BRUNSWICK – The future closure of the Brunswick Naval Air Station could result in a 20 percent decline in school enrollment and the loss of hundreds of thousands of dollars in school funding, officials said.

More than half of the 450 elementary pupils at Coffin School are Navy kids, who typically stay in Brunswick for a few years before their parents move on to another base. Meanwhile, other military families move into town to take their place.

But when the military families stop coming, enrollment, funding and school life in general will change.

Everything in the school system, from its nearly $30 million budget to its recently approved plan for a new elementary school, will likely take a hit, school officials said.

With no military children, the school system won’t be eligible for the $700,000 to $1 million it gets annually from the federal government. The funding will disappear slowly as the pupils move away.

With 20 percent fewer pupils, state aid also will drop. The education commissioner plans to introduce a bill at the next state legislative session to ease that loss for Brunswick and other towns that deal with a sudden dip in enrollment.

School officials are hopeful that new families with children will move into Brunswick, leaving higher-priced southern Maine towns for more affordable housing.

“I see those houses filling very quickly,” said Walter Wallace, principal of Coffin School.

An enrollment decline also would jeopardize a plan to refurbish or replace the old Hawthorne School, a 110-pupil elementary school that recently won the last spot on the state’s school construction list, meaning Brunswick is set to get state money for repairs or a new school.

State officials will talk with school officials about their options. But Superintendent James Ashe still plans to push for the new school, believing that the base closure isn’t enough to ease overcrowding.

“If all the military kids left tomorrow, I’d still have space needs,” he said.

The school system has no single, concrete plan yet for dealing with the loss of pupils, volunteers and money. The base closure process won’t begin for two or three years and will be complete in five or six years.