29, 2005 assault on the Gulf Coast, it was hard to ignore the aqueous corollary of real-estate's number one maxim: location, location, location. All by its lonesome, Katrina accounted for the largest single loss in the history of insurance, says the Insurance Information Institute $40.6 billion, plus another $15.3 billion to the federal flood insurance program.

Getting ready for some serious construction in the Mississippi River floodplain, near St. Louis. This ground was under water during the 1993 flood. How long will the new levee hold? Will it block the river and raise floods upstream? Photo: ©David Tenenbaum

If you build in the path of moving water, sooner or later, water will win.

To put it in dollars and sense: The Insurance Information Institute also says seven of the 10 most expensive hurricanes in history occurred in 2004 and 2005. In the North Atlantic (including the Gulf Coast) the record losses of 2004 were immediately dwarfed by the losses in 2005.

Graph indicates that over 160 million dollars was lost due to hurricane damage in 2005.
Overall losses from hurricanes - in millions of U.S. dollars -- have been soaring over the past few years. Data from "Hurricanes - More Intense, More Frequent, More Expensive," Munich Re, 2006. Also see Insurance in a Climate...

So how we doin'? The Mississippi Coast has made its decisions, and construction is proceeding, based on the new reading of the possible height of a storm surge (the mound of water pushed up by a hurricane). Katrina has added three to eight feet to the previous estimate of 11 to 12 feet above sea level, says Larry Larson, executive director of the Association of State Floodplain Managers.

The requirement for greater building elevation will help protect against storm surges, but will also favor the rich. "The private sector is rebuilding [in Mississippi], developers are in there hand over fist," says Larson. "Biloxi was called the workingman's Riviera" because the coastal strip was populated by "$150,000 bungalows." Elevation is relatively cheaper for large houses, he notes, "So we probably will see a great demographic change. It will probably go to condos and million dollar houses for people who can afford to do the elevation."

New Orleans, whose land is sinking every year as sediments under the city compact, is still debating difficult decisions on where to rebuild. "The New Orleans situation will be different," says Larson. "It's terribly in limbo, the city isn't providing much leadership in terms of which neighborhoods it will provide services to. Really, New Orleans is much further behind. Their theory is, 'give us a good levee, and we can build more slab-on-grade housing.'"

Area outlined in red near central CaliforniaThat may be cheap, but Katrina also proved that failing levees put houses in the path of floods.

Breaks in the vast levee system around Sacramento, Cal. could flood thousands of homes, and cut off fresh water to millions in Central and Southern California. See movie. Image: State of California

Sacramento sacrament
Building in the floodplain is not just a problem on the hurricane coasts: Inland floodplains can also have their building booms. In the Sacramento (Calif.) Delta, where the Sacramento and San Joaquin rivers empty into a vast wetland adjacent to San Francisco Bay, developers hope to build 130,000 houses on land that is "protected" by storm-battered, poorly designed levees. In the Delta, says Jeffrey Mount of the University of California at Davis, "We are reinventing Katrina."

The Delta, Mount added, "is now bounded by 1,100 miles of levees... and it is subsiding much more than New Orleans. It's spectacular, it's 20 feet below sea level." Instead of hurricanes, the area gets earthquakes. A major levee failure could harm much of the state, because the Delta supplies much of the south with fresh water, Mount says. "Changes in hydrology, sea level, and seismicity can undo the system in heartbeat. In California, we have two kinds of levees: Those that have failed, and those that will fail."

Levees can be a false comfort, adds Larson of the floodplain managers association. "Levees change land that is subject to flooding into land that is subject to occasional flooding."

St. Louis blues

(St. Louis Blues, with apologies to W.C. Handy)
I hate to see that river levee built,
I hate to see that river levee built,
'Cause that river, it's gonna flood this town,
May drown tomorrow but I'm dry today,
If they build this levee an' my town does flood,
I'll pack my boat and make my get-a-way.

New buildings built in a sea of grass and swamp.
An up-scale development in the floodplain upstream from St. Louis, where the Mississippi, Missouri and Illinois Rivers meet. Will this instant neighborhood still look so homey when the next big flood rolls through? Photo: ©David Tenenbaum

Near St. Louis, we found another example of inland floodplain development: a new office park being built on 1,600 acres behind a new, four-mile, 25-foot levee in the city of St. Peters. The levee will "protect" the new development, local politicians claim, against a 500-year flood (a flood that supposedly has a 1 in 500 chance of occurring in any given year). But calculations of "X -year floods" are uncertain at best. Katrina, for example, was the third "100-year" storm to hit New Orleans in half a century. Around St. Louis, flood records are too short to define a 500-year flood. And drastic changes to the watershed and river basin impair the accuracy of those records that do exist, as we'll see.

Map shows snaking Mississippi River and new and old levees
Ongoing levee projects are radically narrowing the floodplain north of St. Louis. The flood of 1993 showed that such constrictions raise flood levels upstream. Courtesy Nicholas Pinter, Southern Illinois University.

At the Mississippi-Missouri confluence, a conservation group called the Great Rivers Habitat Alliance is fighting to preserve a large bottomland in the 100-year floodplain in St. Charles County. In Feb., 2006, Adolphus Busch, the group's chair, told the American Association for the Advancement of Science that after 1993, "there was little if any development and a large number of buyouts [to remove floodplains from development] by federal, local, state government. But by 1997-98, we saw wholesale development again going on."

Government is not just permitting but promoting development, said Busch, a scion of the beer family and hunter who lost his lowland home in the 1993 flood. "TIF [tax-incremental financing] is an enormous issue in this type of development. Developers want to use it to develop floodplains, saying they are an economic liability because they flood." TIF laws were written to defer property taxes and thus subsidize development in "blighted" areas.

As Busch mentioned, after the 1993 disaster, FEMA and other government agencies set out to "mitigate" flood hazards by buying up land. Eventually, these measures removed 35,000 structures, mostly houses, from the nation's floodplains. "That sounds like a lot," says Larson, "but there are about 11 million structures in the nation's floodplains."

Seen from above, the Mississippi River swells in times of flood
The Mississippi-Missouri-Illinois confluence, during normal weather (left) and the flood of 1993. New levees will narrow the river, making the next flood that much higher. Courtesy Nicholas Pinter, Southern Illinois University.

Many flood experts say that over time, the lessons of past floods get downgraded in favor of business-as-usual. "We have the opportunity to avoid risk," Pinter says, "but the lesson from St. Louis is that it hasn't happened." By 2005, he calculated, "$2.2 billion worth of new construction was taking place on land that was submerged in 1993" (see "One Step Forward..." in the bibliography). He warns that the development around St Louis over the past decade anticipates the future of New Orleans: a pattern of building in harm's way.

Historically, the insurance companies have promoted seat belts, smoke detectors and other common-sense safety measures. Can they slow the rush to build in harm's way?

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Megan Anderson, project assistant; Terry Devitt, editor; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive

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