Every Few Years, Another 100-Year Storm
Hurricane flooding along Alabama's coast regularly surpasses federal 100-year storm predictions, with frightening implications for the future. Originally published in the June 9, 2007, Mobile Press-Register, this article tells how residents were misinformed by official federal flood predictions, and left to fend for themselves.
Image: In the Danger Zone
Steve Myers

The risk of flooding didn't deter James and Sandy Jarrett from buying a home on Fowl River. But 100-year storms came twice in 11 months, along with a lesser storm that also ruined everything. Their new home on the river is well above the flood plain.

James and Sandy Jarrett knew that their Fowl River home sat below the federal government's predicted 100-year flood level, so they bought flood insurance and figured they'd get wet —once every 100 years.

"I had no idea we'd lose everything three times in 11 months," Sandy Jarrett said.

The federal flood map puts a 1-in-100 annual chance on a hurricane or rainstorm pushing Fowl River over its banks until it climbs 8 feet above sea level, enough to send 2.5 feet of water inside the Jarrett home.

Instead, within one year, the river reached or exceeded 8 feet during Hurricane Katrina and an April 2005 rainstorm, and almost hit 6 feet during Hurricane Ivan. Each time, the Jarretts got soaked.

They may have been unlucky, but they were clearly misinformed, according to a Press-Register analysis. The newspaper's research suggests that government flood maps underestimate coastal flooding throughout Mobile and Baldwin counties, in large measure because the federal government's definition of a 100-year storm appears to have little basis in reality.

Predicting what a 100-year storm would look like can be a complicated process. Scientists study the impacts of past storms and make statistical calculations that predict how common such storms have been.

But Press-Register research indicates that federal flood predictions don't take into account some of the Gulf Coast's most significant storms.

The net result is that so-called 100-year storms are occurring several times a century in Alabama, flooding some people over and over.

Outdated flood maps have led entire communities to build homes to standards more than two decades old.

The newspaper compiled government high-water marks from hurricanes spanning 36 years —1969 to 2005 —and compared them to current federal maps of local flood zones. The comparison showed that along the Alabama coast, hurricanes have pushed water above and beyond the 100-year flood plain repeatedly.

Due to poor mapping, creaky science and outdated data, federal flood maps simply don't appear to reflect the reality of flooding in both counties.

The deficiencies in Alabama are similar to those exposed in coastal Mississippi, where Katrina destroyed thousands of homes built too low, including many that were uninsured for flooding.

The Federal Emergency Management Agency is in charge of the flood maps and is redrawing them for Mississippi and Louisiana. Alabama's maps have not been addressed in the same way. FEMA officials pledge to take the same steps here, although it's not clear when such maps will be ready.

Few homeowners ever look at a FEMA flood map, but those documents influence where they build their homes, how they construct them and how much they pay for insurance.

Mortgage companies require all homes within the 100-year flood plain to be covered by the National Flood Insurance Program, which FEMA runs. And homes near open water must be elevated above storm surges and constructed to withstand the pounding of waves.

Inaccurate maps can influence people to forego flood insurance, either because they don't believe they're vulnerable or because their lender doesn't require it. Although the federal government urges everyone at risk to buy flood coverage, numerous interviews suggest that people make their decisions based on the official 100-year flood zones, regardless of the actual history of flooding in the area.

Outdated flood maps have led entire communities to build homes to standards more than two decades old. Back then, Camille was the most destructive storm to hit the coast, but was widely assumed to be an extraordinarily rare event. Thus the 100-year flood predictions developed after Camille didn't require builders to plan for a similar surge.

Likewise, the federal government considered Hurricane Frederic, which struck Dauphin Island in 1979, worse than a 100-year storm, so flood predictions were not raised to match that storm's surge.

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