The number of school-age children in Groton declined 20.5 percent during the last 15 years, but the population is expected to level off in the future, census data shows.

Between 2010 and 2015, Connecticut's population of school-aged children decreased by 3.46 percent, the sixth highest rate in the nation, according to data from the U.S. Census. By 2025, the student population is projected to decline by nearly 10 percent to 631,241 students, according to the Connecticut State Data Center. Experts link decreasing student enrollment to a variety of factors, from a decline in the state’s birth rate, as people have fewer children and have them later, to people leaving the state for job opportunities.

As districts in southeastern Connecticut compete for students, the school-age population in the region is contracting. Census data shows the number of school-age children will drop 21.5 percent in southeastern Connecticut between 2000 and 2025.

But the timing of that decline differs by community. Groton shows a steeper decline of 27 percent than the region as a whole over that time frame. But data also show most of the population losses have already occurred.

“You see suburban communities continue to have a decrease in child population and in the urban areas you’re seeing an increase. So Groton, both being suburban and urban, we are seeing a very small decrease in the population,” Groton Superintendent Michael Graner said.

The number of school age children living in Groton fell from 7,932 in 2000 to 6,306 in 2015, or about 20.5 percent.

The population stabilizes in future years. The number drops 6.5 percent from 2015 to 2020, then 1.8 percent from 2020 to 2025.

By comparison, other nearby communities expect their steepest declines to occur in the future. Census data projects a 23.5 percent drop in the number of school-age children in Waterford from 2015 until 2025, an almost 24.5 percent drop in Ledyard, and a 27 percent fall in East Lyme.

Groton closed four schools in the last decade – the district previously had 14 schools and now has 10. A proposed new school construction plan would shrink the district further, from 10 schools to eight. The plan would replace the two middle schools with one, and three elementary schools with two.

“The first result is that we’ve proposed a consolidation from 10 schools to eight schools, which of course will result in operational savings, both in maintaining two fewer schools and the staffing,” Graner said.

He estimated a reduction of two principals, two assistant principals, four secretaries, six custodians and potential savings in areas like art when schools are combined.

There could also be economies of scale in the teaching staff, although he said it is too early to predict exact numbers. Groton had the equivalent of 526 full-time teachers in 2005, and this year has about 458.

Groton takes part in a number of regional programs with other districts, mainly associated with special education, he said. Groton is also part of a collaborative to buy fuel oil and electricity, Graner said.

But he added, “I think Connecticut has a history of sort of local control of education that I think people value a great deal.”

The district is feeling the pressures of school choice and competition for students. Groton has 406 children who attend magnet schools elsewhere, and is looking at ways to offer magnet school programs within the town to attract parents back. Next year, Groton plans to turn Northeast Academy into a performing arts magnet program for students within the district.

Enrollment at Northeast fell by about 20 students during the last two years, and since the school offers a performing arts program, it saw opportunity, Principal Paul Esposito said. Starting next year, Northeast Academy would accept eight to 10 magnet students in kindergarten and in first grade from elsewhere in Groton. In subsequent years, the school would add another eight to 10 kindergarten magnet students, until a solid percentage are from outside the immediate neighborhood.

“Families definitely believe in choice, they want choice and they have a choice now to go to private school or New London” for performing arts, Esposito said. “Our opportunity now will be to give them a choice to say right in Groton.”

d.straszheim@theday.com