LYNN — Instead of a traditional seawall, a development team will build a concrete stabilization mat to prevent erosion by breaking up waves before they reach the planned apartment buildings at the former Beacon Chevrolet site.
Work is expected to be completed on the $1.4 million revetment this week, the first phase of the $90 million redevelopment of the site, dubbed North Harbor, into 332 market-rate apartments, according to Eric Loth, managing director of Minco Corporation, the North Andover-based development team.
The 48,000 square-foot revetment is also meant to support a publicly accessible harbor walk connection along the city’s coastline, which the development team plans to connect from the Lynn Heritage State Park to the Clocktower Business Center on the Lynnway.
The revetment consists of articulated concrete block mats, which was given the go-ahead following a lengthy process with the Massachusetts Department of Environmental Protection that involved getting the mats designed and permitted to put into the site, according to Loth.
The harbor walk and a linear park that ties into it will be toward the top of the mat, which consists of pieces of concrete tied together with steel cables that were placed on top of crushed stone. All of the voids in the revetment will be planted with grass, which provides more habitat for birds and wildlife, Loth said.
Loth said the idea came from noticing the integrity of the granite-faced block was failing at Lynn Heritage State Park, which is next door to the site.
“We didn’t want to do the same thing,” said Loth. “This dissipates the waves. The waves can go over it.”
The site is deep into the Lynn Harbor so the water is shallow, meaning there aren’t as many waves. Loth said if they were positioned in a place with heavier wave action directly facing the ocean, a different kind of seawall would have been needed.
“The site had a revetment at one point,” Loth said. “Some of it was stone. Most of it had fallen apart. (We) needed to do something to rearmor the site.
The revetment is being paid partially through a coastal infrastructure grant that was awarded to the city by the Seaport Economic Council. The construction is being conducted by Charter Engineering, the firm that was awarded the bid from the city.
Loth said a groundbreaking on the development is expected later this summer, which will transform the 14-acre site across from North Shore Community College on the Carroll Parkway. The site, which sat vacant into three decades, is expected to feature multiple residential buildings with Boston skyline and water views.
Everything about the development has been later than anticipated, Loth said. Construction has been delayed by two major factors, which has included navigating through Chapter 91 licensing, the commonwealth’s primary tool to protect and promote public use of its waterways, and completing a land swap involving a state easement.