Students return to class after recess to portables built on the campus of Rachel Carson Elementary School in Gaithersburg. (Marvin Joseph/The Washington Post)

At Woodlin Elementary in Silver Spring enrollment is up, but expansion is still an idea in waiting. The result is a colony of portable classroom trailers clustered behind the school, an outpost of learning where 150 students in second and fifth grades spend much of their days.

The setup, which has frustrated parents, is a stubborn reality in fast-growing Montgomery County. Enrollment has surged by 16,000 students in seven years in Maryland’s largest school system, but classroom construction has not kept pace.

With more than 9,000 students in portable classrooms countywide, some parents have become increasingly vocal in pushing for new construction and urging more immediate improvements. They worry about recess areas, security controls and children walking outside to reach bathrooms in the main building.

“We feel the portables are treated as temporary solutions, but they are not really temporary anymore at the elementary school level,” said Laura Stewart, PTA president at Woodlin, where 25 percent of the student body is housed in classroom trailers.

Looking toward the legislative session that starts in January, county and school leaders have pledged to work with Montgomery’s state delegation to press for increased school-construction funding to meet Montgomery’s growing need for classroom space.

But the efforts come at a time of economic uncertainty, with recent projections of major revenue shortfalls in Maryland.

“The need is definitely there,” said school board President Patricia O’Neill (Bethesda-Chevy Chase). What’s less sure, she said, is funding. “Unfortunately, schools compete with roads and libraries and all of the challenges that every community has.”

Montgomery’s school board recently requested $223.3 million in additional funds for the district’s six-year capital budget, much of which would move up the timelines on 36 delayed construction projects.

With rising enrollment, portables used to relieve crowding in the county have ticked up to 404, increasing from 382 last year. Ninety percent are at elementary schools, and more than 40 Montgomery public schools have five or more.

Parents at Woodlin launched a petition this fall, calling on school officials to take action to address crowding. So did parents at Rachel Carson, in the Kentlands area of Gaithersburg, the county’s largest elementary school.

Many parents at Carson and Woodlin praise educators at their schools but say they are frustrated by the over-enrollment.

With 1,025 students, Carson is 358 over its capacity of 667, according to district figures. It has 10 portables used as classrooms. Woodlin is smaller but is 164 students over its capacity of 462. It has nine portables.

Students return to class after recess to portables built on the campus of Rachel Carson Elementary School in Gaithersburg. (Marvin Joseph/The Washington Post)

“It’s just not built for that many kids,” said Andrew Ross, a Carson parent who cited an array of concerns, including insufficient recess space, long lines for lunch, availability of restrooms and a need for security cameras near portables.

Carson parents have started a Facebook page to address the challenges.

Carson Principal Larry Chep says the school has managed well with its large enrollment, and he noted that Carson is a Blue Ribbon school. Chep says that his school, like others, puts procedures in place that “ensure kids are safe.”

District officials point out that portables have been around for decades and are widely used in other school systems. While not ideal, portables don’t last forever and are the best way to manage enrollment spikes, said Bruce Crispell, director of long-range planning for Montgomery schools.

Even when schools are over capacity, individual class sizes are not larger than at other schools, he said.

Construction projects are not underway to address crowding at Carson or Woodlin.

Woodlin is part of a capacity study of down-county elementary schools that is slated to start soon. Carson’s site is limited, so the school system plans to look into projects at three adjacent schools. In the fall, the superintendent might recommend such projects or suggest a new elementary school in the area, officials said.

At Woodlin, the issue of crowding heated up this fall after two more portables arrived for the school year, and the units were reconfigured in a way that swallowed up a large chunk of a grassy field used by children to play soccer. Parents were already dismayed that the school was not scheduled for a classroom addition.

“We have very little green space for the kids to play at this point,” said Karen Miller, PTA vice president.

Miller and others argue that, as portables reach a critical mass at schools, more planning should be done to address how such facilities affect student needs.

Parents say the lack of restrooms, for example, forces students to go outdoors to get to the main building, raising concerns about inclement weather and security. Some want security cameras installed.

Some suggest more windows in portables or more staff.

“Portables are a way of life, so they need to have some kind of a plan to make sure these issues are addressed, especially safety,” said Woodlin parent Melissa Polito.

District officials say each school makes portables a part of its security protocols and training. The district’s security division is meeting with Woodlin’s principal and PTA leaders after winter break, said Dana Tofig, spokesman for Montgomery schools.

Tofig said the district seeks to respond to parent concerns and is starting work on a canopy over the walkway from the portables to the school building at Woodlin, as it has done elsewhere.

“We’re always working with schools and school communities to make the portables as much a part of the school building as we can, within the means that we have,” he said.

At Woodlin, as parents have voiced concerns, they also have tried to make the best of it. This school year, the PTA organized a Pretty Up the Portables effort.

Kristi Delovitch, mother of two, led it. She said she is concerned about portables and would prefer her child be assigned inside the school. But the day after Thanksgiving, Delovitch and her family adorned the portables with glittery ribbons and silver and gold foil stars, hoping to strike a winter wonderland theme.

Woodlin’s teachers added their own decorative touches, too.

“My point of view is: This is a reality, this is where we are right now, and I want to do my part to make sure the kids in the portables are getting that great warmth that kids inside the school are getting,” Delovitch said.