With sales-tax increases planned for the November ballot in both Petaluma and the county, government leaders on both sides say they hope they can persuade south county voters to support a total 1¼-cent increase in their tax rate.

Petaluma intends to ask voters to approve a 1-cent permanent sales-tax hike that the City Council has said it would use to pay for police staffing, police and fire buildings, road repairs and traffic relief.

The Sonoma County Board of Supervisors is set to formally vote Tuesday to put its own quarter-cent tax increase on the ballot countywide, in conjunction with an advisory measure asking voters if they agree that roads are a priority.

While both bodies have said they intend to use the money primarily for roads, the ballot measures are written as general sales tax increases, which need only a 50 percent plus one majority to pass.

A specific tax — locked in for spending only on a particular purpose — needs the more challenging two-thirds majority for approval.

Petaluma rocked the boat two weeks ago when it unanimously passed a “resolution of nonsupport” opposing the county sales tax measure, arguing, among other reasons, that it could damage voter support for Petaluma’s local tax increase.

City leaders also expressed discomfort with the idea that city voters are being asked to subsidize little-used county roads at the expense of regional traffic needs like Highway 101 through Petaluma.

The move of public nonsupport for another agency’s plans was unexpected for county leaders.

“It was a little surprising and also disappointing,” said Supervisor David Rabbitt, who represents the 2nd District, which includes Petaluma.

He said Petaluma leaders knew the county had been considering its own sales tax increase and knew the formula the county plans to use to disburse proceeds to each city if the county measure passes.

He called the city’s lack of support for the county tax increase “too myopic.”

“The county is looking at the broader issues,” he said. “It’s a modest, quarter-cent increase. … Petaluma’s roads are in poor shape, as are the county’s. We have to figure this out together.”

Petaluma would receive about 9.5 percent of the proceeds, although as a city it accounts for 14 percent of the county’s sales tax income.

That amounts to about $2 million a year for Petaluma, if the county tax passes.

“You would think that getting close to $2 million a year for pavement improvements — that’s up to 10 miles a year — for them to say, ‘No, thank you, we don’t want to go down that road,’ is disappointing,” Rabbitt said.

City Manager John Brown said he hasn’t heard of any further efforts for the city to oppose the county’s tax measure this election season.

“The city felt its needs were best served by not having a county measure,” he said.

“As we move forward, that will have to be part of the campaign strategy — if we address that or how we address that issue of a competing measure, or if we can cooperate and collaborate and both achieve what we want without hurting each other’s chances.”

Polling conducted in Petaluma showed support of less than 10 percent from city voters if both a city and county tax increase were on the November ballot.

But county officials say their polling shows overall support of about 68 percent for their measure.

“I’m sure that they’re worried that we’re going to somehow submarine their measure,” Rabbitt said. “I don’t think that is the case.”

Councilman Mike Harris said the county measure may be “doomed” if Petaluma voters oppose it in those numbers.

Petaluma leaders will focus on the idea that proceeds from a city tax increase — expected to be about $10 million a year — would stay local and be spent on local priorities. City officials have said in addition to road and sidewalk repairs, the money would be spent to hire several new Police Department employees, build new fire and police buildings and buy new public safety vehicles.

County officials will have to convince city residents that their tax dollars are also needed to fix roads that lead in and out of cities, not just country lanes used by a handful of residents.

“Roads are the one thing that touches every resident every single day, literally,” Rabbitt said.

“We have a long-term plan that is affordable and attainable. We’ve been talking about this issue long enough. We can grasp the initiative and make it happen now. I think that would be a great thing to do for future generations.”

You can reach Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com. On Twitter @loriacarter.