TAMPA - Here on the Hillsborough River, the tannin-stained water flows languidly past a mishmash of houses, apartment buildings and the occasional restaurant or marina.

Beyond the tranquil setting, though, a battle is brewing over future development along the river.

The city wants to create a 30-foot buffer zone from the water's edge. The plan, set to be considered by Tampa City Council today, would cover a more than 10-mile stretch along both sides of the river, from the Columbus Drive Bridge to Temple Terrace.

If approved, the changes could affect hundreds of riverfront property owners, from current residents who want to install a pool or deck near the water's edge to developers who want to build a new house or a multiunit subdivision.

City officials say the restrictions would protect the river from pollution by lawn fertilizer and pesticides and bring much-needed conformity to the patchwork of development along the river.

For many home and property owners, though, the changes amount to an assault on their property rights.

"We're talking about thousands of homeowners who could be told by the government that they can't build a new pool or deck near the river," said resident Anthony Pita, who lives on the river. "That's just not fair."

Pita said members of his Riverside Heights Homeowners' Association are gearing up to fight the proposal.

"People don't seem to understand how much this will affect them," he said.

Councilwoman Linda Saul-Sena, who proposed the changes, said the river needs additional protection. She asked the city's zoning department to look into expanding the setbacks after travelling the river on a recent boat tour with environmentalists.

"The quality of the Hillsborough River is an important resource for our community," the councilwoman said. "We need to protect and maintain that resource or we'll lose it."

Setbacks for waterfront lots and other structures now range from 5 to 20 feet.

"There are houses that have been built right up to the river's edge," Saul-Sena said.

Among the changes to be considered:

•Create a 30-foot waterfront lot setback for residential development;

•Increase the required setback for accessory structures such as sheds and additions from 15 to 30 feet;

•Increase pool and deck setbacks on the river from 5 to 15 feet;

•Require that pools, decks and other structures not exceed 30 percent of the waterfront yard area.

Environmental groups back the changes because they say expanding the buffer zone will prevent further encroachment from residential development along the waterway.

"Everyone's backyard is a potential source of pollution into the river," said Phil Compton of the conservation groups Friends of the River and Sierra Club. "The river is rebounding, and fish and birds are returning. We need safeguards in place to ensure that continues."

Today's discussion on the setbacks is at a council workshop where no vote will be taken. The proposed changes are in a series of amendments set to be considered by the council next month. If approved after two public hearings, the changes wouldn't take effect until Jan. 1.

Existing structures would be grandfathered in. Property owners will be able to request a variance, but must prove the new regulations have created a hardship on them.

This isn't the first time that city officials have tried to change the riverfront setbacks.

In 1998, then-Mayor Dick Greco ignited a firestorm when he proposed reducing setbacks in the section of the river that runs through downtown to attract waterfront investment.

Greco's proposal was eventually scrapped in favor of a council-approved plan requiring developers to apply for a setback variance if they wanted to build along the river.

Councilman Charlie Miranda said he would not support changes that deprive riverfront homeowners of the right to develop their land. He expects a "big debate" on the issue.

"People are worried," he said. "They don't want big government telling them what to do."

Reporter Christian M. Wade can be reached at (813) 259-7679 or cwade@tampatrib.com.