We’re committed to improving our ecosystems, quality of life, and communities for the better.
Our passion and commitment to the integration of innovative science and engineering drive us to exceed on behalf of every client.
WP_Query Object ( [query] => Array ( [category_name] => landscape-architecture ) [query_vars] => Array ( [category_name] => landscape-architecture [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [tag] => [cat] => 1887 [tag_id] => [author] => [author_name] => [feed] => [tb] => [paged] => 1 [meta_key] => [meta_value] => [preview] => [s] => [sentence] => [title] => [fields] => all [menu_order] => [embed] => [category__in] => Array ( [0] => 40 ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) [search_columns] => Array ( ) [ignore_sticky_posts] => [suppress_filters] => [cache_results] => 1 [update_post_term_cache] => 1 [update_menu_item_cache] => [lazy_load_term_meta] => 1 [update_post_meta_cache] => 1 [post_type] => [posts_per_page] => 10 [nopaging] => [comments_per_page] => 5 [no_found_rows] => [order] => DESC ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( [0] => Array ( [taxonomy] => category [terms] => Array ( [0] => landscape-architecture ) [field] => slug [operator] => IN [include_children] => 1 ) [1] => Array ( [taxonomy] => category [terms] => Array ( [0] => 40 ) [field] => term_id [operator] => IN [include_children] => ) ) [relation] => AND [table_aliases:protected] => Array ( [0] => ph_term_relationships [1] => tt1 ) [queried_terms] => Array ( [category] => Array ( [terms] => Array ( [0] => landscape-architecture ) [field] => slug ) ) [primary_table] => ph_posts [primary_id_column] => ID ) [meta_query] => WP_Meta_Query Object ( [queries] => Array ( ) [relation] => [meta_table] => [meta_id_column] => [primary_table] => [primary_id_column] => [table_aliases:protected] => Array ( ) [clauses:protected] => Array ( ) [has_or_relation:protected] => ) [date_query] => [queried_object] => WP_Term Object ( [term_id] => 1887 [name] => Landscape Architecture [slug] => landscape-architecture [term_group] => 0 [term_taxonomy_id] => 1887 [taxonomy] => category [description] => [parent] => 0 [count] => 13 [filter] => raw [term_order] => 0 [cat_ID] => 1887 [category_count] => 13 [category_description] => [cat_name] => Landscape Architecture [category_nicename] => landscape-architecture [category_parent] => 0 ) [queried_object_id] => 1887 [request] => SELECT SQL_CALC_FOUND_ROWS ph_posts.ID FROM ph_posts LEFT JOIN ph_term_relationships ON (ph_posts.ID = ph_term_relationships.object_id) LEFT JOIN ph_term_relationships AS tt1 ON (ph_posts.ID = tt1.object_id) WHERE 1=1 AND ( ph_term_relationships.term_taxonomy_id IN (1887) AND tt1.term_taxonomy_id IN (40) ) AND ((ph_posts.post_type = 'post' AND (ph_posts.post_status = 'publish' OR ph_posts.post_status = 'acf-disabled'))) GROUP BY ph_posts.ID ORDER BY ph_posts.menu_order, ph_posts.post_date DESC LIMIT 0, 10 [posts] => Array ( [0] => WP_Post Object ( [ID] => 19515 [post_author] => 1 [post_date] => 2026-04-06 19:40:48 [post_date_gmt] => 2026-04-06 19:40:48 [post_content] => In developed watersheds, stormwater behavior is fundamentally altered by impervious surfaces and aging infrastructure, which can result in erosion, localized flooding, and nutrient pollution in surrounding waterways. These challenges rarely have simple or universal solutions, particularly in communities where natural systems, critical infrastructure, and public safety intersect within constrained landscapes. How practitioners navigate these challenges and decide when to rely on green, gray, or hybrid stormwater solutions was the focus of a recent educational session at The Watershed Institute’s 9th Annual New Jersey Watershed Conference. The session, led by Princeton Hydro Water Resources Engineer Sean Walsh, PE and Landscape Architect Jamie Feinstein, RLA, alongside the Mayor of Lambertville (NJ) Andrew Nowick, explored how context‑driven design informs effective stormwater and erosion control strategies in developed environments. Drawing from three real‑world case studies, the presenters examined how surrounding land use, physical constraints, risk tolerance, and stakeholder priorities shape decision‑making and why the most effective stormwater solutions are rarely one‑size‑fits‑all. This blog summarizes key lessons from that presentation, highlighting how site‑specific conditions ultimately determine whether green infrastructure, gray infrastructure, or a hybrid approach is the most appropriate tool for managing erosion, sediment, and flooding in settings shaped by competing land‑use and infrastructure demands. Understanding the Tradeoffs: Green vs. Gray Infrastructure Green infrastructure is designed to manage stormwater by mimicking natural hydrologic and geomorphic processes that are often altered or suppressed by development. Practices such as floodplain reconnection, step pools, riparian buffers, naturalized detention basins, and restored stream channels slow runoff, promote infiltration, and moderate sediment transport, while also improving water quality. When implemented at appropriate scales, these approaches can increase green space within built and urban environments, enhance habitat and biodiversity, and enrich the surrounding landscape by integrating stormwater management with ecological and recreational functions. However, the feasibility and performance of green infrastructure are highly dependent on site‑specific conditions, including available space, slope, and flow regimes, which are frequently constrained in urban environments. [gallery link="none" columns="2" size="full" ids="19522,19523"] Gray infrastructure, by contrast, is designed to prioritize conveyance, control, and predictability. Systems such as pipes, culverts, and engineered structures are well‑suited to managing high‑capacity flow rates, centralizing stormwater runoff, and conveying water safely through constrained environments. These approaches typically require smaller physical footprints than nature‑based alternatives and often involve lower long‑term maintenance demands. In developed settings, gray infrastructure can also provide critical structural support for roads, utilities, and other built infrastructure, offering a level of reliability and risk management that green infrastructure alone may not be able to achieve. Determining the appropriate balance between green and gray infrastructure requires a clear understanding of site‑specific constraints, risks, and performance needs, an approach illustrated in the case studies that follow. Three Case Studies, Three Different Answers To explore how context drives design decisions, we recently examined three real‑world case studies, each involving active erosion, sediment transport, and downstream impacts, and each arriving at a different solution. 1. Flooding at the Lambertville Fire Department: When Gray Is the Right Choice In Lambertville, New Jersey, stormwater runoff from Music Mountain, a steep, wooded hillside, was causing repeated flooding at the Fire Department below. What appeared at first to be a small drainage issue turned out to be a much larger challenge. During heavy rain events, uncontrolled runoff carved deep erosion gullies downslope, destabilizing trees and transporting sediment directly into city infrastructure. While green infrastructure options such as step pools were initially considered, feasibility limitations became evident. The steep slope, limited footprint, and extreme peak flows made a fully nature-based solution impractical and risky in this location. Instead, the selected design centered on gray infrastructure, including a piped stormwater system aligned with the existing flow path to minimize disturbance, along with redesigned and expanded inlet and outlet controls to safely convey peak flows and better capture surface runoff. This approach stabilized the hillside, reduced downstream sediment transport, and eliminated flooding impacts at a critical municipal facility. Given the severe spatial constraints and elevated risk associated with the site, gray infrastructure represented the most responsible and effective solution. 2. Holcombe Park Restoration: A Hybrid Solution At Holcombe Park, ongoing erosion and a disconnected floodplain were impairing stream function and contributing sediment and debris to downstream infrastructure. Unlike the Lambertville Fire Department site, where steep slopes, limited space, and public safety risks necessitated a primarily gray solution, Holcombe Park offered greater physical flexibility and a different risk profile. The site included more available space for in‑channel and floodplain interventions, while the contributing drainage system extended more than 1,000 feet beneath roadways before releasing flows downstream, adding jurisdictional and infrastructure considerations to the design process. Given these conditions, the project team pursued a hybrid strategy that leveraged the strengths of both green and gray infrastructure. Green infrastructure measures, including floodplain reconnection, step pools, and naturalized channel features, were incorporated where space allowed to slow flows, reduce erosive forces, and restore ecological function. At the same time, existing gray infrastructure continued to convey stormwater through developed areas where open‑channel solutions were infeasible. By allowing floodwaters to spread out and attenuate within the park, the project reduces peak velocities and limits the transport of debris and sediment to downstream culverts and roadways. This case study illustrates how, when site conditions permit, integrating green and gray infrastructure can address erosion and water quality concerns while protecting downstream assets and enhancing recreational space, achieving outcomes that neither approach could deliver on its own. 3. Pennsylvania Stream Restoration: When Natural Systems Provide the Best Answer The third case study shifts to a more open, rural setting on a residential and agricultural property in Pennsylvania, where channel incision and bank instability had become a growing safety and land‑use concern. Unlike the urban conditions present in the Lambertville Fire Department and Holcombe Park projects, this site offered sufficient space for stream and floodplain processes to function, making it well‑suited for a predominantly green infrastructure approach. Initially, the landowner attempted to address the erosion by installing a large‑diameter pipe to rapidly convey water through the affected area. While this strategy appeared to resolve the immediate problem on site, it ultimately transferred impacts downstream. Concentrated discharges from the pipe destabilized channel banks, accelerated erosion, and created new problems beyond the property boundary, while also violating local waterway regulations. This outcome illustrated how applying gray infrastructure to a system experiencing watershed‑scale hydrologic change can unintentionally amplify downstream risks. The final design focused on restoring natural stream function rather than accelerating conveyance. The project realigned the channel to an appropriate slope and sinuosity, reconnected the stream to its floodplain, incorporated step pools and stabilization features to dissipate energy, and added riparian plantings to strengthen bank stability and ecological resilience. Limited sections of pipe were retained only where necessary to accommodate crossings, ensuring compatibility with existing land uses without compromising system function. With adequate space, funding, and regulatory drivers in place, natural green infrastructure proved to be the most effective and resilient solution for this site. By treating water as a resource rather than a waste product, the project reduced erosion and sediment transport, improved water quality, and restored stream and floodplain processes that benefit both the landscape and downstream communities. This case study also demonstrates that successful stormwater and erosion control requires solutions that respond to both local conditions and the larger watershed system. Key Takeaways: Context Is Everything Across all three projects, the lesson is clear: green or gray decisions must be driven by site context, not preference alone. Surrounding land use, physical constraints, risk tolerance, regulatory requirements, and stakeholder priorities all shape what “success” looks like. Improperly sized or poorly applied infrastructure, whether it be green or gray, will fail. Effective stormwater management requires looking beyond the immediate problem and designing solutions that reflect the realities of the entire watershed system. A Longstanding Partnership with Lambertville Princeton Hydro’s participation alongside Mayor Andrew Nowick in leading the educational session at the 2026 NJ Watershed Conference reflects a long‑standing partnership with the City of Lambertville and the City’s active role in applying context‑driven stormwater solutions in a constrained, developed watershed. Our team has supported Lambertville’s stormwater management initiatives for many years, working collaboratively with City leadership to design projects that mitigate flooding while enhancing the natural environment. In September 2024, New Jersey Department of Environmental Protection Commissioner Shawn M. LaTourette presented the City of Lambertville with the NJDEP “Our Water’s Worth It” award. The award ceremony, held at a stormwater infrastructure improvement project site behind the Lambertville Fire Department, recognized the City’s commitment to improving stormwater management, addressing flooding, protecting local waterbodies, increasing storm resilience, and mitigating the impacts of climate change. Click here to learn more. [post_title] => Green or Gray? Stormwater Solutions in Constrained Watersheds [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => green-or-gray-stormwater-solutions-in-constrained-watersheds [to_ping] => [pinged] => [post_modified] => 2026-04-06 19:40:48 [post_modified_gmt] => 2026-04-06 19:40:48 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=19515 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => WP_Post Object ( [ID] => 18641 [post_author] => 1 [post_date] => 2025-12-08 13:22:27 [post_date_gmt] => 2025-12-08 13:22:27 [post_content] => The Lower Darby Creek Area encompasses a unique blend of residential neighborhoods, commercial zones, and critical regional infrastructure, including the Philadelphia International Airport, Interstate 95, and portions of the John Heinz National Wildlife Refuge. Despite its urban setting, the area supports diverse wetlands, waterways, and wildlife habitats that play an essential role in regional flood protection, resiliency, and ecological connectivity. Flooding and habitat loss have long challenged the Lower Darby Creek Area, particularly in the communities of Eastwick in southwest Philadelphia and Tinicum Township of Delaware County, PA. Residents in these neighborhoods experience extreme flooding during storm and high tide events, and community groups have been leading local efforts to enhance resilience and reduce flood risk. The increasing effects of climate change, such as more intense storms, sea level rise, and frequent tidal flooding, are compounding challenges. To help address these challenges, The Nature Conservancy in Pennsylvania (TNC) and the John Heinz National Wildlife Refuge have commissioned Princeton Hydro to lead a two-year Urban Flood and Habitat Resilience Feasibility Study for the Lower Darby Creek Area. The study aims to identify and evaluate nature-based solutions that would help to convey, store, and infiltrate water to alleviate flooding, improve habitat for local wildlife species, and enhance community resilience. For this feasibility study, Princeton Hydro is combining field data collection, hydrologic and hydraulic modeling, and alternatives analysis to determine the most effective nature-based solutions that benefit both nature and people. These may include wetland creation or enhancement, stream and floodplain reconnection, and stormwater management retrofits designed to restore natural hydrologic function. Community engagement is a cornerstone of the Feasibility Study, ensuring that local voices help shape the region’s path toward long-term resilience. The project work began with a series of community meetings to learn from residents about the impacts of flooding and the changes they want to see in their neighborhoods. The outcome of this project will be a list of 6-10 nature-based solutions that have been prioritized by community members and that have been analyzed for feasibility and potential for flood reduction and ecological benefit. This information will be presented in a Project Roadmap for the co-developed pathway to achieve community and ecological resilience through project implementation. This guidance will empower partners and communities to secure funding, implement pilot projects, and advance long-term resilience goals. Once the study is complete, Princeton Hydro will create an interactive ArcGIS StoryMap webpage that will allow users to take a deeper dive into the study's findings and interact with the data. Users will be able to visualize flood scenarios and potential restoration opportunities and learn more about specific project activities and the proposed solutions. Community Engagement in Action: Eastwick Community Day Earlier this year, project partners joined residents for Eastwick Community Day, a vibrant event celebrating neighborhood connections, local leadership, and climate resilience. Hosted by the City of Philadelphia’s Office of Sustainability, the event was supported by representatives from The Nature Conservancy in Pennsylvania, John Heinz National Wildlife Refuge, and Princeton Hydro, including Director of Restoration & Resilience Christiana Pollack, CERP, CFM, GISP and Director of Aquatics Mike Hartshorne. The gathering offered residents an opportunity to meet the organizations involved in the flood study, learn about available climate resilience resources, and share their own experiences and priorities. Alongside informational displays and project updates, attendees enjoyed a picnic lunch, family activities, and hands-on learning about nature-based solutions. It was a day that captured the spirit of collaboration driving this initiative. Check out some highlights from the day, captured by Kim Hachadoorian, Stream Stewards Project Manager for The Nature Conservancy: [gallery columns="2" link="none" ids="17637,17638,17631,17635"] Building on the Eastwick Flood Resilience Study The Lower Darby Creek initiative builds on Princeton Hydro’s earlier Eastwick Flood Resilience Study, expanding from a neighborhood-focused analysis to a watershed-scale approach. In 2016, in partnership with the University of Pennsylvania, the John Heinz National Wildlife Refuge, Keystone Conservation Trust, Audubon Pennsylvania, and the William Penn Foundation, Princeton Hydro conducted an analysis of Eastwick, the flood impacts created by the Lower Darby Creek, and the viability of several potential flood mitigation strategies. The study sought to answer questions commonly asked by community members related to flooding conditions, with the main question being: What impact does the landfill have on area flooding? Princeton Hydro developed a 2-D hydrologic and hydraulic model to understand how varying restoration techniques, including removal of the Clearview Landfill, expansion of the existing tidal freshwater wetland, removal of bridge infrastructure, and rerouting storm flows, would alter flooding in the Eastwick neighborhood. Findings from that study provided key data and analytical frameworks that now inform the Lower Darby Creek Area Feasibility Study. Expanding beyond the boundaries of Eastwick, the comprehensive Lower Darby Creek Area study takes a watershed-scale view, exploring how interconnected systems, including upstream hydrology, tidal influences, and habitat networks, can be managed holistically. [caption id="attachment_7896" align="aligncenter" width="751"] Princeton Hydro developed a 2-dimensional hydrologic and hydraulic model to understand how varying restoration techniques would alter flooding in the Eastwick neighborhood.[/caption] Partnerships for a Resilient Future Resilience is not achieved in isolation; it thrives through collaboration. The success of the Lower Darby Creek Area Feasibility Study and related restoration projects depends on a network of partners committed to shared goals. By aligning expertise, resources, and local knowledge, these partnerships create a foundation for long-term climate adaptation and ecological health. To learn more about the Nature Conservancy in Pennsylvania, click here. To learn more about the City of Philadelphia Office of Sustainability Flood Resilience Strategy for Eastwick, go here. And, click here to learn more about the John Heinz National Wildlife Refuge in Tinicum. Princeton Hydro is also collaborating with the Refuge to restore the Refuge’s Turkey Foot area. Working with Enviroscapes and Merestone Consultants, our team designed and implemented habitat enhancement and hydrologic restoration projects to improve water quality, restore native wetland vegetation, and expand habitat for fish and wildlife. If you’re interested in learning more about this project, check out our blog: Ecological Restoration in John Heinz National Wildlife Refuge. [post_title] => Building Resilience: Exploring Nature-Based Solutions in Lower Darby Creek [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => building-resilience-exploring-nature-based-solutions-in-lower-darby-creek [to_ping] => [pinged] => [post_modified] => 2025-12-10 15:03:38 [post_modified_gmt] => 2025-12-10 15:03:38 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18641 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [2] => WP_Post Object ( [ID] => 17931 [post_author] => 1 [post_date] => 2025-07-22 21:39:22 [post_date_gmt] => 2025-07-22 21:39:22 [post_content] => The Steven R. Rothman Overlook and Preserve, a new five-acre public open space in the heart of the Meadowlands, is now open to the public. Situated within the 587-acre Richard P. Kane Natural Area, the preserve offers an ADA-accessible gateway into one of New Jersey's most ecologically significant landscapes. Visitors can enjoy sweeping views of the Meadowlands and the New York City skyline while immersing themselves in a protected wetland ecosystem that lies along the Atlantic Flyway, a vital route for migratory birds. Owned by the Meadowlands Conservation Trust (MCT) and managed by the New Jersey Sports and Exposition Authority (NJSEA), the site supports a wide range of native and rare wildlife and plant species. On July 10, local and state leaders gathered to officially dedicate the new preserve and celebrate the extraordinary efforts of former U.S. Congressman Steven R. Rothman, whose leadership was instrumental in preserving the region's critical wetlands. The ceremony brought together Governor Phil Murphy, Congressman Rothman, officials from Bergen County, NY/NJ Baykeeper, Hackensack Riverkeeper, MCT, NJSEA, project partners and community members. The event featured remarks, reflections and a ceremonial tree planting. [gallery link="none" ids="17871,17868,17870"] Addressing Congressman Rothman, "We are so proud and happy that this is named after you. You stood up when a lot of others would not. You took a bold stance. You believed in preserving the Meadowlands. We thank you and congratulate you," expressed Greg Remaud, CEO of NY/NJ Baykeeper, at the event. A century ago, the New Jersey Meadowlands spanned over 21,000 acres of open space. Today, only 8,400 acres remain largely undeveloped. Speakers at the event reflected on the decades-long fight to protect this land, which was once targeted for commercial development, including plans for what would become the American Dream Mall. That 15-year preservation effort ultimately secured the future of this critical habitat. Governor Murphy emphasized Rothman's role in that success: "Congressman Steven R. Rothman played an oversized role in protecting this incredible expanse of treasured, public open space, and he has been an ardent supporter of the Meadowlands in Congress and as a private citizen. I commend Congressman Rothman’s steadfast determination and that of the Meadowlands Conservation Trust in saving our natural resources." Congressman Rothman also addressed the crowd, sharing his hope for the future of the site: "This overlook and preserve will now help assure that future generations of New Jerseyans and others will learn about this area's rich natural life and a history of how this space was saved from development.” About Congressman Rothman Congressman Rothman represented New Jersey’s 9th Congressional District from 1997 to 2013, serving in the U.S. House of Representatives for 16 years. For nearly a decade, Congressman Rothman played a pivotal role in the fight to protect what remained of the Hackensack Meadowlands' undeveloped wetlands. At a time when large-scale development threatened the ecological integrity of the region, he brought national attention to the cause, becoming the first U.S. congressional candidate, and later Congressman, to publicly oppose projects like the proposed American Dream Mall. His advocacy helped relocate the development to a more suitable location and catalyzed a broader conservation movement. Recognizing the ecological significance of the Meadowlands, Congressman Rothman secured $10 million in federal funding, along with additional state and local contributions, to support land acquisition, environmental remediation, and permanent protection of the remaining open space. He brought together key stakeholders, took a firm public stance on what must be preserved, and was instrumental in the formal rezoning of 8,400 acres as undevelopable. Widely acknowledged as the catalyst behind one of New Jersey’s most consequential land preservation efforts, Rothman received multiple regional and national honors for his leadership. The dedication of this new preserve in his name serves as a lasting tribute to his legacy. Designing a Sustainable, Inclusive Public Space The project was a design-build collaboration led by SumCo Eco-Contracting, with design services provided by Princeton Hydro, including environmental, civil, and geotechnical engineering; landscape architecture; and construction oversight. The team approached the project with a deep sense of care and responsibility. “It’s been a privilege to support the vision for this park,” said Cory Speroff, PLA, ASLA, CBLP, Landscape Architect and Project Manager at Princeton Hydro. “From the beginning, we approached the design with a sense of responsibility and sensitivity, knowing how many people have worked tirelessly over the years to protect and preserve the surrounding wetlands. Our goal was to create a space that honors that legacy — a place where people can come to connect with the Meadowlands.” The newly constructed preserve includes a range of low-impact park features that balance ecological protection with meaningful public access:
In developed watersheds, stormwater behavior is fundamentally altered by impervious surfaces and aging infrastructure, which can result in erosion, localized flooding, and nutrient pollution in surrounding waterways. These challenges rarely have simple or universal solutions, particularly in communities where natural systems, critical infrastructure, and public safety intersect within constrained landscapes.
How practitioners navigate these challenges and decide when to rely on green, gray, or hybrid stormwater solutions was the focus of a recent educational session at The Watershed Institute’s 9th Annual New Jersey Watershed Conference. The session, led by Princeton Hydro Water Resources Engineer Sean Walsh, PE and Landscape Architect Jamie Feinstein, RLA, alongside the Mayor of Lambertville (NJ) Andrew Nowick, explored how context‑driven design informs effective stormwater and erosion control strategies in developed environments.
Drawing from three real‑world case studies, the presenters examined how surrounding land use, physical constraints, risk tolerance, and stakeholder priorities shape decision‑making and why the most effective stormwater solutions are rarely one‑size‑fits‑all. This blog summarizes key lessons from that presentation, highlighting how site‑specific conditions ultimately determine whether green infrastructure, gray infrastructure, or a hybrid approach is the most appropriate tool for managing erosion, sediment, and flooding in settings shaped by competing land‑use and infrastructure demands.
Green infrastructure is designed to manage stormwater by mimicking natural hydrologic and geomorphic processes that are often altered or suppressed by development. Practices such as floodplain reconnection, step pools, riparian buffers, naturalized detention basins, and restored stream channels slow runoff, promote infiltration, and moderate sediment transport, while also improving water quality. When implemented at appropriate scales, these approaches can increase green space within built and urban environments, enhance habitat and biodiversity, and enrich the surrounding landscape by integrating stormwater management with ecological and recreational functions. However, the feasibility and performance of green infrastructure are highly dependent on site‑specific conditions, including available space, slope, and flow regimes, which are frequently constrained in urban environments.
Gray infrastructure, by contrast, is designed to prioritize conveyance, control, and predictability. Systems such as pipes, culverts, and engineered structures are well‑suited to managing high‑capacity flow rates, centralizing stormwater runoff, and conveying water safely through constrained environments. These approaches typically require smaller physical footprints than nature‑based alternatives and often involve lower long‑term maintenance demands. In developed settings, gray infrastructure can also provide critical structural support for roads, utilities, and other built infrastructure, offering a level of reliability and risk management that green infrastructure alone may not be able to achieve.
Determining the appropriate balance between green and gray infrastructure requires a clear understanding of site‑specific constraints, risks, and performance needs, an approach illustrated in the case studies that follow.
To explore how context drives design decisions, we recently examined three real‑world case studies, each involving active erosion, sediment transport, and downstream impacts, and each arriving at a different solution.
In Lambertville, New Jersey, stormwater runoff from Music Mountain, a steep, wooded hillside, was causing repeated flooding at the Fire Department below. What appeared at first to be a small drainage issue turned out to be a much larger challenge. During heavy rain events, uncontrolled runoff carved deep erosion gullies downslope, destabilizing trees and transporting sediment directly into city infrastructure. While green infrastructure options such as step pools were initially considered, feasibility limitations became evident. The steep slope, limited footprint, and extreme peak flows made a fully nature-based solution impractical and risky in this location.
Instead, the selected design centered on gray infrastructure, including a piped stormwater system aligned with the existing flow path to minimize disturbance, along with redesigned and expanded inlet and outlet controls to safely convey peak flows and better capture surface runoff. This approach stabilized the hillside, reduced downstream sediment transport, and eliminated flooding impacts at a critical municipal facility. Given the severe spatial constraints and elevated risk associated with the site, gray infrastructure represented the most responsible and effective solution.
At Holcombe Park, ongoing erosion and a disconnected floodplain were impairing stream function and contributing sediment and debris to downstream infrastructure. Unlike the Lambertville Fire Department site, where steep slopes, limited space, and public safety risks necessitated a primarily gray solution, Holcombe Park offered greater physical flexibility and a different risk profile. The site included more available space for in‑channel and floodplain interventions, while the contributing drainage system extended more than 1,000 feet beneath roadways before releasing flows downstream, adding jurisdictional and infrastructure considerations to the design process.
Given these conditions, the project team pursued a hybrid strategy that leveraged the strengths of both green and gray infrastructure. Green infrastructure measures, including floodplain reconnection, step pools, and naturalized channel features, were incorporated where space allowed to slow flows, reduce erosive forces, and restore ecological function. At the same time, existing gray infrastructure continued to convey stormwater through developed areas where open‑channel solutions were infeasible. By allowing floodwaters to spread out and attenuate within the park, the project reduces peak velocities and limits the transport of debris and sediment to downstream culverts and roadways. This case study illustrates how, when site conditions permit, integrating green and gray infrastructure can address erosion and water quality concerns while protecting downstream assets and enhancing recreational space, achieving outcomes that neither approach could deliver on its own.
The third case study shifts to a more open, rural setting on a residential and agricultural property in Pennsylvania, where channel incision and bank instability had become a growing safety and land‑use concern. Unlike the urban conditions present in the Lambertville Fire Department and Holcombe Park projects, this site offered sufficient space for stream and floodplain processes to function, making it well‑suited for a predominantly green infrastructure approach.
Initially, the landowner attempted to address the erosion by installing a large‑diameter pipe to rapidly convey water through the affected area. While this strategy appeared to resolve the immediate problem on site, it ultimately transferred impacts downstream. Concentrated discharges from the pipe destabilized channel banks, accelerated erosion, and created new problems beyond the property boundary, while also violating local waterway regulations. This outcome illustrated how applying gray infrastructure to a system experiencing watershed‑scale hydrologic change can unintentionally amplify downstream risks.
The final design focused on restoring natural stream function rather than accelerating conveyance. The project realigned the channel to an appropriate slope and sinuosity, reconnected the stream to its floodplain, incorporated step pools and stabilization features to dissipate energy, and added riparian plantings to strengthen bank stability and ecological resilience. Limited sections of pipe were retained only where necessary to accommodate crossings, ensuring compatibility with existing land uses without compromising system function.
With adequate space, funding, and regulatory drivers in place, natural green infrastructure proved to be the most effective and resilient solution for this site. By treating water as a resource rather than a waste product, the project reduced erosion and sediment transport, improved water quality, and restored stream and floodplain processes that benefit both the landscape and downstream communities. This case study also demonstrates that successful stormwater and erosion control requires solutions that respond to both local conditions and the larger watershed system.
Across all three projects, the lesson is clear: green or gray decisions must be driven by site context, not preference alone. Surrounding land use, physical constraints, risk tolerance, regulatory requirements, and stakeholder priorities all shape what “success” looks like.
Improperly sized or poorly applied infrastructure, whether it be green or gray, will fail. Effective stormwater management requires looking beyond the immediate problem and designing solutions that reflect the realities of the entire watershed system.
Princeton Hydro’s participation alongside Mayor Andrew Nowick in leading the educational session at the 2026 NJ Watershed Conference reflects a long‑standing partnership with the City of Lambertville and the City’s active role in applying context‑driven stormwater solutions in a constrained, developed watershed. Our team has supported Lambertville’s stormwater management initiatives for many years, working collaboratively with City leadership to design projects that mitigate flooding while enhancing the natural environment.
In September 2024, New Jersey Department of Environmental Protection Commissioner Shawn M. LaTourette presented the City of Lambertville with the NJDEP “Our Water’s Worth It” award. The award ceremony, held at a stormwater infrastructure improvement project site behind the Lambertville Fire Department, recognized the City’s commitment to improving stormwater management, addressing flooding, protecting local waterbodies, increasing storm resilience, and mitigating the impacts of climate change. Click here to learn more.
The Lower Darby Creek Area encompasses a unique blend of residential neighborhoods, commercial zones, and critical regional infrastructure, including the Philadelphia International Airport, Interstate 95, and portions of the John Heinz National Wildlife Refuge. Despite its urban setting, the area supports diverse wetlands, waterways, and wildlife habitats that play an essential role in regional flood protection, resiliency, and ecological connectivity.
Flooding and habitat loss have long challenged the Lower Darby Creek Area, particularly in the communities of Eastwick in southwest Philadelphia and Tinicum Township of Delaware County, PA. Residents in these neighborhoods experience extreme flooding during storm and high tide events, and community groups have been leading local efforts to enhance resilience and reduce flood risk. The increasing effects of climate change, such as more intense storms, sea level rise, and frequent tidal flooding, are compounding challenges.
To help address these challenges, The Nature Conservancy in Pennsylvania (TNC) and the John Heinz National Wildlife Refuge have commissioned Princeton Hydro to lead a two-year Urban Flood and Habitat Resilience Feasibility Study for the Lower Darby Creek Area. The study aims to identify and evaluate nature-based solutions that would help to convey, store, and infiltrate water to alleviate flooding, improve habitat for local wildlife species, and enhance community resilience.
Community engagement is a cornerstone of the Feasibility Study, ensuring that local voices help shape the region’s path toward long-term resilience. The project work began with a series of community meetings to learn from residents about the impacts of flooding and the changes they want to see in their neighborhoods. The outcome of this project will be a list of 6-10 nature-based solutions that have been prioritized by community members and that have been analyzed for feasibility and potential for flood reduction and ecological benefit. This information will be presented in a Project Roadmap for the co-developed pathway to achieve community and ecological resilience through project implementation. This guidance will empower partners and communities to secure funding, implement pilot projects, and advance long-term resilience goals.
Once the study is complete, Princeton Hydro will create an interactive ArcGIS StoryMap webpage that will allow users to take a deeper dive into the study's findings and interact with the data. Users will be able to visualize flood scenarios and potential restoration opportunities and learn more about specific project activities and the proposed solutions.
Earlier this year, project partners joined residents for Eastwick Community Day, a vibrant event celebrating neighborhood connections, local leadership, and climate resilience. Hosted by the City of Philadelphia’s Office of Sustainability, the event was supported by representatives from The Nature Conservancy in Pennsylvania, John Heinz National Wildlife Refuge, and Princeton Hydro, including Director of Restoration & Resilience Christiana Pollack, CERP, CFM, GISP and Director of Aquatics Mike Hartshorne.
The gathering offered residents an opportunity to meet the organizations involved in the flood study, learn about available climate resilience resources, and share their own experiences and priorities. Alongside informational displays and project updates, attendees enjoyed a picnic lunch, family activities, and hands-on learning about nature-based solutions. It was a day that captured the spirit of collaboration driving this initiative.
The Lower Darby Creek initiative builds on Princeton Hydro’s earlier Eastwick Flood Resilience Study, expanding from a neighborhood-focused analysis to a watershed-scale approach. In 2016, in partnership with the University of Pennsylvania, the John Heinz National Wildlife Refuge, Keystone Conservation Trust, Audubon Pennsylvania, and the William Penn Foundation, Princeton Hydro conducted an analysis of Eastwick, the flood impacts created by the Lower Darby Creek, and the viability of several potential flood mitigation strategies. The study sought to answer questions commonly asked by community members related to flooding conditions, with the main question being: What impact does the landfill have on area flooding? Princeton Hydro developed a 2-D hydrologic and hydraulic model to understand how varying restoration techniques, including removal of the Clearview Landfill, expansion of the existing tidal freshwater wetland, removal of bridge infrastructure, and rerouting storm flows, would alter flooding in the Eastwick neighborhood.
Findings from that study provided key data and analytical frameworks that now inform the Lower Darby Creek Area Feasibility Study. Expanding beyond the boundaries of Eastwick, the comprehensive Lower Darby Creek Area study takes a watershed-scale view, exploring how interconnected systems, including upstream hydrology, tidal influences, and habitat networks, can be managed holistically.
Resilience is not achieved in isolation; it thrives through collaboration. The success of the Lower Darby Creek Area Feasibility Study and related restoration projects depends on a network of partners committed to shared goals. By aligning expertise, resources, and local knowledge, these partnerships create a foundation for long-term climate adaptation and ecological health. To learn more about the Nature Conservancy in Pennsylvania, click here. To learn more about the City of Philadelphia Office of Sustainability Flood Resilience Strategy for Eastwick, go here. And, click here to learn more about the John Heinz National Wildlife Refuge in Tinicum.
Princeton Hydro is also collaborating with the Refuge to restore the Refuge’s Turkey Foot area. Working with Enviroscapes and Merestone Consultants, our team designed and implemented habitat enhancement and hydrologic restoration projects to improve water quality, restore native wetland vegetation, and expand habitat for fish and wildlife. If you’re interested in learning more about this project, check out our blog: Ecological Restoration in John Heinz National Wildlife Refuge.
The Steven R. Rothman Overlook and Preserve, a new five-acre public open space in the heart of the Meadowlands, is now open to the public.
Situated within the 587-acre Richard P. Kane Natural Area, the preserve offers an ADA-accessible gateway into one of New Jersey's most ecologically significant landscapes. Visitors can enjoy sweeping views of the Meadowlands and the New York City skyline while immersing themselves in a protected wetland ecosystem that lies along the Atlantic Flyway, a vital route for migratory birds. Owned by the Meadowlands Conservation Trust (MCT) and managed by the New Jersey Sports and Exposition Authority (NJSEA), the site supports a wide range of native and rare wildlife and plant species.
On July 10, local and state leaders gathered to officially dedicate the new preserve and celebrate the extraordinary efforts of former U.S. Congressman Steven R. Rothman, whose leadership was instrumental in preserving the region's critical wetlands. The ceremony brought together Governor Phil Murphy, Congressman Rothman, officials from Bergen County, NY/NJ Baykeeper, Hackensack Riverkeeper, MCT, NJSEA, project partners and community members. The event featured remarks, reflections and a ceremonial tree planting.
Addressing Congressman Rothman, "We are so proud and happy that this is named after you. You stood up when a lot of others would not. You took a bold stance. You believed in preserving the Meadowlands. We thank you and congratulate you," expressed Greg Remaud, CEO of NY/NJ Baykeeper, at the event.
A century ago, the New Jersey Meadowlands spanned over 21,000 acres of open space. Today, only 8,400 acres remain largely undeveloped. Speakers at the event reflected on the decades-long fight to protect this land, which was once targeted for commercial development, including plans for what would become the American Dream Mall. That 15-year preservation effort ultimately secured the future of this critical habitat.
Governor Murphy emphasized Rothman's role in that success: "Congressman Steven R. Rothman played an oversized role in protecting this incredible expanse of treasured, public open space, and he has been an ardent supporter of the Meadowlands in Congress and as a private citizen. I commend Congressman Rothman’s steadfast determination and that of the Meadowlands Conservation Trust in saving our natural resources."
Congressman Rothman also addressed the crowd, sharing his hope for the future of the site: "This overlook and preserve will now help assure that future generations of New Jerseyans and others will learn about this area's rich natural life and a history of how this space was saved from development.”
Congressman Rothman represented New Jersey’s 9th Congressional District from 1997 to 2013, serving in the U.S. House of Representatives for 16 years.
For nearly a decade, Congressman Rothman played a pivotal role in the fight to protect what remained of the Hackensack Meadowlands' undeveloped wetlands. At a time when large-scale development threatened the ecological integrity of the region, he brought national attention to the cause, becoming the first U.S. congressional candidate, and later Congressman, to publicly oppose projects like the proposed American Dream Mall. His advocacy helped relocate the development to a more suitable location and catalyzed a broader conservation movement.
Recognizing the ecological significance of the Meadowlands, Congressman Rothman secured $10 million in federal funding, along with additional state and local contributions, to support land acquisition, environmental remediation, and permanent protection of the remaining open space. He brought together key stakeholders, took a firm public stance on what must be preserved, and was instrumental in the formal rezoning of 8,400 acres as undevelopable. Widely acknowledged as the catalyst behind one of New Jersey’s most consequential land preservation efforts, Rothman received multiple regional and national honors for his leadership. The dedication of this new preserve in his name serves as a lasting tribute to his legacy.
The project was a design-build collaboration led by SumCo Eco-Contracting, with design services provided by Princeton Hydro, including environmental, civil, and geotechnical engineering; landscape architecture; and construction oversight.
The team approached the project with a deep sense of care and responsibility. “It’s been a privilege to support the vision for this park,” said Cory Speroff, PLA, ASLA, CBLP, Landscape Architect and Project Manager at Princeton Hydro. “From the beginning, we approached the design with a sense of responsibility and sensitivity, knowing how many people have worked tirelessly over the years to protect and preserve the surrounding wetlands. Our goal was to create a space that honors that legacy — a place where people can come to connect with the Meadowlands.”
The newly constructed preserve includes a range of low-impact park features that balance ecological protection with meaningful public access:
All elements were designed to be fully ADA-compliant, ensuring inclusive access for visitors of all abilities. The trail and parking surfaces were constructed using a geocellular confinement system, which promotes stormwater infiltration and supports long-term structural integrity. A timber guardrail was added along the drive and parking area to enhance safety and define boundaries.
In consideration of the site’s role as critical habitat, particularly for nocturnal and migratory species, artificial lighting was not included in the design.
Ecological restoration was a central focus of the project. The team planted 40 native trees and shrubs, installed a pollinator garden, and seeded the site with native, drought-tolerant grasses to improve habitat value and resilience. These nature-based enhancements not only support biodiversity but also help filter stormwater, stabilize soils, and prepare the landscape for a changing climate.
The preserve, located at the end of Jomike Court in Carlstadt, NJ, is now open daily from dawn to dusk. Visitors are encouraged to explore the trail, take in the sweeping New York City skyline views from the overlook, and appreciate the beauty and ecological richness of the Meadowlands.
Looking for more examples of how design and ecology can come together to benefit both people and nature? Check out our work at South Cape May Meadows Preserve in partnership with The Nature Conservancy in New Jersey. This beloved 200-acre coastal habitat, an international hotspot for birdwatching, draws more than 90,000 visitors annually. Princeton Hydro is helping to restore the preserve’s ecological integrity while improving public access, including recent efforts to remove invasive Phragmites and promote the return of native vegetation. Read more about the project here.
Invasive species can quickly establish themselves in habitats ranging from freshwater wetlands and riparian corridors to stormwater basins and tidal marshes, disrupting ecological balance and biodiversity, altering hydrology, and displacing native species.
Addressing these impacts requires a thoughtful, site-specific approach. Our team at Princeton Hydro works to design and implement targeted strategies that promote long-term ecological function. These integrated efforts aid in native habitat recovery, enhance water quality, and support compliance with regulatory frameworks.
Let’s take a closer look at how invasive species disrupt our ecosystems, why managing them is so important, and the cutting-edge tools and innovative techniques helping to eradicate invasives and restore balance to delicate ecosystems.
Invasive species are organisms introduced outside their native range that proliferate in new environments, often to the detriment of local ecosystems and biodiversity. Although some introductions happen naturally, most are caused by human activity—through commercial shipping and transport, travel and outdoor recreation, or sometimes deliberate introduction. Once established, invasive species often outcompete native species by growing more aggressively, reproducing more rapidly, and exploiting resources more efficiently. These advantages are amplified by the absence of natural predators and environmental controls that would normally regulate their populations.
This can lead to a cascade of ecological consequences:
Take common reed (Phragmites australis), for example. This fast-growing plant has overtaken many wetlands, meadows, and shorelines, forming dense stands that outcompete native vegetation. These monocultures reduce food sources that native species rely on and block the movement of wildlife between critical habitats. According to the National Invasive Species Information Center (NISIC), Phragmites was most likely introduced during the 1800s in ballast material used on ships. It was initially established along the Atlantic coast and quickly spread across the continent.
Another example of an aggressive invasive species is Eurasian watermilfoil (Myriophyllum spicatum), a submerged perennial aquatic plant that grows in lakes and ponds. Native to Europe, Asia, and North Africa, it was discovered in the eastern U.S. in the early 1900s, likely introduced and spread through the movement of watercraft. It establishes itself very quickly, grows rapidly, and spreads easily, forming dense mats at the water’s surface.
Left unmanaged, aggressive invasives like Phragmites and Eurasian watermilfoil can severely impact the stability of critical environmental systems. Effective control strategies help restore balance, preserve biodiversity, and safeguard the services ecosystems provide to humans and wildlife alike.
At Princeton Hydro, we use a multifaceted approach to invasive species control, employing mechanical, herbicidal, and biological strategies depending on the specific site conditions and project goals. One of our most effective tools is the Marsh Master® 2MX-KC-FH, a fully amphibious machine built to operate with minimal environmental disruption.
Equipped with hydraulic rotary cutting blades, a rear mounted roller/chopper attachment, and a front vegetation plow, the Marsh Master® cuts through dense vegetation like Phragmites, then chops and rolls the stalks, effectively preparing the soil for native seed germination or plug installation, making it ideal for nature preserves, canal banks, and restoration sites. Its light footprint (less than one pound per square inch) means it can traverse sensitive areas without damaging the soil or root layer.
Take a look at the Marsh Master® in the field, tackling Phragmites in tough terrain:
When paired with herbicide treatments and long-term monitoring, this approach has proven very effective in eradicating invasives, restoring wetland biodiversity, improving water quality, and creating wildlife habitat. Each site is carefully analyzed and, when required for optimal non-native plant management, a site-specific USEPA and state-registered herbicide is chosen to control the target plants while preserving the desirable, native vegetation currently populating the site. Application techniques, which are also specific to each site, include machine broadcast spraying, backpack foliar spraying, hand-wiping, basal applications, herbicide injection lances, along with various other techniques.
In partnership with GreenVest and the U.S. Army Corps of Engineers Baltimore District, Princeton Hydro contributed to a tidal marsh restoration project along the Patapsco River in Baltimore, Maryland. This initiative is part of the broader “Reimagine Middle Branch” plan, a community-driven revitalization effort to restore natural habitat and improve public access along 11 miles of Patapsco River shoreline.
At the project site near Reed Bird Island, roughly five acres of marsh had been overtaken by dense stands of Phragmites. The goal was to restore hydrologic connections to the Patapsco River and convert the monoculture into a thriving mosaic of native marsh vegetation. Our team used the Marsh Master® to mow and manage the Phragmites, followed by mechanical grading and sediment redistribution to create high and low marsh zones. The restoration plan included planting 5+ acres with a combination of native species and incorporating habitat features like woody debris and unplanted cobblestone patches to facilitate fish passage.
This project demonstrates how targeted invasive species control can support large-scale ecosystem restoration, community-led initiatives, and watershed-wide environmental goals.
Princeton Hydro has worked alongside New Jersey’s Mercer County Park Commission for over a decade to restore and protect some of the region’s most ecologically valuable landscapes. From comprehensive planning to boots-on-the-ground restoration, our efforts have focused on mitigating the spread of invasive species and promoting long-term ecological resilience.
John A. Roebling Memorial Park, part of the Abbott Marshlands, an ecologically rich freshwater tidal ecosystem that contains valuable habitat for many rare species, experienced a significant amount of loss and degradation, partially due to the introduction of Phragmites. In areas where Phragmites had overtaken native wetland communities, our team developed and executed an invasive species management plan tailored to the park’s unique hydrology and habitat types. Seasonal mowing in the winter and early spring with the Marsh Master® and targeted herbicide applications helped suppress invasive growth and enabled the rebound of native species, including Wild rice (Zizania aquatica), a culturally and ecologically significant plant.
Building on that success, we contributed to the development and implementation of the Master Plan for the Miry Run Dam Site 21, a comprehensive roadmap for ecological restoration and public access. We are advancing that vision through mitigating invasive species (primarily Phragmites), leading lake dredging, and executing a variety of habitat uplift efforts. Click here to learn more about this award-winning restoration initiative.
In 2024, Mercer County retained Princeton Hydro under an on-call contract for invasive species management across its park system, enabling our team to respond rapidly to emerging threats and support the county’s ongoing commitment to long-term ecosystem health.
At the Lower Raritan Mitigation Site in central New Jersey, Princeton Hydro has led a multi-year invasive species control effort as part of a larger wetland and stream restoration initiative. Dominated by reed canary grass (Phalaris arundinacea) and Phragmites, the site had lost most (if not all) of its native biodiversity and ecological function.
Our team used a phased approach—mechanical mowing, herbicide treatment, and active planting of native species—to gradually suppress invasives and restore a healthy plant community. Monitoring data over several growing seasons has shown a significant decrease in invasive cover and a measurable increase in native diversity. Ongoing eradication of aggressive species and the promotion of native plant diversity are steadily guiding the site toward a resilient, self-sustaining ecosystem.
Owned and managed by The Nature Conservancy in New Jersey, the South Cape May Meadows Preserve is a 200-acre freshwater wetland and coastal habitat in southern New Jersey that serves as a critical refuge for migratory birds and other native wildlife. The preserve attracts over 90,000 visitors each year and is internationally recognized as a prime birdwatching destination.
Princeton Hydro is collaborating with The Nature Conservancy on a multi-faceted effort to both improve public access and restore the site’s ecological integrity. In 2023 and 2024, our team initiated the mechanical removal of dense stands of Phragmites using the Marsh Master® to suppress monocultures and promote native plant regeneration. Future phases may include targeted herbicide treatments and additional mechanical work.
In addition to the invasive species management component, this project collaboration has led to the construction of 2,675 feet of new elevated boardwalks, a 480-square-foot viewing platform, and enhancements to existing trails. Designing and installing these features across sensitive wetland terrain required a thoughtful, low-impact approach. The result is a more welcoming, species-rich, and resilient landscape that invites people into nature while actively protecting it.
Invasive vegetation doesn’t just affect wild landscapes, it also poses challenges for stormwater infrastructure. Many municipalities struggle with invasives overtaking stormwater basins, reducing their capacity and function, which can lead to violations of Municipal Separate Storm Sewer System (MS4) permits and municipality stormwater management regulatory requirements.
Princeton Hydro designs and implements comprehensive stormwater basin maintenance programs that include invasive species management. Removing Phragmites, broadleaf cattail (Typha latifolia), and other aggressive species from stormwater infrastructure helps to restore hydrologic flow and ensures the basins perform as designed. These maintenance programs also help maintain MS4 compliance, protect downstream water quality, and reduce flooding risks—while enhancing habitat value where possible.
The fight against invasive and aggressive non-native species is ongoing, and success requires a combination of science, strategy, and stewardship. Each effort implemented and every acre reclaimed is a step toward protecting the ecosystems we all depend on.
Nestled within the New Jersey townships of Hamilton, Robbinsville, and West Windsor lies Miry Run Dam Site 21—an expansive 279-acre parcel with a rich history dating back to its acquisition by Mercer County in the late 1970s. Originally earmarked for flood mitigation and recreation, this hidden gem is on the cusp of a remarkable transformation, poised to unveil its true potential as a thriving public park.
Central to the revitalization efforts is a comprehensive Master Plan, meticulously crafted by Mercer County Park Commission in partnership with Simone Collins Landscape Architecture and Princeton Hydro. This visionary roadmap encompasses a spectrum of engineering and ecological uplift initiatives, including:
The Master Plan serves as a long-term vision for improvements to the property and will be implemented over multiple phases. In 2021, it was recognized with the Landscape Architectural Chapter Award from the New Jersey Chapter American Society of Landscape Architects, which underscores its innovative and impactful approach to landscape design.
Now, Dam Site 21’s revitalization has begun with a crucial endeavor: the dredging of its 50-acre lake. This process, spearheaded by Mercer County Park Commission in collaboration with Princeton Hydro, aims to rejuvenate the water body by removing accumulated debris, sediment, and invasive vegetation—a vital step towards restoring its ecological balance. Beyond the aesthetic and ecological improvements, dredging enhances accessibility for recreational activities that provide an opportunity to create a deeper connection between the park’s visitors and its beautiful natural landscape.
Based on the bathymetric assessment, which the Princeton Hydro team completed as part of the Master Plan, the dredging efforts are focused on three primary areas: Area 1 is located in the main body of the lake just downstream of Line Road and will generate approximately 34,000 cubic yards of dredged material; Area 2, which has approximately 4,900 cubic yards of accumulated sediment is located in the northeast cove, just north of Area 1; and Area 3, the northwestern cove, entails the removal of approximately 7,300 cubic yards of accumulated sediment.
Before the dredging work could begin, the Princeton Hydro team was responsible for providing a sediment sampling plan, sample collection and laboratory analysis, engineering design plan, preparation and submission of all NJDEP regulatory permitting materials, preparation of the technical specifications, and bid administration. Currently, our team is providing construction administration and oversight for the project.
The journey towards Dam Site 21's revival has been marked by meticulous planning, design, and community engagement spanning several years. With the commencement of dredging operations, the project's vision is gradually materializing—a testament to the dedication of all stakeholders involved. As the first phase unfolds, anticipation mounts for the realization of a vibrant, inclusive public space that honors both nature and community.
As Dam Site 21 undergoes its metamorphosis, it symbolizes not just a physical restoration, but a renewal of collective vision and commitment. Ultimately, Dam Site 21 isn't just a park—it's a testament to the enduring legacy of conservation, community, and the transformative power of restoration.
The significance of Dam Site 21's transformation extends far beyond its recreational appeal. It embodies a commitment to environmental stewardship, with measures aimed at bolstering flood resilience, improving water quality, and nurturing diverse wildlife habitats. By blending conservation with recreation, the project strikes an important balance between creating access for community members to enjoy the space and ecological preservation that puts native plants, critical habitat, and wildlife at the forefront.
To learn more about the restoration initiative and view the Final Master Plan, visit the Mercer County Park Commission’s website. Click here to learn about another one of Princeton Hydro’s recent restoration efforts. And, stay tuned here for more Mercer County Park Commission project updates!
400 native plants were installed along the western shoreline of Memorial Pond in Mount Arlington, New Jersey. The planting was completed in one day by a team of 20+ volunteers, staff members from Mt. Arlington Department of Public Works (DPW), Lake Hopatcong Foundation, Lake Hopatcong Commission, Princeton Hydro, and a generous community member who volunteered his excavating equipment (and time).
The planting initiative aims to prevent shoreline erosion, promote the growth of native species, increase wildlife habitat, and improve the water quality of Memorial Pond and Lake Hopatcong. Funding for this project was secured through a grant from the New Jersey Department of Environmental Protection, awarded to the Lake Hopatcong Commission in partnership with the Lake Hopatcong Foundation.
Memorial Pond is a 0.3-acre stormwater runoff basin that gradually releases into Glen Brook, which then flows into Lake Hopatcong. The pond receives sheet flow of stormwater from the adjacent road, which contributes to nutrient and sediment loading, thus locally reducing water quality in Memorial Pond and ultimately the waters of Lake Hopatcong.
Memorial Park, which includes Memorial Pond and Glen Brook, was identified by Princeton Hydro and the Lake Hopatcong team as a priority site for improvement, targeting initiatives that reduce pollutants and excessive nutrients entering into Lake Hopatcong.
Additionally, the pond’s steeply-sloped shoreline was bare and only stabilized with large rocks at the base of the banks. In the absence of stabilizing vegetation, the pond’s banks were experiencing erosion, and there was some concern about a few mature trees along the shoreline potentially falling into the pond.
The photos above were taken in April 2023 before the planting initiative.
The plant selection and layout were designed taking into account the steep slope and presence of mature, existing trees as well as focusing on regionally native plant species that will thrive and help stabilize the eroding shoreline. The planting team, led by Princeton Hydro Landscape Architect Jamie Feinstein, RLA and Aquatics Project Manager Pat Rose, was given precise instructions on how to install the plants to eliminate washouts and ensure the root systems can embrace the soil and hold it in place.
A variety of native herbaceous plants and shrubs were chosen for the site, including pennsylvania sedge, slender mountain mint, blue flag iris, sweet azalea, smooth hydrangea, and maple-leaved viburnum.
The plants will help reduce stormwater flow, absorb excess nutrients, prevent erosion, and ultimately decrease sedimentation to the pond, while creating a visually pleasing addition to the park and providing a habitat for pollinators and birds. Overall, this project promotes a healthier and more balanced ecosystem in Memorial Park.
The photos above were taken in July 2023 immediately after the planting initiative.
The installation of these beneficial plants is part of a series of water quality initiatives on Lake Hopatcong funded by a NJDEP Freshwater Harmful Algal Bloom (HAB) Prevention & Management Grant and 319(h) Grant awarded to Lake Hopatcong Commission in partnership with the Lake Hopatcong Foundation.
Additional initiatives included in the watershed implementation and HABs management plan are, the installation of:
floating wetland island (FWI), which are a low-cost, effective green infrastructure solution designed to mimic natural wetlands in a sustainable, efficient, and powerful way. FWIs improve water quality by assimilating and removing excess nutrients; provide valuable ecological habitat for a variety of beneficial species; help mitigate wave and wind erosion impacts; provide an aesthetic element; and add significant biodiversity enhancement within open freshwater environments;
biochar filtration bags, which improve water quality by removing phosphorus from waterbodies. Biochar can be placed in floatation balls, cages, or sacks, which are then tethered along the shoreline and in critical locations throughout the waterbody; and
nanobubble aeration system, which increases the concentrations of dissolved oxygen in the water, prevents stagnation of water, increases circulation, disrupts thermal stratification which provides “through-column” mixing, and minimizes the occurrence of HABs.
“Paired with biochar filters attached to buoys in the pond and continued monitoring and maintenance of the plantings by the DPW, these steps will set a healthy precedent for what can be achieved through working together with funders, local partners, science, and landscape architecture,” said Feinstein, who sourced plant material, provided logistics and co-led the planning and volunteer planting event along with Rose.
Princeton Hydro's Landscape Architect, Cory Speroff PLA, ASLA, CBLP, designed the planting plan, and Will Kelleher and Jackson Tilves from the Aquatics Team participated in the plant installation event with Feinstein.
Princeton Hydro is also authoring and supplying a maintenance manual that provides guidance on seasonal care of the plantings, when to remove the herbivory protection fencing, pruning, watering, and other activities that support the long term success of the planting initiative.
“This collaborative effort to enhance water quality serves as a prime example of how seemingly simple actions can have a meaningful impact on safeguarding our water resources for the benefit of future generations,” said the Lake Hopatcong Foundation.
The photos above from left to right: June 2023 before the planting; July 2023 during the planting (photo by Lake Hopatcong Foundation Executive Director Kyle Richter); and July 2023 immediately after the planting.
Princeton Hydro has been working on Lake Hopatcong, New Jersey’s largest Lake, for 30+ years, restoring the lake, managing the watershed, reducing pollutant loading, and addressing invasive aquatic plants and nuisance algal blooms. To read about some of the other projects we’ve recently worked on at Lake Hopatcong, click here.
Exciting changes have unfolded at Kol Emet, a Reconstructionist Congregation in Yardley, Bucks County, Pennsylvania. The campus’ exterior lands have undergone a remarkable transformation, blossoming into an enchanting and peaceful place for community member gatherings, and a wildflower meadow.
Princeton Hydro partnered with Congregation Kol Emet to design and implement the synagogue's 10-acre campus transformation. The Princeton Hydro team provided green infrastructure engineering, landscape architecture, and construction services aimed at enhancing the usability and welcoming atmosphere of the synagogue, and creating a sustainable outdoor solution in the event of future pandemics, and a place to connect with the natural environment that surrounds the property. The design provides a net positive impact by reducing flooding in the community and improves water quality by augmenting stormwater management and biodiversity throughout the property.
"Our vision surpassed mere construction of a gathering space," said Geoffrey M. Goll P.E., President of Princeton Hydro, a congregant of Kol Emet, Executive Board Member, and point person for the project. "We wanted to create a harmonious union between the synagogue campus and the surrounding preserved woodlands, cultivating a serene haven where congregants can unite, celebrate, and worship, while also enhancing the ecological functionality and biodiversity of the landscape. This was a realization of the vision of the Founders of Kol Emet and the labor and financial support of many members of the Board, past and present, and a generous donation by a longtime supporter of the community. The outdoor sanctuary was named in honor and memory of a founding member and former President, Geri Shatz, who was a staunch supporter of the Jewish community and advocate for the mission of Kol Emet. She lived the ideals of community and contribution. I am proud of the extraordinary transformation that’s been achieved."
The Kol Emet Reconstructionist Congregation, is a 501(c)3 religious organization, founded in 1984. While a center of worship for its members, it is much more than that. Kol Emet is a community of people who care about improving the world around them through social action and environmental protection.
The sentiment of "Tikkun Olam" is embodied by Kol Emet and the committee that spearheaded the project, working directly with the Princeton Hydro team to bring the project goals to fruition. The modern interpretation of the Hebrew phrase “Tikkun Olam,” is “action intended to repair and improve the world.” The campus restoration project brings the concept of “Tikkun Olam” to life.
Princeton Hydro Landscape Architect Cory Speroff, PLA, ASLA, CBLP is the project’s lead designer. The project included landscape design and planting that incorporates native and sustainable trees and shrubs; significant upgrades to the existing stormwater management basin, including the conversion of low-flow channels, impervious surfaces, and turf-covered areas to native grassland and wildflower habitat; and the development of the “Geri Shatz Outdoor Contemplative Space."
Cory’s design inspiration for the Geri Shatz Outdoor Contemplative Space is modeled after the Hebrew term “etz chaim” or “Tree of Life.” In Judaism, the Tree of Life has a number of meanings, both literal and figurative. In the Kabbalah, the Tree of Life represents the connection between heaven and earth, wisdom and knowledge, and the interconnectedness of all living things. It is visually represented as a diagram that looks much like a tree with 10 nodes and 22 lines. Cory’s design for the community space uses strategically placed trees to mimic the Tree of Life and aims to promote community connection and a connection to the surrounding natural landscape.
The contemplative space consists of a bimah, seating to accommodate at least 80 people, and a beautiful array of native trees and flowering shrubs, including black gum, silver birch, and Virginia sweetspire.
Cory’s design for the land surrounding the contemplative space improves flood resilience; controls stormwater runoff volume and promotes groundwater recharge; boosts safety features of the campus; and enhances habitat for pollinators, native plants, and other important species. The wildflower meadow was seeded with a variety of native plants, including purple love grass, common milkweed, wild bergamot, and blue wild indigo.
“During the height of the COVID-19 pandemic, it felt like the only way to see our loved ones was to be outside, and during these backyard and front porch gatherings many people re-discovered their love for the outdoors,” said Cory. “In talking with the Committee, there was a desire to create an outdoor sanctuary where the congregation could gather and continue that re-discovery. I believe that through the careful consideration of symbolic elements and thoughtful design choices, we’ve created a space that can inspire introspection, connection, and a sense of harmony with both nature and faith.”
Funding for the project came from the Congregation Kol Emet’s “Our Heart. Our Home” capital campaign, a $750,000 campaign focused on upgrading four key aspects of the synagogue: social hall, HVAC upgrades, indoor sanctuary, outside school, and the new outdoor sanctuary. The outdoor sanctuary and ecological uplift to the 10-acre campus is a primary piece of the campaign and was made possible by the generous donations of several Kol Emet members.
Stan Shatz bestowed a bounteous donation in memory of Geri Shatz, which made possible the creation of the “Geri Shatz Outdoor Contemplative Space.”
The following families also contributed to the funding of the Geri Shatz Outdoor Contemplative Space: Laurel & Kevin Bloch, Barbara & Debra Fogel and Family, Jill & David Gordon, Annie & Ryan Kubanoff and Family, and Teddi & Josh Matisoff and Family.
The Princeton Hydro team is honored to have worked with Kol Emet on this important and inspirational project.
Congregation Kol Emet came together on Sunday, June 4, 2023 for a celebration and ribbon-cutting ceremony to mark the completion of the outdoor sanctuary project. Here are a few photos from the joyous event:
Princeton Hydro is an expert in engineering, ecological restoration, and landscape architecture, and we’ve been incorporating green stormwater infrastructure and nature-based solutions into our designs for decades. Click here to read about the landscape restoration and stormwater management project we designed and implemented in Thompson Park, a 675-acre recreation area in Middlesex County, New Jersey.
Your Full Name * Phone Number * Your Email * Organization Address Message *
By EmailBy Phone
Submit
Δ
Couldn’t find a match? Check back often as we post new positions throughout the year.
PRINCETON HYDRO
PRINCETON HYDRO