PORTLAND – An unexpected spike in enrollment at the new Ocean Avenue Elementary School has swelled class sizes to maximum capacity and forced administrators to reassign teachers from other schools.

Officials had planned to welcome 375 to 390 students when school started earlier this month. By the end of last week, 438 had enrolled, according to data provided by the district.

The new school, which replaced Clifford Elementary School, was built for a maximum of 440 students, but that number exceeds class-size guidelines set by the district to ensure an optimum learning environment, said Principal Beverly Coursey.

The unexpected increase — much of it from last-minute kindergarten signups — has exposed problems with the district’s enrollment process and forced school officials to re-examine the neighborhood boundaries for its elementary schools.

“Everybody had their own theory on how many students we’d get, but we surpassed everyone’s theory,” Coursey said. “All of our classrooms are full and staffed with teachers.”

Because every available classroom is being used, school officials are talking about adding four classrooms in a second-floor area of the school that was designed to accommodate an expansion, Coursey said. That would be a long-term fix.

The new school opened in February — several months ahead of schedule — with 315 students who came from Clifford, Coursey said. It was built on the site of the former Baxter Elementary School.

When the school year started this month, Ocean Avenue Elementary welcomed additional students from the former Baxter neighborhood who had been attending Presumpscot, Longfellow and Riverton elementary schools.

Last spring and through the summer, the district surveyed parents in the former Baxter neighborhood to learn whether their children planned to switch to the new school or continue attending one of the other elementary schools. All kindergarten students in the former Clifford and Baxter neighborhoods were expected to attend the new school.

“We called, we wrote letters and we held public meetings,” said Superintendent Jim Morse. “We did all the right things to predict Ocean Avenue’s enrollment.”

By the first week in August, the new school’s enrollment was expected to be 390 to 400, Morse said. Then, during the last three weeks of August, an additional 250 students enrolled across the district, including about 50 at Ocean Avenue Elementary.

In the other elementary schools, enrollment has remained stable or dropped slightly, though not enough to provide wiggle room in the district’s already crowded schools, Morse said.

“Every building is bursting at the seams, except Riverton,” Morse said. Its enrollment is down about 80 students, from 452 in October 2010 to 368 last week, largely because of the shift to the new school, Morse said.

At Ocean Avenue, most classes are at the recommended levels of 18 to 22 students, but they’re particularly large in the fourth grade, which has about 25 students per class, Coursey said.

Administrators expected about 80 kindergartners but got 95, and expected about 60 fourth-graders but got 75, Coursey said.

In May, the district hired two additional second-grade teachers and additional third-, fourth- and fifth-grade teachers in anticipation of students from the former Baxter neighborhood.

Just before school started, the district reassigned a kindergarten teacher and a K-1 teacher to the new school from other Portland schools, Coursey said. They’re teaching in classrooms that were supposed to be used for special education programs and instruction of immigrant students who are learning to speak English.

“We’ve filled every available space with a core classroom,” said David Galin, the district’s chief academic officer. “We’ve reassigned teachers, so we haven’t exceeded budgeted costs.”

Still, the four kindergarten classes average 22 students — more than the 16 to 20 recommended in district guidelines, Coursey said.

The higher numbers trouble Marnie Morrione, a parent who serves on the school board and its facilities subcommittee.

“Our goal has been to reduce class sizes, especially in the elementary schools,” Morrione said.

The school board will look for ways to reduce class sizes and improve the enrollment process, she said. School neighborhood boundaries may be adjusted to relieve some of the pressure on Ocean Avenue Elementary.

As the school year goes on, some of the enrollment issues at the new school may work themselves out, Morrione said, but school officials must find a way to limit last-minute enrollments.

“It created a lot of angst for parents and schools across the district,” she said.

Staff Writer Kelley Bouchard can be contacted at 791-6328 or at: [email protected]