How is Oak Harbor going to keep up with the expected expansion at Naval Air Station Whidbey Island? Schools and housing will be two obvious areas of impact.

Using 2016 as a baseline, the number of personnel associated with NAS Whidbey Island is projected to increase by 1,320 people, or 7 percent, to 19,560, by 2018 and by 3,740 people, or 20 percent, to 21,980, by 2019.

Those numbers include Navy personnel, their families, civilian contractors and government employees.

At some point, the number will drop slightly because a military reconnaissance group will be broken up, but it’s not clear when that will occur, said Navy spokesperson Mike Welding.

DESPITE THE projected personnel increases, the Navy has no plans to build additional housing, Welding said. The Navy currently billets people in 1,493 houses or townhouses on government property — though not on the base itself — and in 1,137 rooms in on-base barracks.

A 2013 study of all housing available within a 100-mile radius of the base showed a surplus through 2020, he said.

The base is considering requesting a new study but has not yet taken any steps toward doing so, Welding said.

Signs of a housing shortage are already evident, however. Though home prices are currently high and interest rates near historic lows, the supply of Oak Harbor houses for sale is “one of the lowest I’ve seen in a long time,” said Erik Mann, a Realtor with Windermere Real Estate in Oak Harbor. So when the base expands, “I’m not sure where all the sailors will end up housed.”

“I’m at a loss as to where everyone is going to go,” Mann said.

AMONG OAK Harbor’s top five property managers, “we have 19 rental houses or apartments among us — we’d expect to have about 100,” said Jason McFadyen, the managing broker for Windermere Property Management.

“I normally have 20 to 30 rentals available, not three,” McFadyen said. “It’s really a very acute shortage. I don’t know what can be done. There are only so many places to live.”

Because rentals are scarce, rents are rising, he said.

Some signs of expansion are showing in Oak Harbor. The city in early February approved construction of 62 homes on 10 acres off Swantown Road near the Whidbey Island Golf Course, said Barbara Spohn, the city’s director of economic development.

A 26-unit apartment building on Barrington Drive is in the pre-application phase. And construction firm Landed Gentry is building several single-family homes on Fairway Point Drive.

But Windermere’s McFadyen said he isn’t optimistic that demand can be met. “I’d love to say building will be the answer, but that would take a long time and barely touch what we need.”

USUALLY, OAK Harbor’s Tara Property Rentals has 10-15 properties, out of its inventory of 300, available to rent at any one time, said Brittany Azevedo, the firm’s receptionist.

Right now, she said, “we have nothing. As soon as I put something up, it’s gone.”

She attributes to shortage to “a huge increase in Navy personnel,” adding, “there’s nothing we can do to accommodate the coming expansion.”

The shortage of rental housing may even be spreading southward down the island. The rental market in Freeland and points south is “very tight,” said Ben Robinett, a Realtor with Windermere Property Rentals in Freeland.

Robinett said he only has a few naval renters, but has been getting some phone calls from Navy personnel inquiring about rentals.

“I think with the expansion, it’s only going to get harder to find available rentals,” he said.

FOREST CITY Enterprises Inc., of Cleveland, in November agreed to sell its entire military-housing portfolio of approximately 15,000 homes to privately held Hunt Companies Inc., of El Paso, Texas.

The sale still hadn’t closed as of early February.

Forest City owns and manages 1,499 houses serving NAS Whidbey, said base spokesman Tony Popp.

“That purchase is the extent of our interest in Oak Harbor or really of any of the markets we’re invested in,” said Brenda Christman, a Hunt Co. spokesperson.

THE OAK Harbor Public School system is already preparing to accommodate the boom in Navy-family students.

In fall 2015, the school system had 188 additional Navy-family students in grades K-12 than the year before, according to data it provided. It anticipates up to 700 more Navy-family students by the fall of 2020 because of the base’s expansion. A full 92 percent of Navy-family students attend school in Oak Harbor.

Oak Harbor schools have 2,793 Navy-family students in the 2015-16 school year. As of early February, that number was projected to grow to 2,884 in 2016-17, 3,195 in 2017-18, 3,448 in 2018-19, and 3,530 in the following two school years.

Civilian student growth, which consistently exceeded Navy-family student growth until the fall of 2015, will increase by at least 50 students per year.

But Navy-family growth will far exceed civilian growth.

TO ACCOMMODATE all of that growth, the school system plans to add at least 10 portable classrooms by fall 2016 for the 2016-17 school year. Over the following two to four years, it plans to expand by either adding space through modular or conventional construction, using more portables or some combination of those.

In six years, it might build a new elementary school.

Funding for those plans could come from a variety of sources, possibly including the Department of Defense and the Navy, the school system said. In an October 2015 letter to the U.S. Department of Education seeking Impact Aid funding, Washington state’s two U.S. senators and U.S. Rep. Rick Larsen wrote that Oak Harbor’s school system faces “severe fiscal difficulties.”

They said “a surging volume of children from military families” is among the budgetary pressures it faces.

By the numbers

Estimated maximum NAS Whidbey Island personnel (including dependents):

2016*: 15,840 military + 2,400

civilian =  18,240

2018: 17,160 military + 2,400

civilian =  19,560

2019: 19,580 military + 2,400

civilian =  21,980

*Actual

Source: NAS Whidbey Island