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We're pleased to announce the release of the "New Jersey Nature-Based Solutions: Planning, Implementation, and Monitoring Reference Guide," a free resource that provides a comprehensive roadmap to incorporating nature-based solutions (NBS) into infrastructure, construction, restoration, and resilience projects across the state.
Created by the Rutgers University New Jersey Climate Change Resource Center with support from The Nature Conservancy in New Jersey, the guide compiles current research, case studies, best practices, practical tools, science-based strategies, and funding resources to "inform and empower readers to implement and seek funding for NBS."
Click here to view and download the guide now.
As the guide states, "nature-based solutions (NBS) are defined as actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously benefiting people and nature." (IUCN 2024)
Whether you're a municipal planner, community leader, contractor, public- or private-sector professional, or an academic, new to NBS or experienced in large-scale restoration projects, the guide offers value at every level with practical instruction that spans the full project lifecycle, from planning and permitting to funding and long-term monitoring. While the content is tailored to New Jersey's diverse landscapes, the guide's insights and approaches are broadly applicable to regions with similar ecosystems, from Massachusetts to Virginia.
The guide also includes insights on how to address equity considerations and foster meaningful community engagement, helping users implement NBS that are both impactful and inclusive.
Princeton Hydro was proud to contribute technical expertise to this important effort. Our Director of Restoration & Resilience, Christiana L. Pollack, CERP, CFM, GISP, participated on the guide's steering committee, and our team provided informational resources, including content and case studies on invasive species management, wetland and floodplain enhancement, and dam and culvert removal to restore rivers and improve fish passage. These contributions along with those from many other participants, reflect the collaborative nature of the guide and the collective commitment to advancing NBS across the state.
The guide's easy-to-follow format includes four key sections:
Whether you're just beginning to conceptualize a project or deep into project implementation, this guide is an invaluable addition to your toolbox. We encourage you to explore, download, and share it widely! Click here to access the guide now.
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 in Luzerne County, Pennsylvania, Harveys Lake spans 622 acres and is the largest natural lake by volume in the Commonwealth. Beyond its scenic beauty and popularity as a recreational destination, the lake plays a critical ecological role in the region.
Harveys Lake forms the headwaters of Harveys Creek, which flows into the Susquehanna River and ultimately the Chesapeake Bay. As such, it is part of the greater Susquehanna River Valley and contributes to the health of the Chesapeake Bay watershed. The lake and its outflow are designated High Quality – Cold-Water Fisheries, supporting sensitive aquatic life, providing vital cold-water habitat, and contributing to regional biodiversity.
Given its ecological significance and its connection to regional waterways, efforts to manage stormwater and reduce nutrient pollution in the Harveys Lake watershed are more than just local improvements, they are integral to protecting downstream water quality all the way to the Chesapeake Bay.
In 2022, building on decades of water quality initiatives, the Borough of Harveys Lake launched a forward-thinking pilot project to enhance stormwater treatment using innovative nutrient-filtering technologies. Supported by funding from the National Fish and Wildlife Foundation (NFWF) Chesapeake Bay Small Watershed Grant Program and designed and implemented in partnership with Princeton Hydro, this project explores the use of biochar and EutroSORB® filtration media to capture dissolved nutrients, an important step toward improving water quality and meeting regulatory goals.
This blog explores the local history of water management at Harveys Lake, the science behind this novel pilot approach, and the broader implications for watershed protection across the region.
Once a remote, wooded landscape, the Harveys Lake area was settled in the early 19th century and gradually developed into a hub for timbering and milling. By the late 1800s, the lake was regularly stocked with game fish, and with the arrival of the railroad in 1887, it quickly became a popular summer destination. The shoreline soon featured hotels, restaurants, and even an amusement park.
As the community flourished, the lake's natural systems began to show signs of strain. Like many waterbodies across the country, Harveys Lake faced growing water quality challenges driven by stormwater runoff, nutrient pollution, and a lack of formal environmental protections. By the 1960s, declining water clarity and seasonal algal blooms began to impact recreation, contributing to the lake’s gradual transition from a bustling public getaway to a primarily residential community.
A significant shift occurred following the passage of the U.S. Environmental Protection Agency’s Clean Water Act of 1972. Harveys Lake established a municipal sewer authority, and construction began on a utility line around the lake's perimeter to reduce point-source pollution. Still, algae blooms persisted throughout the 1980s, fueled by nonpoint sources such as stormwater runoff, lawn fertilizers, and waterfowl droppings.
In 1994, a Phase I Diagnostic Feasibility Study was conducted that formally identified Harveys Lake as impaired due to recurring algal blooms linked to elevated nutrient levels. Following this study, a Total Maximum Daily Load (TMDL) was established, and management efforts were initiated to meet long-term water quality goals.
Since 2003, the Harveys Lake watershed has undergone extensive stormwater management efforts, including the installation of numerous manufactured treatment devices (MTDs) to reduce pollutant loading. Most of these MTDs are nutrient separating baffle boxes (NSBBs), chosen due to the watershed’s steep slopes, dense residential development, and shallow bedrock. The first NSBB, pictured below, was installed at Hemlock Gardens:
In 2009, the Borough of Harvey’s Lake worked with Princeton Hydro to develop a Stormwater Implementation Plan that laid the foundation for future restoration efforts. Over the following years, the Borough of Harveys Lake, supported by state and regional grants, implemented 34 stormwater best management practices (BMPs) and installed four floating wetland islands throughout the watershed.
These projects were strategically designed to reduce nutrient loading, enhance water quality, and move the lake closer to achieving its TMDL targets. Click here to read more about these efforts.
While NSBB stormwater BMPs are highly effective at capturing sediments and associated pollutants, they are limited in their ability to remove dissolved nutrients, particularly nitrogen and phosphorus. This is evident in the Harveys Lake Watershed, where NSBBs remove approximately 70% of total suspended solids (such as sediment and plant debris), 35% of total phosphorus, and 0% of total nitrogen. To address this gap and improve overall nutrient removal efficiency, the Borough of Harveys Lake received funding from the NFWF Chesapeake Bay Small Watershed Grant Program to augment existing MTD stormwater BMPs using new filter technologies.
Partnered with Princeton Hydro for design, implementation, and technical support, the Borough launched a unique pilot project involving the installation of biochar and EutroSORB® (manufactured by SePRO Corporation) to evaluate the effectiveness of these two innovative materials in removing dissolved phosphorus and total nitrogen from stormwater runoff before it reaches Harveys Lake.
Biochar, a carbon-rich material derived from plant biomass, is valued for its high surface area and nutrient-adsorption capacity. EutroSORB® is a manufactured media specifically engineered to bind and retain dissolved phosphorus with demonstrated effectiveness in aquatic systems.
Filter socks filled with either biochar or EutroSORB® were installed at key stormwater outfalls and stream inlets that drain directly to the lake. At four NSBB sites, the socks were secured beneath manhole covers using a rope-and-carabiner system designed for easy, seasonal replacement. Each sock weighs approximately 50–60 pounds when saturated and was carefully positioned to avoid dislodgement or blockage of outlet pipes during high-flow events.
At the Hemlock Gardens site, which features a larger, multi-tray baffle box, twelve filter socks were installed across two horizontal trays to maximize contact time between stormwater and the filter media.
By integrating these innovative filter techniques into the existing BMP infrastructure, the Borough of Harveys Lake is taking a proactive, science-based approach to nutrient reduction and long-term water quality improvement.
Princeton Hydro implemented a comprehensive water quality monitoring program in the Harveys Lake watershed to assess the real-world performance of the biochar and EutroSORB® filtration systems under varying hydrologic conditions, with a particular focus on dissolved nutrients that contribute to eutrophication.
Six stormwater monitoring stations were established at locations where biochar or EutroSORB® were deployed within NSBBs or stream inlets. Each site included paired upstream (pre-treatment) and downstream (post-treatment) sampling points to capture the nutrient concentrations entering and exiting the filtration media.
Stormwater sampling was conducted during six separate rainfall events between March and April 2025. At each location, during storm flow conditions, discrete grab samples were collected via a portable polyethylene sampling pole and analyzed for key water quality parameters.
Beyond concentration-based comparisons, Princeton Hydro used empirical monitoring data to model pollutant loads upgradient and downgradient of the filtration media. These load estimates provide insights into pollutant removal effectiveness on a mass basis, with a focus on:
Emphasis was placed on SRP—the biologically available form of phosphorus most readily assimilated by algae and a key driver of harmful algal blooms and eutrophication. Because phosphorus is the target pollutant in Harveys Lake’s TMDL, SRP reduction serves as a critical indicator of the filtration media’s performance and its potential role in long-term water quality management strategies.
Overall, the study revealed variable but promising results across media types and installation locations:
These early findings suggest that both EutroSORB® and biochar hold promise as cost-effective tools for reducing soluble phosphorus in stormwater runoff. Additionally, observed differences in removal efficiency, based on installation context (NSBB vs. stream), filter media volume, and site-specific hydrologic conditions, underscore the importance of continued monitoring and system refinement.
As part of the project’s commitment to long-term sustainability and public education, a native pollinator garden was established near the Harveys Lake Department of Public Works garage, adjacent to the Little League fields.
After the final sampling in April 2025, the nutrient-saturated biochar and EutroSORB® socks were removed from the stormwater treatment systems. The spent biochar, having captured phosphorus and nitrogen from runoff, was repurposed as a soil amendment to enrich a 500-square-foot planting area. This repurposing effort served a dual purpose: demonstrating a closed-loop approach to managing excess nutrients while also creating a community-oriented space that supports local biodiversity.
The Harveys Lake Environmental Advisory Council volunteered to help plant the garden, installing 450 native plant plugs across nine species including Foxglove Beardtongue, Clustered Mountain Mint, Blue Wild Indigo, and Common Yarrow to attract pollinators such as butterflies, bees, and songbirds.
Designed by Princeton Hydro, the pollinator garden serves as both an ecological asset and an educational tool. Its prominent location next to the ballfields encourages community engagement, and an interpretive sign on-site helps visitors understand the garden’s purpose and its connection to local water quality initiatives. The sign features a QR code linking to an interactive ArcGIS StoryMap, developed by Princeton Hydro, which explores the broader context of the project. It draws connections between nutrient management efforts in Harveys Lake and similar challenges facing the entire Chesapeake Bay watershed, emphasizing how local actions contribute to regional water quality improvements. To support public outreach, the StoryMap was also shared on the Borough’s website, making this educational resource widely accessible to the community.
It is important to note that while this project illustrates a successful example of biochar reuse, all reuse applications must be assessed on a case-by-case basis. For example, biochar exposed to hazardous pollutants is not suitable for soil use. In this case, the biochar had only been used to absorb excess nutrients, making it appropriate for the garden setting.
Supported by the U.S. Environmental Protection Agency and the NFWF’s Chesapeake Bay Stewardship Fund, which promotes community-based conservation strategies to protect and restore Chesapeake Bay’s natural resources, this project was designed with scalability in mind. A core objective was to evaluate whether these filtration media could be more broadly implemented throughout the Chesapeake Bay watershed as a low-cost, community-integrated strategy for achieving water quality goals.
Through continued innovation and shared learning, small-scale efforts like this can drive large-scale impact, proving that effective water quality solutions don’t have to be costly or complex. The Harveys Lake model offers a replicable framework that communities across the region can adopt and adapt, empowering local action that contributes meaningfully to the restoration and resilience of Chesapeake Bay.
The Borough of Harveys Lake, in partnership with Princeton Hydro, launched a new interactive ArcGIS StoryMap that chronicles the community’s long-standing commitment to water quality and showcases a recently completed pilot project aimed at reducing stormwater nutrient pollution.
This engaging digital resource combines maps, multimedia, charts, diagrams, and narrative storytelling to bring the science and history of Harveys Lake’s multi-year environmental restoration efforts to life. It explores both the local impact and the broader significance of these initiatives, drawing connections to similar water quality challenges throughout the Chesapeake Bay Watershed.
Designed with accessibility in mind, the StoryMap invites users to explore project sites, restoration progress, and technical details without the need for specialized GIS training or software. Interactive features, such as zoomable maps, clickable pins, and site-specific details, offer an intuitive, user-friendly experience.
More than just a visualization tool, the StoryMap serves as a community-education and engagement platform. It highlights how local stormwater management strategies, like those implemented at Harveys Lake, can drive positive, region-wide change, underscoring the vital role of place-based solutions in improving watershed health across the Chesapeake Bay region.
The StoryMap begins with an exploration of the Chesapeake Bay Watershed—one of the most ecologically and economically significant estuaries in the United States. This region faces complex environmental challenges, including nutrient pollution, habitat loss, and climate change impacts. Over the past several decades, a wide range of stakeholders have engaged in coordinated restoration efforts to protect and improve water quality across the watershed.
Using interactive maps, expandable sections, and rich visuals, this introductory portion of the StoryMap places Harveys Lake in a broader regional context. It sets the stage for understanding how local action, such as nutrient reduction at Harveys Lake, plays a critical role in supporting the health of the entire Chesapeake Bay ecosystem.
The next section, “Harveys Lake: A Case Study,” highlights the Borough's ongoing dedication to protecting the lake and improving water quality through science-based solutions and collaborative efforts. The StoryMap provides:
The final section of the StoryMap dives into a 2025 pilot initiative that used biochar and EutroSORB® filter media to reduce dissolved phosphorus and total nitrogen from stormwater runoff. Organized into subsections—Project Information, Methodology, Results and Discussion, Pollinator Garden, and Future Implications—the StoryMap offers a detailed look at this innovative nutrient-reduction strategy and its potential for replication across the Chesapeake Bay watershed.
In addition to detailing the pilot project, this section also spotlights the creation of a native pollinator garden, planted using the spent biochar as fertilizer. This closed-loop approach not only reinforces the project’s long-term ecological value but also demonstrates how thoughtful design can deliver multiple environmental benefits while cultivating a vibrant community-oriented space that supports local biodiversity.
To extend the impact of this initiative, the StoryMap was provided to the Harveys Lake Borough Environmental Advisory Council (EAC) and is publicly accessible via the Borough’s website. A QR code linking to the StoryMap is also featured on the new pollinator garden sign at the project site, allowing visitors to engage with the digital experience in real time.
By blending maps, visuals, and interactive storytelling, this StoryMap serves as both an educational tool and a digital archive of the latest Harveys Lake water quality project and its long history of stewardship. We invite you to explore this engaging platform and see firsthand how thoughtful, science-based restoration is shaping a healthier future for Harveys Lake, and the entire Chesapeake Bay watershed.
This material is based on work supported by the U.S. Environmental Protection Agency (Assistance Agreement No. CB96358101) and the National Fish and Wildlife Foundation’s Chesapeake Bay Stewardship Fund, which supports community-based strategies to conserve and restore the Chesapeake Bay’s natural resources. Click here to learn more information about the grant program.
Click here to learn more about Harveys Lake or how to get involved in a Harveys Lake Borough Environmental Advisory Council stewardship program.
In urban areas, streams have often been buried beneath streets, buildings, and infrastructure, cutting them off from the natural ecosystem. However, a growing movement towards "daylighting" streams—uncovering and restoring these buried watercourses—has proven to be an innovative solution for improving water quality, reducing flood risks, restoring fish passage, and creating healthier habitats. Princeton Hydro has been at the forefront of these efforts, bringing expertise in ecological restoration and water resource management to daylighting projects across New Jersey.
Daylighting is the process of removing obstructions and impervious surfaces from a buried stream or river, restoring it to a more natural state. Often, streams were diverted underground to make way for urban development. Daylighting involves reversing this process, bringing the water flow back above ground where it can interact with the natural environment. The result is a newly visible, revitalized waterway that reconnects the stream to its surrounding ecosystem. This process not only improves stormwater management but also enhances urban spaces and promotes healthier habitats.
Daylighting streams offers numerous advantages to both the environment and local communities. Some key benefits include:
Princeton Hydro has successfully completed numerous daylighting projects that demonstrate the transformative power of restoring natural waterways. By leveraging innovative engineering and ecological practices, these projects restored the natural flow of waterways and enhanced the surrounding landscape. Let’s take a closer look at two examples:
In the heart of Trenton, NJ, Princeton Hydro undertook a comprehensive stream restoration. The City of Trenton, as part of a larger urban revitalization and brownfield redevelopment project, sought to restore the stream, Petty’s Run, which had long suffered from typical urban afflictions: pollution, flooding, and heavy debris accumulation.
Princeton Hydro developed a green infrastructure design that addressed these challenges holistically. The design included removing from the stream channel heavy debris, contaminated soils, and the concrete remains of previous development. The team also replaced the restrictive upstream road crossing with a pedestrian bridge, enhancing both the stream’s flow and the community’s connectivity. A significant aspect of the project involved daylighting the 250-foot underground portion of Petty’s Run, restoring it to a natural, open flow while creating an adjacent floodplain meadow to manage stormwater and provide habitat.
The project improved stormwater management, enhanced the landscape’s biodiversity, added habitat value, and established a new public green space with walking trails, which now serves as both an ecological asset and a recreational area for the community. This project earned both the Phoenix Award for Brownfield Redevelopment and the Bowman’s Hill Land Ethics Award.
Thompson Park, a sprawling 675-acre recreational area in Middlesex County, NJ, boasts a variety of amenities, including hiking trails, ballfields, and a zoo that is home to over 50 geese and fowl, goats, and approximately 90 deer. The streams within the park faced challenges, particularly in the areas surrounding the zoo’s enclosures, including erosion and compromised water quality.
In order to increase channel stability, decrease erosion, improve water quality and ecological function, and reduce the pollutants originating from the zoo, a stormwater management treatment train was designed and constructed.
Middlesex County Office of Parks and Recreation and Office of Planning, New Jersey Department of Environmental Protection, South Jersey Resource Conservation and Development Council, Middlesex County Mosquito Extermination Commission, Freehold Soil Conservation District, Rutgers Cooperative Extension, Enviroscapes and Princeton Hydro worked together to fund, design, permit, and construct numerous stormwater management measures within Thompson Park.
One of the key project initiatives involved daylighting a section of a 24-inch reinforced concrete pipe (RCP) that had previously conveyed stormwater underground. Daylighting the stream, widen the stream channel, improved stormwater absorption, reduced erosion, helped restore the stream’s natural gradient, and improved aquatic habitat.
This multi-faceted restoration project improved stream function and created a more sustainable environment for both zoo inhabitants, the park’s visitors, and the watershed.
Princeton Hydro’s President and Founding Principal, Geoffrey M. Goll, PE, recently shared his expertise in stream restoration during a "Daylighting Streams: Design & Engineering" webinar hosted by The Watershed Institute. The webinar explored the process of uncovering and restoring buried watercourses. Moderated by Susan Bristol, The Watershed Institute Municipal Policy Specialist, the webinar featured experts Vince Sortman, Biohabitats Senior Fluvial Geomorphologist; Warren T. Byrd, Jr., FASLA, Founding Partner of Nelson Byrd Woltz Landscape Architects & Professor Emeritus, University of Virginia; and Geoffrey. The webinar provided valuable insights into the challenges and benefits of these projects, highlighting the importance of hazard mitigation, maintenance, and community involvement in successful daylighting initiatives. The event underscored the significance of daylighting in enhancing both urban infrastructure and natural ecosystems.
Daylighting streams is a forward-thinking approach to urban water management that brings immense benefits to the environment and local communities. As daylighting continues to gain recognition as an essential tool for watershed restoration, Princeton Hydro remains a trusted leader in the field, combining innovative design with environmental stewardship.
New Jersey Department of Environmental Protection (NJDEP) 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 Firehouse, celebrated the Lambertville's commitment to improving stormwater management, addressing flooding, protecting local waterbodies, increasing storm resilience, and mitigating the impacts of climate change.
In a press release announcing the award, Commissioner LaTourette said, “Modernization of stormwater management strategies and infrastructure is critical to mitigating flooding that is severely impacting communities across New Jersey. My DEP colleagues and I applaud Lambertville for paving the way for others to follow in managing stormwater more effectively.”
The "Our Water’s Worth It" campaign, launched by NJDEP earlier this year, aims to raise awareness about the importance of protecting New Jersey’s water resources. The campaign highlights municipalities, water systems, and others who go above and beyond in water resource management and infrastructure improvements. Lambertville’s forward-thinking approach to stormwater management, particularly in meeting permitting requirements ahead of schedule, earned the city this well-deserved recognition.
At Princeton Hydro, we are proud to support the City of Lambertville in its stormwater management initiatives. Our team has been working closely with Lambertville to design projects that not only mitigate flooding but also enhance the surrounding natural environment.
During the award ceremony, Senior Project Manager and Professional Engineer, Sean Walsh, PE, said: “We are honored to be here today alongside NJDEP and the City of Lambertville celebrating Lambertville's remarkable achievement in receiving the 'Our Water's Worth It' trophy. It's particularly meaningful that this recognition comes during Climate Week, underscoring the importance of local action in addressing global environmental challenges.”
Earlier this year, the Princeton Hydro team completed a comprehensive Stormwater Utility Feasibility Study, which provided critical insights into Lambertville’s current stormwater management capacity and forecasted future needs.
Among the ongoing projects, Princeton Hydro is evaluating solutions for capturing runoff and reducing flooding in Lambertville's Music Mountain area, a critical greenspace in the heart of the city. This steep, wooded hillside, home to popular nature trails, serves as a cherished spot for after-school exploration, dog walking, and outdoor recreation. Music Mountain also plays a critical role in the city’s stormwater management system, acting as a natural buffer to protect lower-lying areas from flash flooding caused by runoff from the residential neighborhoods above. However, storm sewer outfalls discharging into the hillside have created deep erosion gullies, and during heavy rain events, the runoff has flooded the Fire Department. In collaboration with the City and the Fire Department, Princeton Hydro is designing a comprehensive solution that includes both the installation of a piped stormwater system and enlarging the inlet at the base of the mountain to better capture surface water runoff.
Additionally, on the Closson Farm property, Princeton Hydro is designing a riparian restoration project to manage the effects of increasing storm intensity. Funded by the National Fish and Wildlife Foundation, this project will result in 4.6 acres of restored floodplain, 300 trees planted, creation of wildlife habitat, measurable sediment and nutrient reduction, reduced stormwater runoff, community engagement, and new walking paths for recreation.
“Together with Lambertville, we are taking essential steps to enhance the city’s infrastructure and safeguard the community against future flooding. Our partnership reflects a shared commitment to protecting the environment and promoting resilience,” said Princeton Hydro’s Director of Restoration & Resilience, Christiana Pollack, CFM, GISP.
By embracing innovative stormwater solutions, Lambertville is not only enhancing its infrastructure but also setting a benchmark for resilience and environmental stewardship across New Jersey. This recognition reflects the city’s commitment to proactive flood management and sustainability, serving as an inspiration for other communities.
Princeton Hydro is honored to partner with the City of Lambertville on these important efforts. We extend our heartfelt congratulations on this well-deserved recognition and are excited to continue our collaboration on future projects that will further strengthen the city's resilience and protect its vibrant neighborhoods.
To learn more about NJDEP’s "Our Water’s Worth It" campaign, watch the video below:
New Jersey’s water-related infrastructure is a complex system, constantly facing the challenges posed by stormwater runoff and working to properly manage it. Stormwater management isn’t just about handling rainfall; it’s a critical aspect of improving water quality and mitigating flood risks. In New Jersey, where urbanization and rainfall patterns intersect, managing stormwater is more than just a priority; it’s a necessity. To learn more about stormwater management solutions, check out our blog: "In the Eye of the Storm: Exploring A Stormwater Utility in New Jersey."
Mercer County Park, spanning over 2,500 acres across the Townships of West Windsor, Hamilton, and Lawrence, is a treasured natural resource. Like many waterbodies throughout New Jersey, some of the lakes within Mercer County Park have been increasingly affected by harmful algal blooms (HABs) in recent years. In response to the growing frequency, duration, and severity of these blooms, the Mercer County Park Commission (MCPC) has intensified its efforts to enhance the overall health of its lakes.
To address these challenges, the County of Mercer tasked the MCPC with developing a comprehensive Lake and Watershed Management Plan. The ultimate goal is to ensure the health, stability, and sustainability of the park's aquatic ecosystems, thereby enhancing the recreational experience for park users. In this endeavor, the MCPC has partnered with Princeton Hydro to bridge gaps in the existing data and create a thorough management plan.
The plan documents the current conditions of waterbodies within the park, including Mercer Lake, which is the largest, and its surrounding watershed; identifies and prioritizes existing and potential water quality challenges; and provides targeted recommendations for treatment and restoration.
Princeton Hydro conducted a detailed analysis of the lakes' ecological health, including water quality monitoring, bathymetric mapping, and assessment of hydrologic and pollutant budgets. These comprehensive efforts have culminated in a robust management plan designed to protect and improve the lakes' ecological balance and recreational value.
While Mercer Lake is a key focus, Princeton Hydro's commitment extends beyond this single waterbody. Recognizing the interconnected nature of the county's aquatic ecosystems, the team conducted similar analysis and developed Lake and Watershed Management Plans for three additional lakes in other parks within Mercer County.
Each of these lakes, like Mercer Lake, faces unique challenges related to maintaining water quality, protecting ecological balance, and mitigating HABs. By applying a comprehensive approach tailored to the specific conditions and needs of each lake, Princeton Hydro aims to enhance the overall health of these vital resources.
Let's dive into the details of Mercer Lake's plan!
The first crucial step in developing Mercer County Park's comprehensive lake management plan involved a thorough review of historical data obtained from various sources, including the County, New Jersey Department of Environmental Protection (NJDEP), New Jersey Department of Transportation (NJDOT), and U.S. Geological Survey (USGS). This review was essential for capitalizing on established water quality trends, identifying recurring problems, and evaluating the success of previous restoration efforts.
The historical data review spanned an impressive range of years from 1963 to 2016, though it did contain some significant gaps. Despite these gaps, the long-term data provided invaluable insights into the lake's ecological history. By integrating reliable data from past studies, the team could complement their field efforts with supplemental information.
Princeton Hydro examined data on Mercer Lake, a key focus of the management plan initiative, and on all streams within each watershed that feed into the lake. This included any available surface water data from the USGS, a standard approach in aquatic system studies. By analyzing these data, the team identified trends in water quality, highlighted persistent issues, and assessed the effectiveness of past restoration efforts.
This comprehensive historical data review set the stage for a robust watershed assessment, ensuring that the management plan would be informed by a solid foundation of past knowledge.
A bathymetric survey is a scientific method used to map the depths and topography of waterbodies, providing detailed information about the underwater terrain and the distribution of sediments. This survey is crucial for understanding various aspects of a lake's ecosystem, including sediment thickness, water volume, and potential areas for dredging. The data gathered from a bathymetric survey helps in making informed decisions regarding the restoration and protection of lakes.
Princeton Hydro conducted the bathymetric survey using a calibrated sounding rod for shallow areas and a dual-frequency echo sounder with GPS for deeper regions. The sounding rod was employed in areas with water depths of 12 inches or less and where sediment composition hindered echo sounding. The echo sounder, a Knudsen Engineering model 1612, used high and low frequencies to distinguish the top and bottom of sediment layers. Data points were collected along predetermined transects spaced 150 feet apart, running from shoreline to shoreline in a north-south direction.
Once fieldwork was completed, the collected data was processed using Hypack Max software. This involved editing the raw sounder data to correct errors such as double reflections and interference from aquatic vegetation. The cleaned data was exported to ArcGIS for further analysis and mapping.
The results of the bathymetric survey revealed that Mercer Lake, a key focus of the lake management plan, covers a surface area of approximately 287 acres and is primarily an oval-shaped impoundment. The lake receives inflow from Assunpink Creek and its tributaries and discharges water westward, eventually reaching the Delaware River, Delaware Bay, and the Atlantic Ocean.
Mercer Lake was found to be relatively shallow, with a mean depth of 8.9 feet and a maximum depth of 18.5 feet. The total volume of water in the lake was estimated at around 2,560 acre-feet, or 834.2 million gallons. The survey also indicated significant sediment deposition in the eastern portion of the lake, with a total sediment volume of approximately 855,325 cubic yards. This pattern is likely due to the lake's role as a settling area for sediment carried by tributary inflows and stormwater discharges, which transport debris, leaf litter, and other materials into the lake.
Below is an image of the Bathymetric Survey that provides a detailed view of the sediment thickness contours measured in feet throughout Mercer Lake:
By establishing a detailed understanding of Mercer Lake's depth and sediment distribution, the bathymetric survey provides a robust foundation for the comprehensive lake management plan, informing long-term management decisions. The bathymetric data collected is also essential for evaluating the need for dredging, understanding aquatic plant colonization patterns, and predicting the lake's response to incoming nutrients, helping to guide restoration and protection efforts.
Hydrologic and Pollutant Loading Analysis is crucial for identifying the sources and impacts of pollutants entering a waterbody. It involves delineating watersheds, assessing hydrologic data, and evaluating nutrient loads.
For Mercer Lake, Princeton Hydro conducted an extensive analysis using tools such as USGS StreamStats and Stroud Research Center’s Model My Watershed®. This study provided a detailed understanding of the water and pollutant dynamics within the Mercer Lake watershed. The map below offers an aerial view of the watershed, illustrating the various types of land cover present within the area:
Runoff varied considerably between different sub-watersheds due to factors like land cover types, land-use consumption, impervious surfaces, and topography. Variations in elevation change also determine the impact runoff has on soil erosion, with steeper slopes causing higher erosion rates, especially if little vegetation is present. The chart below shows the various types of soil coverage in areas throughout the Mercer Lake watershed:
Princeton Hydro also assessed other pollutant sources, including groundwater seepage, streambank erosion, and contributions from residential septic systems. Additionally, the impact of waterfowl, particularly Canada Goose, was evaluated using nutrient loading coefficients. The presence of these birds significantly contributes to phosphorus and nitrogen levels.
The hydrologic budget, representing the water balance of the lake, was calculated by considering inputs such as direct precipitation, overland runoff, tributary inflow, and groundwater seepage. This data is vital for conducting trophic state analyses and determining the feasibility of various in-lake restoration techniques. Internal loading of phosphorus, which occurs when anoxic conditions in the lake's bottom sediments release bound phosphorus into the water, was also analyzed.
Results of the analysis revealed that Mercer Lake, covering 287.1 acres, is influenced by a watershed area of 20,551.4 acres, predominantly consisting of cropland and forested areas. The lake's shallow nature coupled with significant sediment deposition in the eastern portion, underscores the importance of managing both external and internal nutrient loads.
Understanding the hydrologic and pollutant dynamics through this detailed analysis allows for the development of a lake management plan that helps to prioritize management efforts, target the primary sources of pollution, and effectively address HABs.
Monitoring water quality is essential for understanding the existing chemistry of a lake, identifying trends, pinpointing problems, and assessing nutrient levels. It provides critical data that informs management decisions and helps maintain the health and stability of aquatic ecosystems.
For Mercer Lake, Princeton Hydro conducted thorough water quality monitoring from 2021 to 2023. This involved analyzing in-situ, discrete, and plankton data collected over three growing seasons. The monitoring focused on various parameters, including hypolimnetic anoxia and associated phosphorus dynamics, which are key contributors to HABs. The data collected offered a current assessment of the lake’s trophic state and plankton community, providing a baseline to document shifts in water quality in response to future management measures.
The Princeton Hydro team performed 13 sampling events at two consistent stations in Mercer Lake: a deep water station near the dam (ML-1) and a mid-lake station (ML-2). Various parameters were monitored, including water temperature, dissolved oxygen (DO), pH, specific conductivity, chlorophyll a, and phycocyanin, using an In-Situ AquaTROLL 500 meter.
Water samples were collected at both in-lake stations at the surface (0.5 meters) and near the bottom (0.5 meters above the sediment) using a Van Dorn water sampler. Samples were preserved appropriately and transported to the NJDEP-certified laboratory Environmental Compliance Monitoring (ECM) for analysis. The samples were analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), total dissolved phosphorus (TDP), nitrate-N, nitrite-N, ammonia-N, total suspended solids (TSS), and turbidity. Surface samples were also analyzed for alkalinity, chloride, and hardness.
Additionally, samples were collected for zooplankton and phytoplankton analysis, including species composition, dominant organisms, and relative density. Cyanobacteria (blue-green algae) genera were quantified to estimate cell counts, providing an approximate concentration of cyanobacteria cells per milliliter of water. Samples were also analyzed for the cyanotoxin microcystins using the Abraxis field testing methodology.
The team also evaluated local climatic conditions during the 2021 - 2023 seasons compared to the long-term average. These conditions, including temperature and precipitation, can have significant effects on water quality. The combination of increased precipitation and an increase in temperatures sets the stage for HABs proliferation. The charts below the monthly mean temperatures and monthly precipitation from 2021 – 2023 and the 30-year average; ‘normal’ refers to the monthly average over the 30-year period from 1991 – 2020.
The Water Quality Monitoring analysis revealed several key insights about Mercer Lake's water quality, and indicated that cropland runoff was the most significant source of phosphorus, a key driver of HABs. Hypolimnetic anoxia (the bottom layer of the lake becomes devoid of oxygen) was observed during all three field sampling seasons, contributing to internal phosphorus loading. The water quality monitoring also provided valuable information on the lake’s trophic state and plankton community.
Trophic State Modeling is a method used to assess the productivity of a lake by measuring the levels of nutrients, such as phosphorus, and the resulting biological activity. This assessment helps determine the lake's overall health and informs management strategies. The Trophic State Index (TSI) is a common tool used in this process, calculating index values based on phosphorus concentrations, chlorophyll a levels, and Secchi depths.
For MCPC, Princeton Hydro, utilizing data collected in the field and through lake and watershed modeling, estimated the nutrient status and biological activity of Mercer Lake. Here are a few examples of the models the team utilized:
By leveraging these sophisticated models, Princeton Hydro was able to gain a detailed understanding of Mercer Lake's nutrient dynamics and productivity. Many models were run twice: once for the watershed-based phosphorus load and once for the total combined load. This allowed for a comprehensive assessment of both external and internal nutrient contributions.
To mitigate pollutant loading issues, the Lake and Watershed Management plan outlines a series of Best Management Practices (BMPs) recommendations for implementation throughout the watershed, which include bioretention systems, wetland buffers, riparian buffers, and lakefront aquascaping. Such measures are designed to reduce nutrient loads, improve water quality, and enhance the overall ecological health of the lake and its watershed. By addressing the root causes of nutrient loading and implementing targeted management strategies, the MCPC is continuing their commitment to providing a sustainable and enjoyable recreational experience for park users while safeguarding the lake's ecological integrity.
Stay tuned for more updates as we continue to work with the MCPC on implementing the Mercer Lake and Watershed Management Plan, ensuring the watershed remains a vibrant and healthy resource for generations to come.
Regional watershed planning is crucial for maintaining the health and sustainability of interconnected waterbodies. By considering entire watersheds rather than individual lakes, we can develop more effective and comprehensive strategies to manage water quality, control pollution, and enhance ecological resilience. This holistic approach ensures that all elements within the watershed are addressed, leading to more long-lasting improvements.
Princeton Hydro’s efforts in developing and implementing management plans for Mercer Lake, Curlis Lake, Rosedale Lake, and Spring Lake demonstrate the power of coordinated, science-based planning. By leveraging detailed data and advanced modeling techniques, our team is able to create tailored solutions that meet the specific needs of each lake while contributing to the overall health of the region's aquatic ecosystems.
To read about another project we’re working on in Mercer County, check out our blog about Miry Run Dam Site 21. Through a blend of engineering and ecological enhancements, we are working with MCPC to revitalize 279 acres. With each phase, we edge closer to a vibrant, inclusive space that harmonizes nature and community.
As we reflect on the winter of 2023-2024, it's evident that New Jersey experienced another unusually mild season, mirroring the winter of 2022-2023. Notably, Lake Hopatcong, located in Sussex and Morris Counties, remained virtually ice-free throughout the winter, with only a brief period of minor ice formation in early January. This pattern was not isolated to Lake Hopatcong; many lakes across the state and the broader Mid-Atlantic region exhibited similar ice-free conditions. Such conditions can lead to increased algal and plant growth earlier in the year.
Adding to this, from January to early June 2024, 15 of New Jersey's 21 counties recorded precipitation levels 26% to 50% higher than their long-term averages. The remaining six counties, predominantly in the southern part of the state, had precipitation increases of 11% to 25% above their long-term normals. This heightened precipitation is significant as it can transport nutrients, most notably phosphorus and nitrogen, into water bodies, potentially fueling the growth of algae.
Compounding these factors, long-range climate models and trends suggest that the summer of 2024 could rank among the hottest on record. The combination of a mild winter, increased precipitation, and anticipated high summer temperatures sets the stage for conditions similar to those experienced in 2019, a year marked by widespread harmful algal blooms (HABs) in numerous lakes.
HABs, characterized by rapid overgrowths of cyanobacteria, present serious challenges to water quality and aquatic ecosystems. Cyanobacteria, or blue-green algae, naturally occur in aquatic environments but can proliferate rapidly under warm, nutrient-rich conditions. These blooms pose risks to human health, wildlife, aquatic species, local economies, and the overall ecological balance. The interplay between climate change and HABs is undeniable: rising temperatures and altered precipitation patterns foster conditions that exacerbate bloom occurrences.
Given these circumstances, it is crucial for lake managers and water utilities to adopt proactive measures. Early and consistent sampling efforts can detect cyanobacteria and akinetes, dormant spores that contribute to bloom formation. Additionally, reducing nutrient inputs, particularly phosphorus, into waterways is essential to prevent HABs. Princeton Hydro strongly recommends that lake managers, water utilities, and concerned community members closely monitor their lakes, reservoirs, and riverways to stay as proactive as possible in managing these valuable resources.
By raising awareness, fostering collaboration, and implementing effective strategies, we can work towards safeguarding the health and sustainability of our freshwater ecosystems. Together, we can address the challenges posed by HABs and protect the integrity of our water bodies. For more information about HABs, click here.
Dr. Fred Lubnow, Princeton Hydro’s Senior Technical Director, Ecological Services, is an expert in aquatic and watershed management, restoration ecology, community and ecosystem ecology, and the use of benthic macroinvertebrate and fish in-stream bioassessment protocols. Dr. Lubnow has managed hundreds of lake projects and provides technical expertise for a variety of lake and watershed restoration projects.
His experience in lake and reservoir restoration includes the design and implementation of dredging, aeration, chemical control of nuisance species, nutrient inactivation (i.e. alum) and biomanipulation. His experience in watershed restoration includes the design and implementation of structural Best Management Practices (BMPs), the development of Total Maximum Daily Load (TMDL) pollutant budgets, and the design, implementation and analysis of watershed-based monitoring programs.
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!
New Jersey’s water-related infrastructure is a complex system, constantly facing the challenges posed by stormwater runoff and working to properly manage it. Stormwater management isn’t just about handling rainfall; it’s a critical aspect of preserving water quality and mitigating flooding risks. In New Jersey, where urbanization and rainfall patterns intersect, managing stormwater is more than just a priority; it’s a necessity. Enter a stormwater utility— a dedicated fee to address these stormwater management challenges.
New Jersey’s stormwater infrastructure (storm drains, sewer piping, etc.) is aging and unable to effectively handle the amount of runoff that has been flowing through the region in recent years. This is causing increased nutrient runoff and flooding in communities throughout the state. With increasing global temperatures and the proliferation of intense storm systems, this trend is likely to continue.
To address these issues, in 2019, New Jersey enacted the Clean Stormwater & Flood Reduction Law that allows municipalities, counties, groups of municipalities, and sewage and improvement authorities to establish a stormwater utility.
For many local leaders, the process to establish a utility can be complex, often depending on a number of details like the scope of the work and size of the community. In 2021, Princeton Hydro teamed up with the New Jersey League of Conservation Voters, New Jersey Future, and Flood Defense New Jersey to host a webinar explaining the purpose of a stormwater utility; how a stormwater utility works; how to decide if a stormwater utility is the right fit for a particular community; and how municipalities or counties can implement one.
In 2022, New Jersey Department of Environmental Protection (NJDEP) announced the availability of Technical Assistance for Stormwater Utility Feasibility Studies, which supports municipalities in completing a stormwater utility feasibility study. Stormwater feasibility studies can help communities weigh the costs and benefits of having a stormwater utility to determine if it's right for them. Princeton Hydro is currently conducting a feasibility study for the City of Lambertville.
Jersey Water Works is a collaborative effort of many diverse organizations and individuals who embrace the common purpose of transforming New Jersey’s water infrastructure. They bring people together to find equitable solutions focused on: Clean water and waterways; healthier, safer neighborhoods; local jobs; flood and climate resilience; and economic growth. Jersey Water Works consists of many different committees run by volunteers, including the Stormwater Utilities Subcommittee, which is part of the Asset Management and Finance Committee.
The Jersey Waterworks Stormwater Utility Subcommittee launched the “Stormwater Utility Informational Forum” comprising five one-hour-long, town-hall-style education sessions. Each session featured expert panelists who explored various aspects of creating a stormwater utility and establishing a sustainable and dedicated funding mechanism to pay for a community’s stormwater management program.
Utility leaders, government stormwater managers, municipal and county representatives, elected officials, experts and stakeholders came together to discuss the topics of stormwater financial planning and funding options; New Jersey legislation and the utility development process; stormwater rate structures and credits; stormwater utility policies; and stakeholder engagement.
Key leaders in the Stormwater Utility subcommittee who organized the information forum include Dana Patterson Grear, Director of Marketing and Communications for Princeton Hydro (co-chair); Micah Shapiro of RES (co-chair); Prabha Kumar of Black & Veatch Management Consulting LLC; and Elizabeth Treadway of WSP. The forum presenters included Prabha Kumar, Elizabeth Treadway, Dana Patterson Grear, Dave Mason of CDM Smith; Lindsey Sigmund of New Jersey Future.
Prabha Kumar and Dana Patterson Grear led the final session of the forum, which was dedicated to Stakeholder Engagement. They shared their expert recommendations and real-world experience in fostering community involvement, navigating the complexities of stakeholder engagement, and developing inclusive public meetings and dialogues related to implementing a stormwater utility feasibility study.
The presentation emphasized the significance of prioritizing stakeholder engagement early on and maintaining consistent engagement throughout the entire stormwater utility feasibility process. Prabha and Dana also provided tons of easy-to-follow, actionable tips, including:
How to structure your stakeholder groups, including the creation of a project team, a project champion and internal steering committee;
Which local community groups, municipal entities, and other external stakeholders to include in the conversation and when to include them;
Key factors in planning public workshops, like how many workshops to host, should the workshops be virtual or in-person, and how to structure the agenda for the best results; and
How to create engaging graphics, solicit feedback and educate the target audience in ways that are inclusive, informative and tailored to the unique characteristics of the community.
"Creating a stormwater utility in your community can be challenging as it is a public policymaking process. Engaging stakeholders throughout the entire process and educating the public is not just a step; it's the cornerstone to success," said Dana. "It's about embracing a diversity of voices from day one, listening to concerns and ideas, and collaboratively shaping a solution that resonates with your communities' needs."
Watch the full presentation.
The Stormwater Utility Information Forum served as a platform for sharing expertise and fostering dialogue around supporting community efforts to properly manage stormwater and protect water quality. As the conversation continues, it's crucial to leverage these insights to drive meaningful change in stormwater management initiatives across New Jersey.
The sessions were held via Zoom and the recordings of the forum sessions made available on the Jersey Water Works website. The recorded sessions serve as invaluable resources for individuals, communities, and policymakers interested in delving deeper into stormwater management.
The journey towards sustainable stormwater management is ongoing. If you or your community are interested in furthering this cause or exploring a stormwater utility, don't hesitate to reach out. The Jersey Water Works Stormwater Utility Subcommittee and Princeton Hydro welcome all voices committed to creating a more resilient and equitable water infrastructure. For more information about the Stormwater Utility Subcommittee or to get involved, please contact info@jerseywaterworks.org. Also, please explore New Jersey Future's New Jersey Stormwater Utility Resource Center which is a treasure trove of resources on this topic!
Princeton Hydro is a leader in innovative, cost-effective, and environmentally sound stormwater management systems. The preparation of stormwater management plans and design of stormwater management systems for pollutant reduction is an integral part of our projects - learn more.
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