After 15 months of work and $16 million in funding, three prime sections of the battered turf on the Mall have been restored to the exquisite green of a major league outfield.

The area, roughly between Third and Seventh streets NW just west of the Capitol, still is fenced off while workers put on the finishing touches.

But in 10 days, just as the fences come down, an army of an estimated half-million citizens is expected to descend on the Mall to celebrate President Obama’s second inauguration, on Jan. 21.

But fear not for the new grass — at least most of it.

Officials plan to put down several acres of a special plastic flooring to “protect the . . . grass from being trampled into oblivion,” said Alice McLarty, landscape architect for the National Mall and Memorial Parks.

See how the National Mall appeared during Obama’s first inauguration compared to late 2012.

“After the last inauguration, we didn’t have much grass left,” she said.

But because of a bureaucratic mix-up, only part of the new turf will be protected.

For the inauguration, the section of the Mall with new turf has been placed under the control of two different committees — a presidential committee and a congressional committee.

The National Park Service said the presidential committee plans to pay for the turf protection in its sector, which runs from Fourth Street to Seventh Street NW.

But the congressional committee says it can’t pay for its portion, the area from Third Street to Fourth Street. It was told about the turf protection too late and has no money budgeted for it.

“Given the time and budget constraints, we simply can’t accommodate this request, which came to us very late in the planning process,” said Matt House, spokesman for the Joint Congressional Committee on Inaugural Ceremonies.

Asked about the fate of the unprotected portion of the turf, McLarty said: “I don’t have a crystal ball.”

The flooring that will be installed is called Terraplas, according to the Trust for the National Mall. It lets in light and water and won’t harm the turf. It can be removed afterward. And all will be well as long as it’s not down for too long.

The grass on the Mall has been an eyesore for years, and a painful issue among advocates for the National Park Service’s elegant landscape between the Capitol and the Lincoln Memorial.

Indeed, much of the grass on the rest of Mall still looks rugged. And there is concern for the hard-won new turf and its support systems.

“We’re worked up about it, too,” said Caroline Cunningham, president of the Trust, the Mall’s official nonprofit, fundraising partner. “But not in a bad way.”

The new turf was designed with heavy use in mind, she said.

“The Park Service always knew that it was going to be a heavy-trafficked area.”

Cunningham said officials expect damage, not just from the inauguration but from other gatherings. They are working with a seed company to produce new grass identical to the restored grass to replace any that is destroyed.

“We spent a lot of money to make this space look the way it looks,” said John E. “Chip” Akridge, founder and chairman of the trust. “And we want to maintain it that way. . . . I think we’ve got most everybody [headed] in that direction. . . . It doesn’t make a lot of sense to be penny-wise and pound-foolish.”

“Look, this is the presidential inauguration,” he said. “It’s extremely important that we make these operational rules stick . . . because if it’s good enough for the president, it’s good enough for everybody else.”

Robert Vogel, superintendent of the National Mall and Memorial Parks, said, “This is really our first test, the first large event since we put the turf down.

“The National Mall . . . is a nationally significant landscape,” he said. “And, as such, we shouldn’t abuse it. But we certainly can use it. It will always be America’s front yard.”

“Sometimes in the past we allowed the turf to be destroyed and then went in and repaired it,” he said. “The goal is to say, ‘Well, it’s not okay to destroy it in the first place.’ ”

The restored area of the Mall includes the three central panels of grass between Third and Seventh streets. In September 2011, the park service began digging up the panels, installing a new irrigation and drainage system, and putting the sod atop special new soil.

The sod was installed in huge 60-foot-long rolls last summer.

The congressional inaugural committee said it was not notified of the extra spending request until December, and its budget had long been set at $1.23 million.

The protective flooring in its sector was expected to cost at least $115,000, the committee said. The cost to protect the presidential sector was about $800,000, it said.

In addition to the turf restoration, a granite border panel has been installed around the panels to help with drainage and decoration. Two giant cisterns have been buried to catch and reuse runoff, and a turf manager has been hired to oversee things.

Restoration of the rest of the central Mall is planned for later, as far west as the grounds of the Washington Monument.

The challenge has always been to free the Mall for maximum public use yet preserve its beauty.

“We don’t gate it off,” McLarty, the landscape architect, said. “We don’t lock it up at night. It’s not like a private garden. . . . We have many, many events down there. Cumulatively, they have a tremendous deleterious effect on the lawn.”

But for now, said Vogel, the park superintendent, “ it looks fantastic.”