Up to 29,000 Arizonans paid for insurance under the National Flood Insurance Program in fiscal year 2004, but new research shows that many may not need the costly coverage.

A study headed by a University of Arizona associate professor suggested the risk of flooding in Arizona is not as severe as projected by the estimates provided by the Federal Emergency Management Agency.

Currently, the National Flood Insurance Program requires all residents to buy flood insurance in land declared a high flood zone.

But according to the UA research, only 5 percent of the damage predicted by the FEMA agency is likely.

“Current flood-plain maps have a financial impact on Arizona for sure, because people and communities are paying for flood insurance they won’t realistically use.” said Jon Pelletier, a UA associate professor.

Pelletier said Arizonans who don’t need the federal flood insurance are subsidizing other parts of the country and are paying for reconstruction costs in areas that are really flood-prone, like the Mississippi flood plain.

For large-scale developments there are already engineering and updated risk-assessment methods in place that are pretty accurate. But for owners of older homes and for new homes that are not part of a larger development, updated flood information is extremely important, said Philip Pearthree, a geologist for the Arizona Geological Survey.

Updating outdated flood-plain information can take FEMA years.

Real estate officials said flood-plain mapping should be revised to reflect up-to-date, more accurate scientific data, which could potentially save homeowners hundreds of dollars a year.

Pelletier’s team, which included Pearthree, studied the foothills of the Harquahala Piedmont west of Phoenix and the Tortolita Piedmont northwest of Tucson using remote sensing, geological mapping and a numerical computer model.