Print

Email story

Comment

Email editor

Study of buildings, not land, changed flood map

By BILL VARIAN
Published January 19, 2006

TAMPA - It took four years for Hillsborough County planners to come up with new maps updating the areas most likely to flood in a really bad rainstorm.

And it took just three months after those maps were published - showing 24,000 new parcels in the high-risk zone - for planners to say about 6,000 homes didn't rank as high risk after all.

What happened?

Planners say it wasn't that the lines on their new maps were wrong. But they say they've spent days, nights and weekends in recent months figuring out whether those flood-prone parcels take in actual buildings, rather than just the land around them.

That's how they say they've managed to eliminate roughly 24 percent of the properties that were to get a high-risk label for flooding. The label will determine whether property owners who don't have flood insurance now are required to purchase it.

"The majority aren't disappearing (from the flood zone)," said Eugene Henry, hazard mitigation manager for the county's Planning and Growth Management Department. "We're able to say, in the urbanized areas where we have more data, we're able to say your property is in the zone but you're building is not."

Hillsborough County has spent the past few years doing the first wholesale update on its flood maps in more than two decades. The maps are meant to reflect changes in topography and development and were created with the aid of improved technology that enables more sophisticated projections of where water will pool and flow in heavy rains.

The result was that 24,000 land parcels in the county previously designated low risk got a high-risk label. For those property owners still paying off loans, the label means they likely will have to buy flood insurance policies.

The update was part of a $10-million effort to map the county's primary inland flood basins to better invest in public drainpipes and other flood-control measures.

[Last modified January 19, 2006, 01:48:21]