Mecklenburg County's stormwater officials are recommending a slight raise in monthly stormwater fees so the county can continue buying at-risk structures in flood-prone areas and pursue other methods to minimize flood threats.

Dave Canaan, the county's stormwater services director, told six of nine county commissioners Tuesday that the increase is necessary because federal FEMA money used for flood mitigation is drying up - as are houses in flood-prone areas eligible for the grants.

To replenish the lost FEMA money, Canaan asked that stormwater fees be raised by 39 cents a month for the greatest portion of residences, phased in 13-cent increments over three years. The increase would be sharper for larger houses and businesses.

The commissioners, meeting in a work session, won't take up the request until budget matters are voted on later this year.

Flooding has become a major issue in Mecklenburg after years of proliferating development. As more homes and shopping centers have been built and ground paved over, stormwater has fewer places to soak into ground.

So runoff turns to flooding.

During heavy rainstorms last August, the worst flooding in three years damaged 160 structures. After that, the county spent $2 million to buy more than a dozen homes.

Yet Canaan and Tim Trautman, the county's flood mitigation program manager, said the program in place since 2000 saved 100 houses from flooding during the August storm.

The past 12 years, Charlotte-Mecklenburg Stormwater Services has spent millions to buy and demolish 250 structures in flood-prone areas, Canaan told commissioners.

The county still has 4,000 structures in those areas - with 1,500 of them at risk because they have finished floors below protective flood levels.