Then and Now: Paulina Lake Dam Removal

More than a century after the Paulina Lake Dam first altered the Paulins Kill River, the site now tells a very different story. A recent return visit confirms what restoration practitioners know well: when barriers are removed, rivers heal. Today, the Paulins Kill flows freely through the former Paulina Lake Dam site, reconnecting habitats that had been fragmented for generations.

The Paulina Lake Dam stood for nearly 130 years in Blairstown Township, Warren County, NJ. Constructed in the late 1800s to generate hydropower, it had long outlived its original purpose. Like many aging dams across the country, it remained in place despite no longer serving a critical function, while continuing to disrupt river processes and pose growing safety risks.

As reported in CentralJersey.com’s recent feature “The fall of dams and rise of rivers,” the majority of New Jersey’s approximately 1,700 regulated dams were built in the 19th and early 20th centuries to power mills that no longer exist. Fewer than a dozen still serve an essential purpose today. Many persist due to nostalgia, misunderstanding, or uncertainty around removal—despite blocking fish passage, trapping sediment, warming water temperatures, exacerbating flooding, and increasing the risk of failure.

The removal of Paulina Lake Dam was led by The Nature Conservancy (TNC) in partnership with Blairstown Township, New Jersey Department of Environmental Protection, U.S. Fish and Wildlife Service, Riverlogic–Renova Joint Venture, and Princeton Hydro. The Office of Natural Resources Revenue awarded a grant to TNC to fund a substantial portion of the removal through the Paulins Kill and Pequest Watershed Natural Resource Restoration Grant Program.

The project advanced through carefully sequenced phases, beginning with controlled notching in late 2023, followed by full demolition and sediment management in 2024, and transitioning into final adaptive management and habitat enhancement in 2025.

What the River is Showing Us Now

The ecological response has been swift and visible.

With the dam removed, more than 7.6 miles of mainstem and tributary habitat have been reconnected at the Paulina Lake site alone. The removal of the Paulina Lake Dam represents one important element of a longer-term, watershed-scale restoration initiative launched in 2013 to restore connectivity and ecological function along the Paulins Kill River. As the downstream most dam on the river, its removal builds upon earlier restoration milestones achieved through the removal of four dams: the Columbia Lake Main and Remnant Dams in 2019, the County Line Dam in 2021, and now the Paulina Lake Dam, progressively reconnecting approximately 45 miles of mainstem and tributary habitat.

Since 2016, The Nature Conservancy has also implemented a 10-year Measures and Monitoring Program to track ecological response and conservation outcomes, providing clear evidence that coordinated, science-based restoration can support a healthier, more resilient river system.

The river channel is actively stabilizing, riffle and run sequences are re-forming, and previously inundated areas are beginning to revegetate. Cooler water temperatures and the restoration of sediment transport processes are enabling the Paulins Kill to function more consistently with a cold, free‑flowing, coarse‑substrate stream system.

This series of aerial drone photos was captured during a site visit in November 2025:

This recovery is already benefiting aquatic life. As Beth Styler Barry, Director of Freshwater Programs for The Nature Conservancy in New Jersey, noted in the CentralJersey.com article, “We’re already seeing American shad above the dams that were removed. We’re seeing sea lamprey and American eel. It used to be that only the biggest eels could make it upstream. Now we’re seeing all age classes.”

By reconnecting upstream and downstream populations that had been isolated for generations, the project has also restored connectivity for rare freshwater mussels, including the endangered dwarf wedgemussel (Alasmidonta heterodon) and triangle floater (Alasmidonta undulata).

“All of the organisms in a river like the Paulins Kill evolved to live in a cool, flowing, rocky-bottom stream,” Styler Barry told CentralJersey.com. “When you restore flow, the river begins to heal itself.”

Watch the Project from Start to Finish

A newly released project video captures this transformation in a way that still images and written updates cannot.

Drawing on aerial footage collected by The Nature Conservancy’s Volunteer Drone Team prior to demolition and by Princeton Hydro throughout and after construction, the video documents the full arc of the Paulina Lake Dam removal from initial notching through full demolition and into the restored conditions visible today. The footage provides a comprehensive look at dam removal in practice, illustrating how careful sequencing, sediment management, and adaptive design allow rivers to recover rapidly once barriers are removed.

Click below to watch the full project video and see the transformation unfold:

Beyond ecological gains, the removal of Paulina Lake Dam has significantly improved public safety and community resilience. In CentralJersey.com, Geoffrey M. Goll, PE, President of Princeton Hydro, emphasized the long-term risks associated with aging dams. “If you don’t take care of them, they’ll come out on their own—and that’s a much bigger problem. Once dams are properly removed, people start to see the value of a free-flowing river.”

Many dams were never designed to withstand today’s hydrologic conditions. With climate change driving more frequent and intense rainfall events, proactive removal reduces flood risk, eliminates inspection and maintenance liabilities, and allows rivers to function as more resilient, self-sustaining systems. At the Paulina Lake site, removal has also improved recreational access and restored a more natural landscape for the community.

Looking Ahead

While the Paulins Kill now flows freely through the former Paulina Lake Dam site, final project phases focus on adaptive management, targeted bank stabilization, habitat feature enhancement, and native tree planting to support long term ecological resilience. As the river continues to adjust and evolve, the Paulina Lake Dam site stands as a clear example of what is possible when outdated infrastructure is thoughtfully removed and natural systems are given the opportunity to recover.

To learn more about TNC’s work to restore the Paulins Kill River, click here. To learn more about Princeton Hydro’s work to remove dams and restore rivers throughout the Northeast, click here.

• Dam and Barrier
• Engineering
• Natural Resource Management
• Resiliency
• Stream Restoration