TAMPA - A split planning commission took the first step Monday night toward wider protective buffers around Hillsborough County's wetlands.

Supporters say 50-foot setbacks instead of 30-foot will protect wetlands and waterways from pollution and improve drainage. Some developers say it's an expensive intrusion on private property rights.

On a 5-3 vote, the commission approved an amendment to the county's comprehensive growth plan. The increase still faces major pitfalls. The planning commission action is only a recommendation; the county commission makes the final decision.

Also, the policy the planning commission approved involves forming a technical advisory committee to make recommendations on both the 50-foot setback and a manual to provide guidance for site-specific setbacks.

That means, even with county commission approval, the technical committee could delay or block the larger setback.

"At least this gets us to the next step," said Vivian Bacca, a Brandon homeowner who supports the wider setbacks.

At least 50 people rose to show the commission they supported the change. Most wore green and yellow badges that said: "Protect My Land and Water. Setback 50."

Denise Layne, an environmental and growth management activist from Lutz, said the county has $23.9 million worth of stormwater improvements planned through 2011. Many of those improvements are necessary, Layne said, because development has destroyed wetlands and fractured hydrological systems connecting lakes, streams and groundwater.

"Our taxpayer dollars have paid for the destruction of wetlands and waterways," Layne said. "We must stop it. We can't afford it."

Opponents, mostly developers and consultants to developers, said the wider buffers would be unjust and too expensive.

Michael Peterson, a developer in southern Hillsborough, said county regulators often classify a 10-foot-wide, man-made ditch as a wetland. Peterson said putting a 50-foot buffer on either side of the ditch could take as much as 11,000 square feet away from the property owner.

"A thousand square feet of wetlands suddenly become 11,000 square feet taken," Peterson said. "And if you don't believe that happens, I can show you some."

Planning Commissioner Edward Giunta, as he has in the past, criticized the county Environmental Protection Commission for not presenting scientific evidence that shows wider buffers are needed.

"What our policy says is show us studies that support increasing the buffers," Giunta said.

Gerold Morrison, EPC environmental resource manager, said the agency was not given time or funding to perform studies locally. Morrison instead provided the commission with research from Chesapeake Bay, where setbacks of at least 50 feet are used to clean up the polluted water body.

Morrison also cited recommendations by the Florida Department of Environmental Protection and state Department of Agriculture and Consumer Services that farmers use 55-foot buffers to prevent fertilizers and pesticides from polluting waterways.

The wider buffer proposal will be heard by the county commission April 19.

Reporter Mike Salinero can be reached at (813) 259-8303 or msalinero@tampatrib.com.