A luxury condominium tower on Seaport Boulevard will break ground this spring after environmental advocates agreed to drop a lawsuit challenging the project, in exchange for $13.1 million in funding for a waterfront park, a public dock, and children’s programming.

The Conservation Law Foundation hailed the deal with developer Jon Cronin as a win in its push to make the waterfront more accessible. It was the result of months of behind-the-scenes negotiating while the two sides faced off in court.

The group had sued over a zoning plan for the 22-story building, saying it would wall off a key stretch of Boston Harbor. CLF agreed to drop the suit in exchange for a boat dock, the parks money, $5.4 million for programs that bring city youth to the waterfront, and clearer rules governing a 16-foot-wide HarborWalk that Cronin plans for the site.

“We think it’s a great victory for public access and for the quality of the Boston waterfront,” CLF president Bradley Campbell said. “It demonstrates that public access and waterfront development can go hand in hand.”

Cronin, a longtime South Boston restaurateur, has spent more than two years working to win approvals for the $260 million project, which would put a tower designed by architect Howard Elkus on the site now occupied by Cronin’s Whiskey Priest and Atlantic Beer Garden bars. In a statement, Cronin said he was glad the project — which is also being used to help finance low-income senior housing in South Boston and the new Martin’s Park along Fort Point Channel — is finally moving forward.

“It will be a fantastic addition to the neighborhood, with unprecedented community benefits,” he said.

The 150 Seaport building is one of several high-end condo projects along the city’s booming Seaport waterfront. But it emerged as a flashpoint in the broader debate over development and access to Boston Harbor after CLF stepped in as a fierce critic and sued to block it.

In settlement talks that took place on over several months, CLF had pushed for more money, arguing — in documents the group recently supplied to the Globe — that Cronin should pay as much as $40 million toward a waterfront park, to make up for zoning changes the project is receiving from the city. The developer pushed back, and eventually the sides agreed to $13.1 million, to be paid out over 35 years.
It’s not yet clear where that money will go. The funds will be controlled by the city, which increasingly uses private development to finance park expansion. The Trustees of Reservations is scouting sites and raising money for a new waterfront park in the Seaport, potentially along Fort Point Channel or on an unused drydock near Blue Hills Bank Pavilion. That’s one possibility, Campbell said. Another potential site is a submerged pier alongside the Blue Hills Bank Pavilion, known as Wharf 8 and Pier 7, which has long been slated for redevelopment.

“Our preference would be the Pier 7/Wharf 8 project, but that’s a decision that has to happen with the city,” Campbell said. “It’ll depend largely on the mayor’s priorities.”

A spokeswoman for the Boston Planning & Development Agency said BPDA officials hadn’t yet seen the settlement agreement but were “pleased the 150 Seaport Blvd. project is moving forward.”