The Olentangy Local School District is running out of room for its youngest students -- and the school board could vote as soon as next month to spend millions on expanding existing elementary schools.

The district faces increasingly "tight quarters" in its elementary schools as it continues to add hundreds of new students each year, said Superintendent Mark Raiff.

Board members May 17 heard a report from the facilities committee that recommends adding six-classroom expansions onto three elementary buildings. The specific buildings have not been determined.

Ideally, the 18 new classrooms would open in time for the 2019-20 school year, said Sharon Jurawitz, a committee member who briefed board members.

The additions are expected to cost about $3.4 million each.

Olentangy has about $14.9 million left from a 2011 bond issue that it could use to fund the additions, said Emily Hatfield, district treasurer.

"We've been predicting that this day was coming, and we're working hard to accommodate the growth in our elementary schools," Jurawitz said. "We opened Shanahan Preschool and we still need classrooms."

The facilities committee expects more than 1,700 students to enroll in Olentangy elementary schools over the next decade, Jurawitz said.

Housing starts in the district -- one of the best predictors of incoming students -- averaged 620 annually over the last five years. In 2017, there were 766, Jurawitz said.

The district predicts it will be completely out of space in its elementary schools by 2020-21.

"We're at the point where we cannot create any new classrooms. We're at the point where we will have to increase class size," said Jack Fette, chief academic officer.

At the elementary level, the district caps classes at an average of 24 students per teacher.

The district partially is a victim of its success; special-education services and its preschool are among two of the fastest-growing student populations, officials said. Those classes often have smaller student-teacher ratios, impacting staffing levels and the physical space needed to house students.

Jurawitz said sites were weighed for elements such as utility placement and property lines to determine schools that could be easily expanded. The preferred schools are Wyandot Run, Alum Creek, Arrowhead, Cheshire, Indian Springs, Scioto Ridge and Freedom Trail, according to the committee report.

The committee did not consider building-level enrollment, Jurawitz said.

"There's one elementary school that we've ruled out all together and that's Oak Creek," Jurawitz said.

The placement of utility lines, both above and below ground, would hinder construction at that school, she said.

Regardless of whether any schools are expanded, Jurawitz said the facilities committee projects the district will need to open its 16th elementary school in 2022. If growth continues at its current pace, Olentangy could need still another elementary school as early as 2026, she said.

There is no money for construction of a new building.

Building a new, 35-classroom elementary school is expected to cost between $18 million and $20 million, according to facilities committee projections.

Heritage Elementary School, which opened in 2011, is Olentangy's newest elementary school.

Raiff said the idea of adding onto existing buildings is "a new concept" for the district, but it could make financial sense.

"The numbers certainly show (the need) for additional classroom space, even beyond two new elementary schools," Raiff said. They will help avoid "raising class sizes to a level our community has not found acceptable."

The next school board meeting is scheduled for 6 p.m. June 14 at the district's headquarters, 7840 Graphics Way.