MARLBOROUGH - The cost of rising debt service is driving much of the nearly 5 percent increase in the fiscal '17 budget Mayor Arthur Vigeant recently filed.

Vigeant submitted his proposed $149.8 million fiscal 2017 spending plan to the City Council Thursday afternoon. Last year, the City Council approved a $142.7 million budget.

Debt service is slated to rise by $5.6 million this year to pay for a handful of major projects, including upgrades to the easterly and westerly wastewater treatment plants, Millham Water Treatment Plant and the recently completed renovation of Assabet Valley Regional Technical High School.

"The main driver of the increase this year is the payments on debt service which has been anticipated for a number of years," Vigeant wrote in his budget filing. "Because of the increased debt service for this fiscal year, I have directed my city department heads to minimize budget increases."

The school administration anticipated a tight budget year and recommended a $60.7 million level services budget, which is a 1 percent increase from the fiscal 2016 budget. The district negotiated lower increases with the unions in fiscal 2017 knowing it would be a difficult budget year.

A handful of new staff members were added, but they are being paid for with one-time funding sources, including grants, or reductions from other areas of the budget.

"I want to thank my colleagues on the School Committee and the school administration for understanding the city's financial constraints this year," Vigeant wrote.

With continued commercial growth in the city, Vigeant said it will be necessary to make further investments in public safety.

"Although not included in my budget recommendation, as the year progresses and the financial picture becomes clearer for the upcoming year I hope to start looking at adding personnel to ensure that the police department has the officers it needs to keep Marlborough safe," Vigeant wrote.

At the fire department, new fire prevention and training officer positions are being proposed. Vigeant said those positions can be paid for from the department's existing budget.

To help accommodate the increasing membership at the senior center, Vigeant is proposing to turn the program coordinator position into full-time role. Since the new center opened last March, membership in programs has increased by about 1,000 people. The program coordinator plans and implements new programs, day trips, special events and the newsletter, the mayor said.

The proposed budget also includes a 6 percent increase in health insurance costs in fiscal 2017. The city's cost for water from the Massachusetts Water Resources Authority is also up 9 percent this year due to increased MWRA costs, chemical costs and increased testing frequency as mandated by the state Department of Environmental Protection, said Vigeant.

The Finance Committee is slated to begin its budget hearings and discussion this week. A public hearing on the budget is slated for the City Council's May 23 meeting.

Jeff Malachowski can be reached at 508-490-7466 or jmalachowski@wickedlocal.com. Follow him on Twitter @JmalachowskiMW.