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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.

[caption id="attachment_19094" align="aligncenter" width="800"] Paulina Lake Dam aerial view prior to removal. Photo by Jim Wright/TNC/LightHawk[/caption]  

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: [gallery link="none" size="medium" ids="19109,19110,19111"]

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: [embed]https://www.youtube.com/watch?v=T6dQRRU5DCE[/embed]

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. [post_title] => Then and Now: Paulina Lake Dam Removal [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => then-and-now-paulina-lake-dam-removal [to_ping] => [pinged] => [post_modified] => 2026-01-28 15:59:36 [post_modified_gmt] => 2026-01-28 15:59:36 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=19057 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => WP_Post Object ( [ID] => 15921 [post_author] => 1 [post_date] => 2024-11-11 15:54:21 [post_date_gmt] => 2024-11-11 15:54:21 [post_content] =>

For the first time in over 200 years, the lower Bushkill Creek is now free-flowing and fully reconnected with the Delaware River and, ultimately, the Atlantic Ocean. This tremendous achievement signals a turning point for the ecological health of the Bushkill Creek watershed, supporting the passage of migratory fish species, bolstering ecologically beneficial freshwater mussel populations, reconnecting river habitats that benefit fish and wildlife, and enhancing water quality across the Delaware River Basin, which provides drinking water to millions of people.

"This significant, yearslong restoration effort exemplifies the power of conservation partnerships to achieve profound ecological impact,” said Princeton Hydro President and Founding Principal Geoffrey M. Goll, PE “The restored Bushkill Creek is more than a reconnected waterway—it is a revitalized natural resource that enhances biodiversity, supports community recreation, and contributes to the local economy in sustainable ways.”


Restoring Bushkill Creek’s Natural Flow

Bushkill Creek begins at the foot of Blue Mountain in Bushkill Township, Pennsylvania, and flows for 22 miles through agricultural and suburban areas, including Easton. The limestone stream supports a thriving wild brown trout population and is designated as a “high-quality, cold-water fishery” cherished by anglers and the local community.

Since 2021, Wildlands Conservancy has led the charge to remove five aging dams along Bushkill Creek. While these structures once served industrial and community functions, they had become barriers to fish migration, disrupted the creek’s natural flow, and contributed to localized flooding and water quality issues. Now, with these obstacles cleared, Bushkill Creek flows freely from its headwaters to its confluence with the Delaware River.

The map below, created by the Wildlands Conservancy, shows the locations of four dam removals on Bushkill Creek:

Along the creek, the removal of Dam #2 signifies a momentous occasion in its restoration journey, representing the most recent advancement in dam removal efforts.

[embed]https://youtu.be/zqO-Pz58bI8?si=A5JVmIjnDKpyn4Hu[/embed]

The Power of Partnerships in Restoring Bushkill Creek

Led by the Wildlands Conservancy, the restoration of Bushkill Creek involved more than 20 stakeholders, including the Delaware River Basin Commission, Lafayette College, Pennsylvania Department of Environmental Protection, National Fish and Wildlife Foundation, Pennsylvania Department of Conservation and Natural Resources, and Princeton Hydro.

In a press release from the Wildlands Conservancy, President Christopher Kocher, praised the collaborative effort, stating, “This yearslong effort is a win for clean water for all the communities living in connection with the Bushkill Creek. It’s a wonderful example of the power of partnerships, and what community can do for community when nonprofits, local government, and state and federal agencies pool ideas and resources to invest in our treasured natural areas.”

To celebrate this tremendous accomplishment, Wildlands Conservancy, project partners, funders, and community volunteers gathered on October 15, 2024, at Lafayette College’s Karl Stirner Arts Trail.

[gallery link="none" ids="15946,15945,15944"]

The event included a volunteer-powered wildflower planting to complete the restoration work at this site, where Dam #1, formerly owned by Lafayette College, had been removed in 2023 with the support of Princeton Hydro. Spanning 90 feet in length and standing 4 feet high, the dam had severely obstructed fish passage, contributed to local flooding, and impaired water quality over time. The college enthusiastically supported the dam's removal, dedicating substantial resources to see the project to completion.

[gallery link="none" ids="15931,15929,15934"] *Event photos provided by the Wildlands Conservancy and the Delaware River Basin Commission.

Wildlands Conservancy, a non-profit land trust based in eastern Pennsylvania, is dedicated to the restoration of degraded stream and wildlife habitats, with a primary focus on the Lehigh Valley and the extensive Lehigh River watershed, which spans 1,345 square miles, eventually merging with the Delaware River. For over a decade, Princeton Hydro has been a steadfast partner to Wildlands Conservancy in their mission, collaborating on multiple dam removal projects in the Delaware River Watershed.

Interested in learning more about how Bushkill Creek was transformed, dam by dam? Click here for an in-depth look at the journey to restore Bushkill Creek through successive dam removals. [post_title] => Update from the Field: Bushkill Creek Restored to Its Natural Free-Flowing State [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => update-from-the-field-bushkill-creek-restored-to-its-natural-free-flowing-state [to_ping] => [pinged] => [post_modified] => 2025-11-07 19:31:12 [post_modified_gmt] => 2025-11-07 19:31:12 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=15921 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 2 [filter] => raw ) [2] => WP_Post Object ( [ID] => 15468 [post_author] => 1 [post_date] => 2024-07-25 22:49:38 [post_date_gmt] => 2024-07-25 22:49:38 [post_content] =>

After 129 years, the Paulina Lake Dam in Warren County is in the final stages of demolition. This project, led by The Nature Conservancy's New Jersey Chapter, is hailed by local advocates as a significant environmental victory. The complete removal of the dam, scheduled from July through September 2024, is the second of three phases of river restoration, and signifies a major milestone in the rehabilitation of the Paulins Kill River, New Jersey’s third-largest tributary to the Delaware River.

On November 24, 2023, a crucial step in the restoration journey was taken with the first notching of the Paulina Dam. This initial step set the stage for the next phase of the dam removal, which is now in full swing. The project, a successful collaboration under the leadership of The Nature Conservancy, funded by NJDEP Division of Fish and Wildlife, and designed and implemented by Princeton Hydro and RiverLogic-Renova Joint Venture, respectively, is progressing toward its goal. The third and final phase will occur in 2025 for adaptive management to complete the finishing touches, including the installation of habitat features to further enhance the biodiversity of this river segment.


Watch the Progress Unfold

Click below to watch a new video showcasing the project's progress. The drone footage captures the project team in action, demolishing the dam, removing sediment upriver, and strategically placing rock check dam to control the flow of sediment as the removal process continues.

[embed]https://youtu.be/5VDkbvBr1z4[/embed]

Laying the Foundation for Change

Blairstown’s original power source for electricity, the Paulina Lake Dam, located in bucolic Warren County, NJ, has long posed challenges to the river’s health and surrounding communities. Originally constructed to produce hydropower, it has not functioned in that capacity for over 50 years. Its removal is crucial not only for mitigating risks to life and property but also for restoring the natural habitat for native species like brook trout and migratory fish.

Located in bucolic Warren County, New Jersey, The  Paulina Lake Dam, Blairstown’s original power source for electricity, has long posed challenges to the river’s health and, after the dam ceased its use as a power source, became a financial and safety liability to Blairstown Township. Its removal is crucial not only for mitigating risks to life and property but also for restoring the natural habitat for native species like brook trout and migratory fish.

This initiative aims to:

  • Reconnect an additional 7.6 miles of river habitat along the Paulins Kill River, adding to the 10 miles that were restored after the removal of the Columbia Lake Dam, a project led by The Nature Conservancy and designed by Princeton Hydro.
  • Improve aquatic and terrestrial connectivity, enhancing the ecosystem for fish, mussels, and other wildlife.
  • Enhance water quality and public safety, reducing the risk of an unplanned breach.
  • Boost recreation opportunities, providing a safer and more enjoyable environment for the community.

A Comprehensive Effort for Environmental Restoration

The removal of the Paulina Lake Dam is part of a larger restoration plan initiated in 2013 by The Nature Conservancy, which includes the removal of multiple dams along the Paulins Kill River, planting thousands of trees in its riparian zone, and restoration of its headwater Hyper Humus, a glacially created peat bog. This comprehensive effort, involving wetland restoration, land protection, and floodplain reforestation, aims to rejuvenate and sustain the river ecosystem.

Princeton Hydro’s President, Geoffrey M. Goll, PE, highlights the broader impact of these efforts: “The removal of Paulina Lake Dam is not just about dismantling a structure and removing a safety hazard, but paving the way for a renewed riverine landscape, where the flow of life returns to its natural course.”

As we celebrate this major milestone, we look forward to witnessing the continued transformation of the Paulins Kill. This project stands as a testament to the power of collaboration, environmental stewardship, and the unwavering dedication of communities and organizations committed to preserving and restoring our natural landscapes.

Stay tuned for more updates as we continue this exciting journey towards a restored and thriving river ecosystem this fall, and then the finishing touches in 2025! Click here to learn more about the Paulina Lake Dam removal and the broader restoration efforts.

[post_title] => Update from the Field: the Paulina Lake Dam is Coming Down! [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => update-from-the-field-the-paulina-dam-is-coming-down [to_ping] => [pinged] => [post_modified] => 2025-11-07 15:11:47 [post_modified_gmt] => 2025-11-07 15:11:47 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=15468 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 15122 [post_author] => 1 [post_date] => 2024-06-24 22:34:23 [post_date_gmt] => 2024-06-24 22:34:23 [post_content] =>

The removal of Bushkill Creek Dam #2 is now underway, marking yet another remarkable milestone in the rejuvenation of this treasured limestone stream. This achievement comes on the heels of four successfully completed dam removals since 2021, highlighting the swift progress in the revitalization efforts for Bushkill Creek.

This latest endeavor holds immense significance in facilitating the passage of migratory fish species, such as alewife and American shad, to vital upstream spawning grounds. It contributes to the recovery of ecologically-beneficial freshwater mussels and the bolstering of populations of trout and other resident fish species. And, it marks another important step in returning Bushkill Creek to its natural, free-flowing state.

During a recent site visit, Princeton Hydro President and Founding Principal Geoffrey M. Goll, P.E. took a moment to reflect on the years of hard work that have culminated in this significant milestone. Watch now:

[embed]https://youtu.be/bZs0jn6dBcQ[/embed]  

In 2022, Wildlands Conservancy enlisted the expertise of Princeton Hydro to embark on a mission to remove four dams along Bushkill Creek. The successful removal of the Crayola Dam, also known as Dam #4, marked the beginning of this transformative journey. Subsequently, in 2023, Dams #1 and #3 were dismantled. Now, we celebrate the commencement of the removal of Dam #2.

The map below shows the locations of all four dam removal locations on the Bushkill Creek:

Bushkill Creek flows 22-miles through agricultural and suburban landscape before converging with the Delaware River. Dam #2, situated upstream from the Creek’s confluence with the Delaware River, obstructed fish passage, exacerbated local flooding, and degraded water quality, much like its counterparts. Its removal represents a significant leap forward in the restoration of Bushkill Creek's ecological health.

[gallery columns="2" link="none" ids="15123,15124"]

The ongoing restoration of Bushkill Creek is a testament to the dedication of over 20 stakeholders, including, but not limited to, Wildlands Conservancy, the Delaware River Basin Commission, Lafayette College, Pennsylvania Department of Environmental Protection, National Fish and Wildlife Foundation, Pennsylvania Department of Conservation and Natural Resources, and Princeton Hydro.

Funding for the projects has stemmed from various sources, including a settlement following a fly ash spill from the Martins Creek Power Plant in 2005. This settlement, coupled with contributions from organizations like NFWF’s Delaware Watershed Conservation Fund and Northampton County’s Livable Landscapes program, propelled the initiative forward.

As we celebrate the start of removing Bushkill Creek Dam #2, we anticipate continued progress in the revitalization of this vital waterway. Each dam removed brings us closer to realizing the vision of a thriving, free-flowing Bushkill Creek, benefitting both the environment and local communities.

To read more about the dam removal successes on Bushkill Creek, click here. And, be sure to stay tuned for further updates!

Wildlands Conservancy, a non-profit land trust based in eastern Pennsylvania, is dedicated to the restoration of degraded stream and wildlife habitats, with a primary focus on the Lehigh Valley and the extensive Lehigh River watershed. Spanning 1,345 square miles, this watershed eventually merges with the Delaware River.

For over a decade, Princeton Hydro has been a steadfast partner to Wildlands Conservancy in their mission, collaborating on multiple dam removal projects in the Lehigh River Valley. With expertise in design, permitting, and oversight, Princeton Hydro has played a pivotal role in the removal of over 80 small and large dams/barriers across the Northeast.

To explore Princeton Hydro's comprehensive fish passage and dam removal engineering services, click here. For more information about Wildlands Conservancy and their conservation efforts, click here.

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Within the intricate network of aquatic ecosystems, the American shad stands as a captivating enigma. This intrigue was recently explored in a webinar hosted by The Watershed Institute titled “The Mysterious World of the American Shad and Work to Bring Them Back to Our Waterways.” Led by The Watershed Institute’s Executive Director Jim Waltman and Princeton Hydro’s Senior Technical Director in Engineering and American shad expert Dr. Clay Emerson PE, CFM, the webinar explored the complex dynamics surrounding this iconic species, including its historical significance, unique migration patterns, and conservation efforts.

As the American shad embark on their annual upstream journey for spawning, the timing is especially poignant for a closer examination of this vital species and an exploration of strategies to safeguard and revive their populations. We invite you to enjoy our blog, which encapsulates the webinar's key insights, and to watch the full recorded session made available by The Watershed Institute.


Fascinating Facts about American Shad

[caption id="attachment_14758" align="alignright" width="317"] The American shad spawning cycle and migration patterns illustrated by Delaware River Basin Commission[/caption]

American shad (Alosa sapidissima) are the largest members of the herring family. Their closest relatives are herring, sardines, and menhadens. They are an anadromous fish species, like salmon and steelhead (Oncorhynchus mykiss), that live most of their life in the ocean and migrate to freshwater rivers and streams to spawn. The American shad migration routes span vast distances, from the St. Johns River in Florida to the St. Lawrence River in Quebec, showcasing their tenacity and adaptability.

Not only do American shad undertake astonishingly long journeys to spawn, they also showcase distinctive migratory behaviors. Unlike many other anadromous species, these resilient shad can complete multiple round trips from freshwater to the ocean over their lifespan, challenging the conventional notion of 'one and done' spawning observed in Pacific salmon (Oncorhynchus) and sea lamprey (Petromyzon marinus).

Young shad will remain in the rivers where they hatched for several months. Migration out to the ocean typically occurs in late summer in the south, and early fall in the north, typically when the shad are 3-4 inches in size. Then, after 3-6 years of growth at sea, the shad migrate back to fresh water to spawn. Some shad make the journey to their spawning grounds 5-6 times over the course of their lifetime. Shad’s affinity for their birthplace adds a fascinating layer to their story. Approximately 95% of shad return to the rivers where they were hatched, with only 5% straying to unfamiliar waters to spawn.

American shad's unique hearing abilities are another noteworthy aspect. Endowed with specific biological features, shad exhibit exceptional sensitivity to water movements and noise, particularly attuned to sounds like clicks and echolocation. This acute sense plays a vital role in navigating their environment and evading predators such as dolphins.

Such intriguing characteristics make the American shad not only a vital component of aquatic ecosystems but also a subject of admiration and study among enthusiasts and conservationists alike.


Historical Significance

Throughout history, American shad have held a vital place in the cultural heritage and economic prosperity of the United States, earning them the esteemed title of "America's Founding Fish.” Within the Delaware River region, these fish were not merely sustenance but also integral to the fabric of indigenous Lenape culture. During the annual shad migration, rivers and streams overflowing with these prized fish provided essential nourishment and served as valuable fertilizer. Interestingly, in various Native American tribes, folklore depicts the shad as originating from the porcupine, likely owing to the fish's notably bony structure.

In later American history, the significance of shad persisted. Renowned painter Thomas Eakins immortalized the tradition of shad fishing in his iconic 1881 masterpiece "Shad Fishing at Gloucester on the Delaware River," while the state of Connecticut elevated the shad to the status of state fish, further cementing its place in American heritage.

[caption id="attachment_14771" align="aligncenter" width="1162"] This 1871 illustration from Granger Historical Archive depicts fishermen hauling nets of shad at Gloucester on the Delaware River.[/caption]  

Fishing for American shad was among the earliest established industries on the coast of North America, once providing abundant and affordable nutrition to the populace. However, the shad population peaked in the 1940s before experiencing a dramatic decline to its current depleted state.

Despite these challenges, the American shad perseveres as a symbol of resilience. Festivals along the Atlantic Coast, such as the Annual ShadFest in Lambertville, New Jersey, celebrate these fish while also advocating for their protection. Recognizing the historical importance of shad underscores the pressing responsibility to safeguard and preserve our natural heritage for future generations.


Challenges in American Shad Restoration

[caption id="attachment_14759" align="alignright" width="347"] An American shad swimming and feeding in the Delaware River[/caption]

The construction of dams, historic overfishing, and pollution have all played significant roles in the decline of American shad populations.

Dams along the East Coast block access to vital spawning grounds. Currently, a staggering 40% of American shad habitat is obstructed by these barriers, resulting in the loss of more than a third of the population. By removing outdated dams that have outlived their usefulness, we not only improve water quality and natural habitat for myriad species but also reconnect shad to their historic spawning grounds.

Additionally, shad fall victim to inadvertent bycatch in various ocean fisheries. Pollution in our rivers and water quality issues emerge as another critical concern along with fluctuating water temperatures and dissolved oxygen levels that disrupt shad behavior and crucial life cycle events such as migration and spawning. Compounding these issues are the menacing presence of invasive species, which outpace shad in numbers and deplete food resources, posing a significant obstacle to their recovery efforts.

Amidst these challenges, there is hope. River restoration efforts, dam removals, and fish passage projects throughout the East Coast stand as beacons of progress.


Conservation Efforts

Removing obsolete dams, culverts, and other man-made barriers; the implementation of fish passage projects; and river habitat restoration initiatives have shown promising results in directly aiding shad and other migratory aquatic species populations. Highlighted below are a few examples of dam removal initiatives that immediately yielded positive results:

Paulins Kill River

[caption id="attachment_14773" align="aligncenter" width="1720"] Columbia dam pre-removal (June 2018) vs one year after the dam removal (June 2019). Today, the river is healthy and free flowing.(Photo Credit: Columbia Dam Then and Now, Jeff Burian/The Nature Conservancy)[/caption]  

The Nature Conservancy in New Jersey and Princeton Hydro are leading the removal of three outdated dams on the Paulins Kill River: the Columbia Lake Main and Remnant Dams (completed 2019), the County Line Dam (completed 2021), and Paulina Dam (slated for completion 2024). This collaborative effort will reconnect 45 miles of mainstream and tributaries for migratory fish species like American shad. The Columbia Lake Dam removal, New Jersey's largest to date, began in July 2018 and showed promising results even before 100% completion. By April 2019, American shad were spotted 10 miles upstream from the former dam site for the first time in over a century, showcasing the resilience of this incredible species and the success of conservation initiatives.


Musconetcong River

[caption id="attachment_11894" align="aligncenter" width="1720"] Photos by MWA[/caption]  

In November 2016, the Musconetcong Watershed Association (MWA) and Princeton Hydro completed the Hughesville Dam Removal, opening up six miles of the Musconetcong to migratory fish. In the Spring of 2017, schools of American shad were observed above the dam, five miles from the river's confluence with the Delaware River. After an absence of over 250 years, American shad made a triumphant return to the Musconetcong River sparking hope for the future.


Shad serve as a crucial benchmark species, offering valuable insights into the ecological health and diversity of our waterways. Conservation endeavors that facilitate the resurgence of the American shad not only represent a thrilling triumph but also stand as proof-positive of our capacity to assist migratory fish in reclaiming their natural habitats. In doing so, we safeguard their future and preserve the places they call home.

By understanding the biology, historical significance, and primary challenges of the American shad, we can work towards sustainable solutions that benefit both shad populations and the broader ecosystem. We invite you to delve deeper into the fascinating world of American shad by watching the full webinar:  

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The Paulins Kill River, New Jersey’s third largest tributary to the Delaware River, recently marked a significant milestone in its journey to restoration. On November 24, a crucial step was taken with the notching of the Paulina Lake Dam, signaling a pivotal moment in the effort to return the river to its natural state. This initiative, led by The Nature Conservancy (TNC) and supported by a collaborative effort among several organizations, aims to restore the Paulins Kill River ecosystem, improve water quality, and allow native aquatic species to migrate freely.

[caption id="attachment_13988" align="aligncenter" width="2048"] November 24, 2023, the first notch is made in the Paulina Lake Dam. By TNC photographer David Pexton.[/caption]

Understanding the Project

[caption id="attachment_13992" align="alignleft" width="431"] Photo by David Pexton of TNC.[/caption]

Located in Blairstown Township, Warren County, the Paulina Lake Dam has posed challenges to both the river's health and surrounding communities. It was originally constructed 128 years ago to produce hydropower, but has not functioned in that capacity for more than 50 years. Delaware River tributaries do not have the necessary size or flow to meet even a fraction of modern energy needs.

The 13-foot-high, 207-foot-long timber crib, rock-filled structure is classified as a Class II, Significant Hazard Dam due to its proximity to the Township of Blairstown. Its removal or rehabilitation became necessary to mitigate risks to life and property. Additionally, the dam has impeded fish passage along the Paulins Kill River, impacting the habitat for native brook trout and migratory species.

The dam removal and subsequent bank stabilization aims to reconnect over 7.6 miles of mainstream and tributary habitat along the river, and improve aquatic and terrestrial connectivity, improve surface water quality, enhance recreation and public safety, and eliminate the risk of a potential unplanned breach. The removal of the dam will also reconnect upstream and downstream populations of the endangered dwarf wedge and triangle floater mussels while increasing river ecology and public recreation.

Spearheaded by TNC in partnership with Blairstown Township, New Jersey Department of Environmental Protection’s Office of Natural Resource Restoration and Division of Fish and Wildlife, the U.S. Fish and Wildlife Service, Princeton Hydro, and Riverlogic-Renova Joint Venture, the project received funding through grants to support the removal of the Paulina Lake Dam. The Office of Natural Resources Revenue (ONRR) 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.

[caption id="attachment_13996" align="alignright" width="1108"] On November 27, 2023, members from the indie pop band Nation of Language visited the site to witness the dam removal team's progress.[/caption]

Notching and Deconstruction

TNC recently completed preliminary notching of the 128-year-old Paulina Lake Dam. From November 24 through December 1, contractors from the Riverlogic-Renova Joint Venture worked in the river using heavy equipment to successfully remove a 40-foot long, six-foot high section of the structure, enabling a controlled release of the water impounded behind it.

Click below to watch as the first notch is made: [embed]https://youtu.be/XN1z2VlLeZI[/embed]

Notching is performed to dewater gradually, preventing large amounts of sediment from flowing downstream all at once and potentially harming habitat. The gradual deconstruction ensures the river's stability and minimizes environmental disruption. The project team made subsequent reductions of the dam's height by one foot each day, totaling a six-foot reduction. Complete removal of the dam is slated for July through September of 2024.

[gallery link="none" size="medium" ids="13997,13991,13989"]

Reporters from WFMZ 69 News visited the dam removal site to witness the first notch and talk with State Director of TNC in New Jersey Dr. Barbara Brummer, Blairstown Mayor Rob Moorhead, Director of Freshwater Programs at TNC in New Jersey Beth Styler Barry.

“Rivers remember,” said Beth Styler Barry, Director of Freshwater Programs at The Nature Conservancy in New Jersey. “The instant the first notch was made we could already see the Paulins Kill transforming into a more natural shape. Now with six vertical feet taken out, the water that has been stagnant for more than a century is flowing, cooling and aerating, and the natural floodplains are once again exposed and ready to revegetate.”

Click below to watch the full interview:

 

Princeton Hydro, contracted by TNC to provide site investigation, engineering design, permitting, and construction oversight services for the dam removal, has been working closely with Riverlogic-Renova Joint Venture to complete the deconstruction process.

"The first day of dam demolition is always exciting; seeing the river flowing through the breached Paulina Lake Dam after the first notch was very rewarding," said Paulo Rodriguez Heyman, Managing Member of the Riverlogic-Renova Joint Venture, the team leading the construction for the project. "Removing a high-hazard dam is challenging and requires the unique expertise of working in a dynamic river system. We are honored to be part of this collaborative team."


Embracing the Future

The removal of the Paulina Lake Dam stands as one integral facet of a larger restoration plan initiated in 2013, envisioning the removal of multiple dams along the Paulins Kill River. In removing the Paulina Lake Dam, the downstream-most dam on the Paulins Kill, TNC continues to build upon previous watershed-wide restoration activities that includes removing four dams: the Columbia Lake Main and Remnant Dams (2019), the County Line Dam (2021), and now the Paulina Lake Dam.

This multi-pronged effort includes wetland restoration, land protection, and floodplain reforestation—with more than 60,000 trees planted to date throughout 130 acres of floodplain. TNC has executed a 10-year “measures and monitoring” program, which began in 2016, to track conservation successes. This comprehensive effort brings hope for a rejuvenated and thriving river environment.

“The removal of Paulina Lake Dam is not just about dismantling a structure and removing a safety hazard, but paving the way for a renewed riverine landscape, where the flow of life returns to its natural course,” said Geoffrey M. Goll, PE, President of Princeton Hydro and Engineer-of-Record for the Paulina Dam removal project. “As a mission driven firm, we seek out projects that will have a positive ecological impact. We are proud to share that three of the dam removals that we designed on the Paulins Kill - Paulina Lake Dam, Columbia Lake Dam, and County Line Dam - will reconnect 45 miles of mainstem and tributaries for targeted migratory fish species like American shad, American eel, and sea lamprey.”

Resident fish and other aquatic organisms including mussels and trout will also benefit from habitat and water quality improvements, as will birds, pollinators and land-based animals that rely on the river for survival. [caption id="attachment_14026" align="aligncenter" width="697"] Left to Right: Geoffrey M. Goll, PE of Princeton Hydro; Beth Styler Barry of TNC; and Paulo Rodriguez Heyman of Riverlogic-Renova Joint Venture.[/caption]  

The Paulina Lake Dam Removal will be the final step in the TNC-led restoration of the lands and waters of the Paulins Kill.

[embed]https://youtu.be/jo13xTChKLE[/embed]

As the restoration journey continues, it stands as a testament to the power of collaboration, environmental stewardship, and the dedication of communities and organizations striving to preserve and restore our natural landscapes.

Stay tuned for further updates on the incredible transformation of the Paulins Kill River!

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The removal of Beatty's Mill Dam stands as a pivotal moment in the conservation efforts along the Musconetcong River. This critical initiative, spearheaded by the Musconetcong Watershed Association (MWA), Washington Township, and the Town of Hackettstown in collaboration with Princeton Hydro and RiverLogic Solutions, marks a significant stride towards rejuvenating the river's natural ecosystem and addressing long-standing concerns regarding flood mitigation and habitat preservation.

[caption id="attachment_13929" align="aligncenter" width="763"] Photo taken November 12, 2023.[/caption]

History of the Beatty’s Mill Dam

Beatty's Mill Dam straddles the border between Warren and Morris Counties in Hackettstown and Washington Township, New Jersey.  It is a 6-foot-high stone masonry, concrete, and earth embankment dam that was built in the 18th century and has been non-functional for decades.

[caption id="attachment_13968" align="alignright" width="419"] Photo of Beatty's Mill Dam (pre-removal) taken from upstream with the East Avenue bridge in the background[/caption]

Beatty’s Mill Dam is a low-head dam, which means it was not built to protect communities from flooding and can make flooding worse in some cases. Hackettstown and Washington Township are also more susceptible to flooding and erosion due to the high percentage of impervious surfaces, like roads and parking lots, which cause higher flows of stormwater runoff.

A dam safety report from 1981 shows that the dam had been breached on the eastern end. The breach caused a hairpin turn where the river is diverted sharply to the east then back to the west before flowing under the East Avenue bridge. Over time, this created erosive conditions at the upstream side of the bridge and roadbed, threatening the integrity of the infrastructure. Additionally, extensive alteration of the floodplain occurred upstream of the dam, including an elevated earthen berm along the left bank, and general land disturbance in both upland and wetlands.

The removal of the dam not only addresses the structural concerns but also holds the promise of extensive environmental improvements. By eradicating barriers to the Musconetcong River's natural flow, restoring the floodplain, and implementing strategies to curb stormwater runoff, this initiative aims to mitigate flooding, promote water quality, and foster a thriving habitat for aquatic organisms including indigenous species like the Eastern Brook Trout and American Eel.


Removing the Dam

With funding from the Highlands Council, Princeton Hydro was contracted in 2019 by Washington Township to complete a water quality assessment, hydrologic and hydraulic analysis, and functional value stream assessment of reaches of the Musconetcong River that encompassed the Beatty’s Mill site (and the downstream Newburgh Dam site). Following the New Jersey Highlands Water Protection and Planning Council guidance, Princeton Hydro assessed and rated the river reaches on five functional values: channel integrity, habitat, water quality, temperature moderation, and public use. The Beatty’s Mill Dam, floodplain encroachment, narrow riparian buffers, and non-native riparian vegetation were the primary sources of impact to the functional values.

Subsequently, Princeton Hydro was contracted by MWA to complete a site investigation, wetland delineation, topographic survey, and preliminary (60%) engineering design for dam removal. Preliminary plans were reviewed by Washington Township and the Town of Hackettstown. In 2023, Princeton Hydro completed the final engineering design, hydrologic and hydraulic modeling, and permitting for the removal of Beatty’s Mill Dam and restoration of the floodplain and provided engineering oversight during construction.

[gallery link="none" columns="2" ids="13938,13939"]  

The removal of Beatty’s Mill Dam was officially completed the week of November 13, 2023!

Princeton Hydro assisted in the removal and restoration, providing engineering plans and project management support. With the dam removed, 2.5 acres of flood plain have been restored; 0.15 mile of stream bank have been stabilized; 0.15 mile of stream bed has been rehabilitated; and total suspended solids in the water have been reduced by 20%.

Michael Allers, Princeton Hydro Restoration Ecologist and licensed FAA-Certified Commercial Drone Pilot, captured these aerial images of the completed project site:

[gallery link="none" columns="4" ids="13934,13933,13932,13931"]

It is projected that there will be significant improvement to the five aforementioned functional values, increased fish passage, enhanced hydraulic conditions at the East Avenue bridge as well as improvements to the river’s pH, temperature, and dissolved oxygen levels.

Removing the dam also supports conformance with the Highlands Regional Master Plan, which is intended to protect, preserve, and enhance precious water resources within the Highlands Region. The project work also includes the restoration of the damaged floodplain, stream banks, and stream bed by planting trees, building up the banks with rocks, and allowing the river to return to its natural flowing channel.


Looking Ahead

This project’s significance extends beyond the immediate environmental impact. Funding from sources like the National Fish and Wildlife Foundation under the Delaware Watershed Conservation Fund and New Jersey’s Highlands Council, along with corporate contributions, underscores its potential to serve as a model for similar restoration projects across the Delaware River Watershed. Such initiatives not only enhance aquatic habitats but also bolster community resilience against flooding and elevate public awareness regarding watershed conservation.

The vision for this restoration effort reflects a collective commitment to revitalize river ecosystems, not just for the immediate region but as part of a broader strategy for conservation. The Beatty's Mill Dam marks the MWA's sixth dam removed on the Musconetcong River since 2008, but it is far from the last. This project aims to set a precedent for sustainable river management and ecosystem preservation.

The removal of Beatty's Mill Dam represents a milestone in the ongoing efforts to restore the Musconetcong River's ecological balance and underscores the collaborative spirit between MWA, local municipalities, various stakeholders, and Princeton Hydro. It serves as a testament to the potential of concerted conservation endeavors to restore the vitality of our waterways and safeguard the natural heritage for generations to come.


The Musconetcong Watershed Association (MWA) is an independent, nonprofit organization dedicated to protecting and improving the quality of the Musconetcong River and its watershed, including its natural and cultural resources. Members of the organization are part of a network of individuals, families, and companies that care about the Musconetcong River and its watershed, and are dedicated to improving the watershed resources through public education and awareness programs, river water quality monitoring, promotion of sustainable land management practices, and community involvement. Click here to learn more.

Princeton Hydro has been working with MWA in the areas of river restoration, dam removal, and engineering consulting since 2003. Click here to read our Client Spotlight blog featuring MWA’s Executive Director Cindy Joerger and Communications Coordinator Karen Doerfer.

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An extraordinary effort is underway in the Hudson River Valley—the removal of the Maiden Lane Dam. The towering 25-foot concrete structure, originally built for aesthetic purposes on a tributary to the Hudson River, has been impairing aquatic life and causing an array of negative environmental impacts since its construction in the early 1900s. Now, it is the focus of a project that promises to restore vital aquatic habitats.

Join us as we take a deeper look at the Maiden Lane Dam Removal project, an initiative that has been in the planning phase for nearly five years.


Maiden Lane Dam

Located in the Town of Cortlandt on Furnace Brook, a tributary of the Hudson River, the Maiden Lane Dam was originally built by the former owners of McAndrews Estate. Unlike many dams throughout the country constructed with the primary goals of flood control, hydroelectric power, agricultural irrigation, or navigation of boats, the Maiden Lane Dam was built for aesthetic purposes. Yet the dam's impact extended well beyond its appearance.

The Maiden Lane Dam is the very first dam that fish and aquatic species encounter on Furnance Brook while attempting to travel up the Hudson River to reach foraging habitats and ancestral spawning grounds. The antiquated, unused dam poses a variety of risks to the wildlife restricted by the dam, people who live and recreate near the dam, and the environment surrounding the dam.


The Dam Removal Project Takes Shape

McAndrews Estate, along with the dam, was abandoned in the 1960s, and subsequently, Westchester County Parks assumed control of it. Shortly afterwards, the property was condemned.

In 2021, Princeton Hydro secured a contract with Westchester County to develop and finalize the dam removal engineering plans, secure permitting, and facilitate construction bid procurement. The project work also entailed collecting and analyzing sediment samples, conducting geomorphic assessments, and completing an in-depth hydraulic and hydrologic analysis focusing on potential flooding impacts. The collaboration with key stakeholders, including NYSDEC, Westchester County, and the Town of Cortlandt, ensured the feasibility of this ambitious dam removal endeavor.

The collaboration and careful planning set the stage for the much-anticipated removal of the Maiden Lane Dam.


A Hopeful Future for Hudson River Valley

The significance of this project cannot be overstated. Beyond its historical and ecological significance, the Maiden Lane Dam removal will reconnect approximately 1.5 miles of habitat for fish and other aquatic species. It represents a promising chapter in the ongoing efforts to revitalize Hudson River Valley streams and conserve the region's diverse fish and wildlife.

As we eagerly await the completion of the Maiden Lane Dam removal, the vision of restored aquatic habitats and thriving ecosystems shines brightly on the horizon. The journey of the Maiden Lane Dam Removal project is a testament to dedication, collaboration, and the unwavering commitment to the preservation of our natural environment.


Keep the Dam Removal Conversations Flowing

Princeton Hydro team members Jake Dittes, PE and Duncan Simpson, PWS presented on Hudson Valley Dam removal during the 2023 National Stream Restoration Conference, hosted by the Resource Institute, a nonprofit organization dedicated to the restoration of America's precious waterways. The event, themed "Stream Restoration 2023: Finding Common Ground,” served as an inspiring backdrop for the broader narrative of stream restoration, showcasing the importance of projects like the Maiden Lane Dam removal in preserving our natural treasures.

The Maiden Lane Dam Removal is part of a larger effort, led by Riverkeeper, to restore migratory fish pathways and fisheries in the Hudson River Watershed.

Princeton Hydro has designed, permitted, and/or overseen the removal of 80+ small and large dams in the Northeast. To learn more about fish passage and dam removal efforts in the Hudson River Valley, click here. To learn more about our engineering services, click here.

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In a momentous occasion for environmental conservation, a dam removal on Bushkill Creek is underway, building upon a new era for this cherished limestone stream.

This dam removal marks another important milestone in restoring Bushkill Creek back to its natural, free-flowing state; connecting migratory fish species like alewife and American shad with upstream spawning grounds; and helping to revitalize ecologically-beneficial freshwater mussels colonies and populations of trout and other residential fish species.


Freeing Bushkill Creek One Dam at a Time

Bushkill Creek begins at the foot of Blue Mountain in Bushkill Township, Pennsylvania and flows 22 miles before its confluence with the Delaware River. The limestone stream flows through agricultural and suburban areas, as well as Easton, and supports a large wild brown trout population. It is designated as a “high quality, cold-water fishery” and treasured by anglers and the surrounding community as an important resource in an urban environment.

In 2022, Wildlands Conservancy contracted Princeton Hydro to design, permit, and oversee construction for the removal of four dams along Bushkill Creek. The Crayola Dam, also called Dam #4, was the first of the four dam removal projects to be completed.

The map below shows the location of the next three Bushkill Creek dams being removed:

[caption id="attachment_13253" align="aligncenter" width="571"] Created by Wildlands Conservancy, Contributed by Kurt Bresswein of The Star Ledger[/caption]  

The demolition and removal of Dam #1 commenced on July 7, 2023 and is scheduled for completion in August. The site labeled as Dam #3 is scheduled for demolition and removal later this year. And, the site labeled as Dam #2, is scheduled for removal in the summer of 2024.

Removing nonfunctional, outdated dams from the Bushkill and allowing the creek to return to a natural, free-flowing state will have myriad ecological benefits.


Removing the Bushkill’s First Barrier

Dam #1, the first barrier on the Bushkill, is located directly upstream from the Creek’s confluence with the Delaware River. Previous to this removal process, Dam #1 was the upstream limit for migratory fish like alewife, striped bass, and shad.

Dam #1 is owned by Lafayette College in Easton, Pennsylvania. It spans an impressive length of 90 feet, width of 14 feet, and stands 4-feet high. Having been constructed in 1793, the dam had fallen into a state of disrepair, with crumbling concrete impacting the integrity of the streambank retaining wall. Consequently, the dam and associated impoundment have had detrimental effects on the creek's ecosystem, obstructing fish passage, exacerbating local flooding, and degrading water quality. Professors and students of the College have tried for years to effectuate Bushkill Creek dam removals to improve the aquatic environment.

[caption id="attachment_13174" align="aligncenter" width="694"] View of the Bushkill Dam #1, located in the City of Easton, before the construction crew takes the first notch.[/caption]   [gallery link="none" columns="2" ids="13188,13187"]

By removing the dam, the project team aims to improve water quality, restore the creek back to its natural flowing state, reconnect river habitats that benefit fish and wildlife, and significantly increase biodiversity for the surrounding watershed. The project work also includes stabilizing the streambank, expanding riparian buffers, planting native trees and shrubs to filter runoff, and installing in-stream structures to restore fish habitat, which has numerous and far-reaching ecological benefits. It is important to note that the project's scope involves minimal disturbance, impacting less than one acre of land surrounding the dam.

Watch as the construction team makes the first notch in Dam #1: [embed]https://youtu.be/73Jrssb75pE[/embed] The removal of this specific dam holds profound promise, heralding a transformative era for the ecological well-being of Bushkill Creek. Signs of improvement were immediately visible as the construction team worked to notch out Dam #1: [gallery columns="2" link="none" ids="13177,13171"] [caption id="attachment_13180" align="aligncenter" width="837"] This photo taken on July 12, 2023 (just 5 days after the first notch) shows great progress being made on the Bushkill Dam removal effort.[/caption] [caption id="attachment_13265" align="aligncenter" width="1245"] This photo was taken on July 19, 2023, just 12 days after the first notch.[/caption]

Collaborative Efforts Yield Success

The continued effort to restore Bushkill Creek with the removal of Barrier #1, which has been 10-years in the making, serves as a testament to the unwavering dedication displayed by a diverse array of 20+ stakeholders, including Delaware River Basin Commission, Lafayette College, Pennsylvania Department of Environmental Protection, National Fish and Wildlife Foundation (NFWF), Pennsylvania Department of Conservation and Natural Resources, and Princeton Hydro.

According to the Wildlands Conservancy, the initial natural resource damage assessment funding came following a fly ash spill from the Martins Creek Power Plant in 2005. The settlement, which was reached in 2016, totaled $1.3 million, with $902,150 going to the Delaware River Basin Commission for dam removal projects and $50,000 going to the Commission to manage mussel restoration. Additional funding for the overall project came from NFWF's Delaware Watershed Conservation Fund ($2,049,200), and Northampton County's Livable Landscapes program ($100,000).


Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of 80+ small and large dams in the Northeast. For over a decade, Princeton Hydro has partnered with Wildlands Conservancy to remove dams in the Lehigh River Valley. To learn more about our fish passage and dam removal engineering services, click here. To learn more about Wildlands Conservancy, click here.

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The Horseshoe Mill Dam, built in 1827, served as the first barrier to fish passage on the Weweantic River in Wareham, Massachusetts. For over 150 years, migratory fish were unable to reach their breeding grounds upstream due to this structure. However, thanks to the efforts of the Buzzards Bay Coalition and its project partners, the dam was successfully removed between December 2019 and February 2021. As early as April 2021, migratory fish were seen swimming unimpeded from Buzzards Bay to lay their eggs in freshwater upstream. A true success story!

This blog explores the Horseshoe Mill Dam removal project and celebrates the significant milestone in the recovery of fish populations and the restoration of ecological processes in the Weweantic River.


A Brief History

The Weweantic River winds its way through the picturesque landscapes of southeastern Massachusetts, spanning a length of 17.0 miles. This land is the traditional territory of the Wampanoag/Wôpanâak tribes. Derived from the Wampanoag language, Weweantic means "crooked" or "wandering stream."

Originating from the wetlands in Carver, the river flows in a southerly direction meandering through swampy birch and maple forests in Middleborough and Rochester. Eventually, it empties into a Buzzards Bay estuary near the mouth of the Sippican River in Wareham. The river's watershed covers approximately 18,000 acres, with numerous cranberry bogs situated in its upper sections.

Although the Weweantic River historically teemed with fish, the presence of the Horseshoe Mill Dam posed an obstacle to fish passage. The dam, spanning the Weweantic River at the head-of-tide, was built in 1827 to support a metal forge mill. Although it was once part of the infrastructure that supported Wareham’s economy, it had been decommissioned and left crumbling for decades. The defunct dam restricted to tidal inundation, hindered the migration of important fish species, and impacted riverine ecological processes.


Ecological Importance of the Weweantic River

The Weweantic River is the largest tributary to Buzzards Bay and provides 20 percent of all freshwater flow into Buzzards Bay. The meeting of salinity and nutrients through the tidal flow creates a vibrant ecosystem. It supports diverse communities of wetland species and a variety of non-migratory and migratory fish species, including river herring, white perch, and American eel. It is also home to the southernmost population of rainbow smelt in the United States, marking a significant change from a century ago when rainbow smelt were found as far south as the Chesapeake Bay. In the 1960s, smelt populations were even present in the Hudson River in New York.

Further highlighting the ecological significance of the Weweantic River and its surrounding watershed are the unique tidal freshwater wetland plant communities. The wetland areas surrounding the Horseshoe Mill Dam site contained two rare wetland plants, Parker's Pipewort (Eriocaulon parkeri) and Pygmyweed (Crassula aquatica), both of which are designated as priority habitats for rare species.

[gallery columns="2" size="medium" link="none" ids="14279,14281"]

Additionally, situated along the shore of Buzzards Bay and the Weweantic River is the Cromeset Neck & Mark's Cove Marsh Wildlife Sanctuary. The 47-acre wildlife sanctuary consists of three separate parcels within one mile of each other. Salt marsh comprises most of the wildlife sanctuary, and the property also contains approximately six contiguous acres of coastal woodland.


Restoration Efforts and Project Phases

The Horseshoe Mill Dam removal project involved several phases to achieve its restoration goals.

An inspection of the dam, conducted in 2009, rated its condition as unsatisfactory and noted significant concrete deterioration and erosion. The dam also included a former concrete-walled mill race that was in a state of disrepair, with collapsed walls and obstructed channels. The Buzzards Bay Coalition acquired the 10-acre Horseshoe Mill Dam property in 2012 to preserve it, provide public access, and pursue river restoration.

In 2016, the Buzzards Bay Coalition contracted Princeton Hydro to provide an Alternatives Analysis for the Weweantic River restoration project and a Fish Passage Feasibility Study for the dam. The analysis included a thorough site investigation, historical data review, sediment evaluation, hydrologic and hydraulic analysis, and ecological assessment. The five options considered in the analysis were:

  1. No action;
  2. Structural dam repair with a fish ladder;
  3. Dam lowering with a nature-like fishway;
  4. Partial dam removal with an extended riffle; or
  5. Complete dam removal.

The analysis ultimately helped the Buzzards Bay Coalition determine that a complete dam removal offered the most favorable ecological and economic outcomes.

[caption id="attachment_12821" align="aligncenter" width="789"] The removal of Horseshoe Mill Dam commences on a snowy day in December 2019.[/caption]  

Princeton Hydro, contracted by the Buzzards Bay Coalition, provided site investigation, engineering design, permitting, and construction oversight services for the dam removal. With funding from the Bouchard 120 Natural Resource Damage Trustee Council and collaboration with various agencies, including the U.S. Fish and Wildlife Service and NOAA, the dam removal commenced in December 2019 and was successfully completed in early 2021. Just months later in April 2021, for the first time in 150+ years, migratory fish were once again spotted swimming unimpeded from Buzzards Bay to lay their eggs in freshwater upstream.

Since the completion of the dam removal, Buzzards Bay Coalition Restoration Ecologist Sara da Silva Quintal has been consistently visiting the site and monitoring the positive changes taking place. Her observations include vegetation changes, signs of migratory fish spawning, and the geomorphic evolution of the landscape. She shared a series of Nearmap images that demonstrate how the landscape is positively adjusting to the barrier removal:


Celebrating Conservation Success

The completion of the Horseshoe Mill Dam removal project marks a significant achievement in the restoration of fish passage and the preservation of ecological function in the Weweantic River. Through the collaborative efforts of the Buzzards Bay Coalition, government agencies, and project partners, migratory fish can now freely swim upstream to their breeding grounds.

The restoration effort rejuvenated more than three miles of the Weweantic River and restored migratory fish passage. The dam removal enhanced riverine, wetland, and tidal habitat critical to a diverse group of aquatic, wildlife and plant species. It allowed for the natural extension of upriver habitat for two rare tidal plant species, ensuring their long-term survival. The restoration work also enhanced public access to the area by increasing walking trails and constructing canoe/kayak launches, promoting recreational opportunities, and fostering a deeper connection between people and the river.

[caption id="attachment_12824" align="aligncenter" width="710"] Photo taken on November 2022[/caption]  

In an article written by Kasey Silvia in November 2021, the Vice President for Watershed Protection at Buzzards Bay Coalition, Brendan Annett, was quoted as saying, “Removing this dam has immediately improved the natural functions of the Weweantic, undoing many years of environmental damage and it has already begun to bring the river back to life.”

The success of this project serves as a testament to the importance of collaborative conservation efforts in safeguarding and restoring our natural resources.


Princeton Hydro is a leader in dam removal in the Northeast, having designed and removed 80 dams. To view additional dam removal projects that we have completed, click here. For more information on our dam removal services, contact us here. [post_title] => Restoring Fish Passage and Ecological Function: The Horseshoe Mill Dam Removal Project [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => horseshoe-mill-dam-removal-project [to_ping] => [pinged] => [post_modified] => 2024-01-18 03:08:36 [post_modified_gmt] => 2024-01-18 03:08:36 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=12814 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) ) [post_count] => 10 [current_post] => -1 [before_loop] => 1 [in_the_loop] => [post] => WP_Post Object ( [ID] => 19057 [post_author] => 1 [post_date] => 2026-01-28 15:50:41 [post_date_gmt] => 2026-01-28 15:50:41 [post_content] =>

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.

[caption id="attachment_19094" align="aligncenter" width="800"] Paulina Lake Dam aerial view prior to removal. Photo by Jim Wright/TNC/LightHawk[/caption]  

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: [gallery link="none" size="medium" ids="19109,19110,19111"]

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: [embed]https://www.youtube.com/watch?v=T6dQRRU5DCE[/embed]

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. [post_title] => Then and Now: Paulina Lake Dam Removal [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => then-and-now-paulina-lake-dam-removal [to_ping] => [pinged] => [post_modified] => 2026-01-28 15:59:36 [post_modified_gmt] => 2026-01-28 15:59:36 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=19057 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [comment_count] => 0 [current_comment] => -1 [found_posts] => 32 [max_num_pages] => 4 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => [is_tag] => 1 [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_favicon] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => a974798dee0b66f95fb5985f8351a0e4 [query_vars_changed:WP_Query:private] => 1 [thumbnails_cached] => [allow_query_attachment_by_filename:protected] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) [query_cache_key:WP_Query:private] => wp_query:b77678c9a71284625ea0c9b198343101 )

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