Two contentious special district races are the centerpieces of Tuesday's election in Sonoma County, in an otherwise quiet off-year contest that includes no countywide campaigns.

A ballot measure crucial to Rohnert Park's fiscal future is at the polls, too. It would continue indefinitely a half-cent city sales tax that voters approved in 2010. Measure A has progressed through the campaign season with very little fanfare.

Two school district elections are also being held at opposite ends of Sonoma County, in Point Arena and Tomales Bay.

The special district races have generated by far the most heat.

The Graton Community Services District, which runs the rural west Sonoma County sewer system, has two board seats in play in what is the first election in its 10-year history.

Following a grand jury report that said the district's five-member board didn't have a good handle on its finances, HolLynn D'Lil and Richard Coleman stepped forward to challenge incumbents John Roehl and Jane Eagle, who maintain many problems have been fixed.

Bodega Bay's Fire Protection District, facing a severe financial crisis, has three board seats being contested amid charges that the incumbent board has responded inadequately to the budget problems. Constance Clover, Charlie Bone and Dave Kruppa are challenging Maggie Briare, Tony Anello and Barbara McElhiney.

Both districts have fewer than 1,000 registered voters — which has perhaps amplified the volume of their respective contests.

"These smaller districts, they're very intimate, everybody tends to know the board members, the opponents, and everybody's interested," said Brian Sobel, a Petaluma-based political consultant.

The Graton campaign especially took a nasty turn with allegations being traded of vandalism and illegal campaigning and emotions spilling over at community forums.

At stake potentially is control of the district's new $11.5 million wastewater treatment plant. Challengers D'Lil and Coleman have said they want to explore hiring a staff manager for the plant. That could displace the current general manager, Santa Rosa Junior College instructor Bob Rawson, who runs the plant as a contractor for $70 an hour.

The Graton services district has 795 registered voters and 550 houses that are served by the treatment plant. Of 539 mail ballots, 201 have been returned.

"Ithink you get closer to a 50 percent turnout in these smaller districts because people just know who all these people are and are familiar with the issues," Sobel said.

In Rohnert Park, though, where there has been no discernible opposition to Measure A, 4,484 out of 12,116 mail ballots have been returned, according to the Sonoma County Registrar of Voters, probably indicating a lower turnout Tuesday, Sobel said,

He said he thinks that's because the sales tax is in place already and there is nothing else on the city ballot to draw voters out.

"It's a stand-alone issue and nothing other than that issue compels people to vote," he said.

The Rohnert Park tax raises about $3 million annually for the city's general fund. City leaders have said if they don't get it extended they will have to look at cutting services. The tax was originally supposed to end in 2015.

Two seats are open on the Shoreline Unified School District Board. Incumbents Timothy Kehoe and James Lino are running and Avito Miranda is challenging for a seat.

In the Point Arena Joint Union High and Arena Union School District governing board election, four seats are to be filled.

There are five candidates: Cindy Cione; Robert Shimon, an incumbent who was appointed; incumbents Angela Marquez and Leslie Taylor Bates; M. Vikki Robinson and Suzanne Rush.

You can reach Staff Writer Jeremy Hay at 521-5212 or jeremy.hay@pressdemocrat.com.