LYNN — Mayor Jared Nicholson unveiled a massive $450 million development plan for the South Harbor site on Tuesday. The plan calls for constructing an 850-unit apartment complex with a first-floor retail space.

The project traces its origins back four years when former Mayor Tom McGee and Economic Development & Industrial Corporation of Lynn (EDIC/Lynn) Director James Cowdell met with developer Samuels & Associates to create a plan for the property, which serves as a gateway to the city. When Nicholson became mayor, the process expanded to include city department heads and councilors, including Ward 6 Councilor Fred Hogan and City Council President Jay Walsh.

10% of the 850 units will be set aside as affordable housing for those earning no more than 60% of the area median income. The city’s area median income from 2017 to 2021 was $63,922, according to census data. In addition to the housing, the new development will feature approximately 26,000 square feet of retail and restaurant use, an 8-acre public waterfront park, and shoreline restoration. The total area for the development will be 1.1 million square feet, Nicholson’s office said in a statement.

“This is exactly the kind of win from multiple perspectives that we’ve been working towards in development,” Nicholson said in the statement. “The vacant South Harbor site has been a barrier to accessing the waterfront for decades. The city has long recognized that this location could represent a transformative opportunity to create new housing and job(s), improved access to the waterfront and public open space, and additional benefits.”

Nicholson said the city has a partner in Samuels that shares its vision and master plan for the site and is willing to collaborate with officials to achieve both parties’ goals. While the plan went before the council on Tuesday, it is not expected to be voted on until later this month.

The proposal has already received site-plan approval from the city and was developed with the city’s comprehensive plan, housing production plan, and waterfront master plan in mind. Each of those plans was developed after a lengthy public process, and Nicholson said the new proposal truly represents the culmination of those efforts.

Cowdell described the project as the biggest in the city and one of the largest mixed-use projects in the pipeline outside of Boston. The statement said the project is expected to net $120 million in tax revenue throughout a 30-year period.

The city is proposing to give Samuels a 20-year tax increment financing agreement, which is essentially a subsidy for the redevelopment of the site, which has been vacant for four decades.

Cowdell said that in the past, proposals for the site were brought before the city but never moved forward.

Nicholson estimated construction would take place over a decade across three phases. The project is expected to generate hundreds of construction and retail jobs. Local hiring goals will be implemented, with the aim that 30% of the hours worked be performed by Lynn residents and at least 15% of the construction cost be paid by subcontractors that employ apprentices.

The proposal is tied into a broader effort by Nicholson’s administration to revitalize the city’s waterfront, including the revival of the MBTA ferry this summer and the extension of Blossom Street.

“In the past, Lynn essentially turned its back on the water, (and) put uses there that were not consistent with a community’s placement on the Atlantic Ocean,” Nicholson said in an interview. “We also don’t want to build a waterfront that turns its back on Lynn.”