Prince William County adopted a budget Tuesday night that will raise taxes by 4.5 percent for the average household.

The budget funds most of the priorities that residents and county employees have spoken about repeatedly during weeks of hearings. These include two new libraries, park improvement projects across the county, increased support for nonprofit organizations and new hires for the police and fire departments.

The county’s tax rate will be $1.148 per $100 of assessed value, four cents lower than fiscal 2014. But because property assessments have risen, most households will pay higher property taxes. The nonbinding, five-year plan, which the county supervisors adopted at the same time they adopted the budget, calls for a 4 percent increase in the average tax bill in each of the successive four years. The plan forecasts that the county will need additional revenues to continue funding the two libraries, police hiring and an expansion to the crowded county jail.

The budget passed by a vote of 6 to 2 after discussions during which supervisors advocated both higher and lower tax rates.

Peter K. Candland (R-Gainesville), consistently the voice among the supervisors calling for spending cuts, had proposed a budget that would limit tax increases to 2.5 percent annually and cut as many as 200 unfilled county positions. He and Vice Chairman Michael May (R-Occoquan) voted against the final budget package, which was proposed by Chairman Corey A. Stewart (R-At Large).

Frank J. Principi (D-Woodbridge) was the only supervisor at Tuesday night’s final budget discussion to advocate for a higher tax rate, calling on supervisors to pick the highest rate that they could, the advertised tax rate of $1.158. He eventually voted for Stewart’s proposal and told Stewart, “You’re looking more and more like a Democrat every day,” which Stewart jokingly said he did not appreciate.

Before the supervisors voted, residents, many of whom had spoken to the board repeatedly during the budget process, lined up one last time to either ask for higher taxes to fund their pet projects or plea for lower bills.

Bill Hosp, president of the Prince William Federation of Teachers, asked that the board set the highest tax rate allowed so that the allotment for the school district would be as large as possible. “There are academic and safety concerns that go with having the largest class sizes in Virginia. Our schools need all the help they can get,” he said.

Several residents asked for funding for the two new libraries, which were approved in a 2006 bond referendum but have not been built. “The citizens in Prince William County told you in 2006 that they wanted these libraries. They waited eight years, and it’s time to move forward,” Mary Jo Rigby said. “That’s where our children learn to read.”

Others made ardent pitches for lower taxes. Bill Petrak, who had also spoken on the topic at earlier meetings, pointed out that six of the board’s eight members are Republicans and said that he was surprised that so many of them seemed willing to raise taxes.

“What happened to you folks? [Are] you a bunch of tax-and-spend liberals who fooled the electorate?” asked Petrak, a Woodbridge resident. “You folks are running these people out of the county, especially the senior citizens.”