The cost of funding Montgomery County's public schools is expected to grow at the same rate as the county's revenue, about 2 percent each year for the next five years, stunting the growth of every other county agency unless lawmakers find other sources of money.

A report from the county's Office of Legislative Oversight, released Tuesday, pegged a recently tightened Maryland law that requires increased spending for higher enrollment, and the shift of teacher pension costs from the state to the county, as drivers of the schools' ballooning budget.

Essentially, the County Council was told that the security of the schools' funding was coming at the expense of every other county agency.

"The county government, parks and planning, and to some extent [Montgomery] College bear the entire risk," said Aron Trombka, senior legislative analyst in the Office of Legislative Oversight.

The state's "maintenance of effort" law requires each county to spend no less per student than it did in the previous school year. Montgomery's student population has surged by about 2,000 students each year for the past five years, prompting the county to increase spending, and similar enrollment trends are expected to continue. Currently, 52 percent of the county's budget goes to the school system.

In the past, the county has been able to ignore the funding law, receiving a penalty of fewer dollars from the state in the following fiscal year. But the law was strengthened this spring so that the state can redirect county tax revenue to the schools if the law's funding level isn't met. In other words, the county no longer has a choice.

Because of this enrollment trend, the annual county contribution to Montgomery County Public Schools likely would grow 1.8 percent each year. But as teachers' pension costs are shifted to the county from the state -- $27.2 million this year, which will increase to $44.4 million by fiscal 2016 -- that annual growth is more like 2.1 percent, nearly the same as the growth rate expected for county revenue.

Councilman George Leventhal, D-at large, said he was concerned about the schools' funding at a time when many health and human services programs were shortchanged: for instance, caseworkers who help families get access to food stamps.

"If children don't have access to adequate nutrition, they won't be able to learn. ... When all of our county government is restrained, those who suffer the most are the children in our school system," Leventhal said.

The council is scheduled to meet with the school board next week.