A 150-year-old granite retaining wall at the historic Lead Mills Conservation Area partially collapsed into the Forest River, prompting Salem officials to hire an engineering firm to assess the damage and develop repair plans.
The wall failure occurred along Lafayette Street where the roadway crosses from Salem into Marblehead at the mouth of the Forest River. Salem City Engineer Deborah Duhamel confirmed the city has retained an engineering consultant to evaluate the collapsed section, recommend corrective measures and provide cost estimates for repairs. She did not have a timeline for completing the engineering assessment or beginning repairs.
Mark MacRae, a 50-year Marblehead resident and retired construction executive, first alerted the Marblehead Current to the recent collapse after photographing the site. MacRae, who worked for 45 years in building construction with expertise in deep foundations and earth retention systems, had been monitoring the wall’s deterioration for more than a year.
“It has been hanging out over the water for so long, and they never did anything about it,” MacRae said, describing how the wall’s face had been leaning noticeably over the water.
The collapsed granite blocks now rest underwater at high tide and are visible only during low tide, MacRae noted.
The Lead Mills site sits on land that was once a tidal flat, later filled and reinforced with granite seawalls to support 19th-century railroad infrastructure, according to MacRae. The Boston and Maine Railroad built the retaining walls to create elevated land for train tracks that crossed from Salem into Marblehead along what is now Lafayette Street.
“All of that is reclaimed land,” MacRae explained. “When the railroad came to Marblehead, they had to build the land up to support the tracks. They had to fill in the ocean, the tidal flats where the ocean would come in at high tide.”
The site later became home to the Forest River Lead Works, established in 1840 as one of the largest lead manufacturing facilities in the country. The industrial complex produced white lead for paint, bullets for the Civil War and other products until a fire destroyed the last buildings in 1968.
In 2012, Salem and Marblehead jointly purchased the 4.5-acre property using state grant funding and private donations, converting it into a conservation area for passive recreation. The site now features walking trails and connects to regional trail networks.
MacRae attributed the wall’s failure to hydrostatic pressure when rainwater saturates soil behind the granite blocks. Unlike modern retaining walls that incorporate drainage systems, the 19th-century structure lacked adequate infrastructure to manage water accumulation.
“The rain causes hydrostatic pressure on the back of the wall,” MacRae said. “Unless they have proper drainage to capture the rain and let the rain seep through the wall, the wall acts like the side of a swimming pool.”
He warned that other sections of the wall show similar signs of instability and require attention before additional collapses occur. MacRae compared the situation to recent seawall failures in neighboring Swampscott, where inadequate drainage contributed to wall collapses during heavy storms.
“They could have gone in with an excavator and excavated the soil behind the wall and relieved the pressure,” MacRae said. “They still can fix it upstream and downstream of that spot, because that spot fell, but the rest of it hasn’t fallen yet.”
The conservation area attracts visitors who use the path, a former railroad right-of-way that connected Salem and Marblehead trail systems. The site also serves as an important coastal habitat for migratory birds along the Atlantic Flyway.
MacRae emphasized the importance of addressing the entire wall system proactively rather than waiting for additional failures, noting his experience with similar infrastructure challenges in urban construction projects.
“It’ll never be cheaper to fix it than it is right now,” he said. “Once it falls into the water like it has now and even more so the more it goes unaddressed, it gets more and more expensive.”
