Fluoride could flow from city taps within a year.

The city’s nearly 3-year-old fight to keep the chemical out of its water supply may have come to an end Wednesday when an appeals court ruled a state fluoridation law trumps local voters.

The ruling by the Sixth District Court of Appeals sets a precedent for cities statewide, though the Watsonville City Council could decide to take its defense of the 2002 voter-approved Measure S to the state Supreme Court.

“They should save their money and just go ahead and fluoridate the water supply,” said Jim Jacobson, a Watsonville orthodontist and president of Dientes Community Dental Clinic. “The need for community water fluoridation is incredibly great.”

Fluoride helps prevent tooth decay, and introducing the chemical into water supplies makes its benefits available to entire communities, backers say. That’s particularly important in cities like Watsonville, where large low-income populations might not get dental care.

But opponents question the chemical’s safety, and don’t believe the state has a right to force a medical treatment on people through the public water supply.

“The state has the right to regulate the potability and quality of water so we have clean, clear drinking water,” said city attorney Alan Smith. “No one disagrees with that, but fluoridation is one step forward.”

But the panel of three judges on the appeals court in San Jose upheld the state law, which mandates fluoridation in cities with 10,000 or more water hookups if funding is available.

The California Dental Association Foundation had offered the city $1 million to install a fluoridation system and operate it for one year. The foundation’s president, Jon Roth, hailed the court decision and said the organization likely will extend the offer again.

City Manager Carlos Palacios said city water could be fluoridated within a year, unless the council decides to take the case to the state Supreme Court.

Smith said the council has until early December to decide.

Nick Bulaich, who spearheaded the successful campaign for Measure S, said he hopes city officials will continue to fight. The people pushing fluoridation are outsiders like Roth, he said.

“I am not going to be the one to abandon the vote of the people,” Bulaich said.