Gainesville City Schools officials may have to dip into the district’s reserve funds to balance a $70.4 million spending plan in fiscal 2018 that is 3.4 percent more than the current budget. Driving up the cost of educating about 8,500 students in the system are an increase in staffing from the opening of the new Mundy Mill Academy elementary school opening this fall, state-mandated higher contributions to the teacher retirement system and increases in providing health insurance to classified employees. The school board is scheduled to review a tentative budget at its meeting May 15.