The City of Boston, Baker administration officials, and key Beacon Hill lawmakers have reached a tentative agreement on a deal that would smooth the way for a massive skyscraper to rise over Winthrop Square and could help finance the Rose Fitzgerald Kennedy Greenway over the next decade.
State Representative Aaron Michlewitz Monday filed a bill that would change laws governing shadows cast on Boston Common and the Public Garden, key to plans for a 775-foot tower that developer Millennium Partners wants to build on the site of a shuttered city parking garage on Devonshire Street.
As part of closed-door negotiations around the legislation, Michlewitz, Mayor Martin J. Walsh of Boston, state officials, and the nonprofit that runs the 17-acre Greenway are finalizing a deal that could generate $2 million to $3 million a year in funds from the city, state, and neighboring property owners.
While parks advocates and Millennium Partners are still negotiating more protections for Boston Common and the Public Garden, city and state officials said they hoped the Greenway deal would allow the Winthrop Square project to move forward, while also creating a reliable stream of cash for the Greenway.
“This is a huge win for my constituents,” said Michlewitz, who represents much of downtown Boston and whose support was considered key to passing a new shadow law. “The Greenway is something that’s used by everyone in the City of Boston and the Commonwealth. For us to get something to help it long term is a huge victory for all of us.”
The state owns the land that the Greenway is on and currently gives the Greenway Conservancy $2 million a year, about 40 percent of its budget, to run and maintain the park. But the agreement expires June 30 and the state, which has contributed more than $15 million since 2009, has long warned it no longer wants to commit that kind of money.
Under the agreement — which still needs approval from several oversight boards and hinges on changes to the shadow laws — Boston would set aside $5 million of the $153 million Millennium is paying to buy the Winthrop Square site to create a trust fund for maintenance of the Greenway. Officials expect interest from that fund will generate about $250,000 annually for the park, which draws throngs of people to the heart of the city in the summer.
Meanwhile, the Greenway Conservancy is talking with the owners of buildings along the park — many of whom have seen their property values rise since it opened — about creating a special taxing district to kick in private money for park upkeep, although details of that arrangement are still in flux.
The city has long been reluctant to pay for the Greenway because it is on state-owned land over the Thomas P. O’Neill Jr. Tunnel created by the Big Dig. But Walsh said Monday he believes the new arrangement will be good for Boston residents.
“The entire city benefits from it,” he said. “The last thing I want to see in the middle of Boston is a park that is being underfunded, that falls into disrepair and hurts our city.”
The tentative agreement is the latest example of the Walsh administration using funds from Winthrop Square to win support for the project, which would create one of Boston’s tallest buildings but has also stirred controversy for the new shadows it would cast on two historic parks.
The mayor already has earmarked $102 million from the expected Winthrop sale proceeds to pay for improvements to Boston Common and Franklin Park and to renovate public housing in East Boston and South Boston. Those plans were key to the tower project winning support from the Boston City Council.
Adding Greenway funding to the mix helped win over Michlewitz, an influential lawmaker whose district includes Winthrop Square.
He had suggested the state could thwart the deal if the city didn’t help fund the Green- way.
A few other Boston lawmakers have expressed doubts about the wisdom of changing the 25-year-old shadow laws, and they could yet throw up roadblocks. But Michlewitz, state Senator Joseph A. Boncore, and Walsh — a former state legislator — all said they’re cautiously optimistic the proposed amendments will win approval on Beacon Hill and be signed into law by Governor Charlie Baker.
Some critics still have concerns about reworking the shadow laws, fearing it could set a precedent for more building projects that could cast shadows on the parks. But opposition has quieted since the council in April voted 10-3 to support the shadow laws change.
Friends of the Public Garden, a nonprofit that before the council vote led opposition to the project, continues to talk with city officials and Millennium Partners about a deal that could offer more protections and “a significant investment” for the Common and Garden, said executive director Liz Vizza.
That is a separate discussion from the emerging Greenway deal. A proposal for the Garden and the Common — which could involve long-term funding for the parks beyond the $28 million in Winthrop money that Walsh already earmarked for the Common — could be finalized over the coming months as the tower moves through permitting process with the Boston Planning & Development Agency.
Executives with the Greenway Conservancy said there are still details to be finalized as well, both with the state and to establish the taxing district, which would be similar to Downtown Crossing’s Downtown Business Improvement District.
The new entity would require a majority of property owners along the park to sign on and council approval.
“The pieces are coming together,” said Conservancy executive director Jesse Brackenbury. “It’s premature to say it’s done, but it’s getting close. We are excited about the prospects.”Tim Logan can be reached at email@example.com. Follow him on Twitter @bytimlogan. Joshua Miller can be reached at firstname.lastname@example.org. Follow him on Twitter @jm_bos.