The city is closing Thomas Square to the public for about six months for what’s being described as “a maintenance project” beginning the week after Christmas, Mayor Kirk Caldwell’s administration said Friday.

Preparation work is slated to begin Monday, and the 6.5-acre park will close incrementally starting with the quadrant at South Beretania and Victoria streets, city officials said.

The $1.18 million project will include removal of mock orange hedge, grading, a new irrigation system, pruning of several large Indian banyans, removal of sick or unhealthy trees, and replacement of existing Bermuda grass with El Toro Zoysia grass across the entire lawn.

Area residents, City Council members and community activists have been raising objections to long-term plans for the park. They are worried that the historic parcel will be transformed into a cash-making venture under the administration’s plan. The strongest objections have been to the proposed transfer of Thomas Square’s oversight to the Department of Enterprise Services from the Department of Parks and Recreation, and plans for a 468-square-foot concession building.

In the spring the Council knifed out $1.95 million designated for the long-term project, which also includes a flagpole, a statue, a rock wall with the state motto and other features aimed at commemorating La Ho‘iho Ea, the 1843 restoration of the Hawaiian kingdom after a five-month takeover by a rogue British naval officer. A stage for performances is also proposed.

Robert Kroning, the city’s director of design and construction, and Chris Dacus, an executive assistant for historic parks and projects, insist the current project is not part of that long-term master plan.

None of the permitted organized activities that the park is known for — including pet shows, arts festivals and other cultural events — can take place during the closure.

Construction barriers that will surround the exterior of the park will start being installed Monday. The restroom station along Victoria Street will not be open during the full closure.

The sidewalks along all four sides will remain open throughout the project.

Kroning said the intent is to transfer Thomas Square to Enterprise Services when the short-term work is done. “I know the desire is for that to happen when the project is complete,” he said.

City officials said the long-term project is now being studied under an environmental assessment. The goal is to finish that work by July 31, 2018, the 175th anniversary of Restoration Day.

Thomas Square played a significant role in the restoration, and the park has been the site of an annual commemoration each July 31 since 1985.

Councilwoman Ann Kobayashi, chairwoman of the Budget Committee and the Council member who represents the district where the park sits, said she’s OK with the short-term project but has strong reservations about the long-term one.

“As long as money is being used to maintain it … that’s fine,” she said.

But she said she’s troubled that many area residents and other park users complained they had not been consulted about the long-term plans. “People want it to remain a park; they don’t want it commercialized.”

Kobayashi said if making money is not the goal, she sees no need for the park to be transferred to Enterprise Services, which now oversees city golf courses, Blaisdell Center and Waikiki Shell.

Dacus said the transfer will allow more staff, particularly those who already take care of the Blaisdell complex, as well as other resources to be used for the park. Now, he said, Thomas Square is the responsibility of a two-person Parks and Recreation crew that is also responsible for a host of other parks.

The city held 23 gatherings with interested parties before May and has held another nine, including three widely publicized meetings, since then, Dacus said.

The concession stand will be 468 square feet, smaller than the restroom facility, he said. Its major intent is not to make money, but provide a useful service for parkgoers, he said.

Henry Curtis, executive director of watchdog group Life of the Land, is suspicious of the administration’s plans and thinks the city may be violating the terms of a state executive order that gives the city control of the park under a specific set of rules.

Curtis recently sent a letter asking the Board of Land and Natural Resources to neither amend nor give the city a new executive order allowing for the transfer to Enterprise Services. The letter, dated Nov. 29, is also signed by other organizations and individuals who object to the long-term changes.

The city has promised to maintain the site as a park through a series of agreements, Curtis said. “The city now wants to radically change how the people use Thomas Square,” he said.

The city needs to do a completely new environmental assessment because the public draft does not state specifically whether the city intends to keep the promises it made as spelled out in the most recent order, Curtis said.