Local environmental groups are preparing to protest a planned development that they say would destroy a silver maple forest that straddles the line between Belmont and Cambridge.
The protest, which is scheduled for Saturday, is the latest in a long series of attempts to challenge or prevent the proposed affordable housing development, which would be located on private property in the middle of the state-owned 120-acre Alewife Brook Reservation.
The conflict over the Belmont Uplands property has stretched on for the past 15 years, but after dealing with a series of legal challenges and appeals from state and local agencies, developer O’Neill Properties of Pennsylvania would be cleared to begin construction if it secures a building permit from Belmont.
The developer has already obtained all the necessary permits from the state and from Cambridge, and has submitted about 95 percent of the documents needed to secure a Belmont building permit, according to Glenn Clancy, the town’s director of community development.
Local environmental groups, including the Friends of Alewife Reservation, Green Cambridge, the Sierra Club, and the Belmont Citizen Forum, are organizing Saturday’s demonstration, set to begin at 10 a.m. with a rally near the MBTA’s Alewife Station in Cambridge, followed by a parade to the forest.
Environmental activists oppose the project for several reasons. They say destroying the forest would exacerbate climate change and flooding issues in the Mystic River watershed by removing land that acts as a natural sponge. They also say destroying the forest would squander an opportunity to preserve a natural area in a densely populated region that is home to 21 species of mammals.
“It’s the last of the large Boston-area urban wilds,” said Ellen Mass, president of the Friends of Alewife Reservation, whose group runs cleanups and educational walks in the forest. She added: “If those trees are cut down, Cambridge’s largest wetlands will be impacted.”
The project’s opponents are also planning to attend the Belmont Board of Selectmen’s meeting on July 7 to ask that the town delay issuing a permit until Cambridge completes its climate vulnerability assessment, expected to be later this year.
O’Neill Properties is applying for a 298-unit complex under the state’s Chapter 40B affordable-housing regulations. The law allows a developer to bypass local zoning laws in exchange for designating a certain percentage of a project’s units for income-eligible households, if less than 10 percent of the host community’s housing stock meets the state’s criteria for affordable housing. Belmont falls short of the threshold that would exempt it from Chapter 40B, according to Clancy.
He said the developer originally applied for a building permit for the project in September 2010, but since then the state changed its building code, so the company has been working to ensure that its plans comply with the new code.
O’Neill Properties did not return requests for comment.
Officials in surrounding communities say they regularly hear from residents who oppose the development. Jennifer Letourneau, Cambridge’s conservation director, said she often fields calls from people who are upset about the proposal.
“Residents of Cambridge, as well as abutting towns, just feel as though there is a missed opportunity to have space that does not have buildings on it,” said Letourneau. “They want to talk about it. They want to know why. They want to know how this is legal, how they’ve met the development threshold.”
The proposal passed the state Department of Environmental Protection’s scrutiny in 2010, when the agency decided that the developer had taken the proper steps to mitigate damage to the surrounding wetlands and protect nearby Belmont neighborhoods from flooding.
Belmont Town Administrator David Kale said that local officials have not taken a stance on the project, and that the developers have cleared a series of town requirements in order to move forward with the project. Kale also said it remains to be seen how the development would affect Belmont.
“I think that clearly, like with other projects that have happened, there may be an impact on the school-aged population, but we won’t know the exact number until the project’s completed,” Kale said.
Three acres of the parcel are in Cambridge, and Letourneau said that, in 2008, the city’s Conservation Commission granted the developers a permit to build a vegetated water-quality detention basin on the property. She said the Cambridge portion is protected from further development by a conservation restriction.
Several years ago, officials and activists discussed a potential plan for the surrounding communities to purchase the property, which was assessed at $13 million, but that never came to fruition.
“There’s been lots of conversation with people wishing they could’’ raise the money, said state Senator William Brownsberger, “but that hasn’t come together throughout the years.” The Democrat from Belmont said he opposes developing the land, and would like to have the silver maple forest become part of the Alewife Reservation.
“It could make for a very great wilderness area, a park for people to come to from Arlington, Belmont, and Cambridge,” Brownsberger said.
Emily Cataneo can be reached at email@example.com.