The District 65 school board holds a public hearing next month on its tentative budget for the current school year that shows spending increasing twice as fast as revenue.
Overall operating fund revenue is expected to increase by 1 percent, while spending rises by 2 percent.
Despite that, the revenue is still expected to exceed expenditures — but by the smallest margin in several years.
The district gets about 75 percent of its operating revenue — or $67 million — from property taxes.
School officials say they expect enrollment levels to remain stable this year, followed by a gradual increase the next four years.
Rising costs are projected to lead to budget shortfalls by the 2012-13 school year.
Teacher salaries are projected to increase 3.7 percent this year.
The budget hearing will be held during the school board meeting on Sept. 22.
The budget and a presentation explaining it are available on the district website.
The school board gave tentative approval to the budget on a 6-0 vote at its meeting Monday night.