The Lake Hopatcong Commission, in partnership with Roxbury Township and Princeton Hydro, and with support from the Lake Hopatcong Foundation, has been awarded a $367,000 Water Quality Restoration Grant from the New Jersey Department of Environmental Protection (NJDEP) for the Lake Hopatcong Watershed Basin Enhancement Project.

The project will retrofit an existing stormwater detention basin with a series of green stormwater infrastructure improvements designed to slow, capture, and naturally treat stormwater runoff. The basin project, located between King Road and Mount Arlington Boulevard in Roxbury Township, was identified in the 2021 Upper Musconetcong River Implementation Plan (WIP) as a priority project to reduce non-point source pollution and improve water quality before stormwater enters the lake at King Cove.

"Roxbury is truly thankful for the Lake Hopatcong Commission. Lake Hopatcong is such a valuable resource and the commission’s work alongside Princeton Hydro has preserved a natural treasure," said Shawn Potillo, Mayor of Roxbury. "We are grateful to the NJDEP for their support and award of this grant. This water basin project in Roxbury will help continue the commission’s purpose of keeping the lake a beautiful place to swim, boat, relax, and call home."

A range of improvements will be incorporated including planting native vegetation and managing invasive species to stabilize soils, support wildlife, and naturally filter pollutants before they reach the lake. Erosion and sediment control measures will further protect the area by reducing stormwater scouring and preventing bank degradation.

In addition to on-the-ground restoration, the project emphasizes public education and outreach to promote best management practices and ongoing watershed stewardship among residents and local partners. Project success will be evaluated through water quality monitoring conducted before and after construction, providing measurable data on the project’s effectiveness in improving water quality.

“Lake Hopatcong’s fight against harmful algal blooms requires a united front, where many projects, like retrofitting stormwater basins to capture nutrients before they go into the lake, collectively make a big impact,” said Dr. Fred Lubnow, Senior Technical Director of Ecological Services at Princeton Hydro. “Thanks to the leadership of the Lake Hopatcong Commission and the Lake Hopatcong Foundation, this collaborative approach is driving real progress toward cleaner water, healthier ecosystems, and a more resilient future for New Jersey’s largest lake.”

The basin enhancement project is funded through NJDEP’s Water Quality Restoration Grant Program, which is supported by the U.S. Environmental Protection Agency under Clean Water Act Section 319(h). Along with the state grant, the project includes a $200,000 local match from the Commission, Roxbury Township, and the Lake Hopatcong Foundation, and builds on a $98,000 planning grant awarded by the New Jersey Highlands Council in 2024 that helped prepare the project for implementation and future grant opportunities.

“This project represents an important step forward in improving Lake Hopatcong’s water quality and reducing pollutants that contribute to harmful algal blooms,” said Ron Smith, Chairman of the Lake Hopatcong Commission. “We’re grateful to NJDEP, Roxbury Township, Princeton Hydro, the Foundation and the Highlands Council for their continued partnership in protecting this vital resource.”

[caption id="attachment_18637" align="aligncenter" width="1380"]

Photo by the Lake Hopatcong Commission[/caption]

The Lake Hopatcong Commission is an independent state agency created in, but not of, the New Jersey Department of Environmental Protection. LHC is recognized as a steward of the lake and watershed. The 11-member Board of State and local appointees include representatives of the four municipalities and two counties surrounding Lake Hopatcong. LHC is responsible for fulfilling the obligations of the Lake Hopatcong Protection Act, to safeguard Lake Hopatcong as a natural, scenic, and recreational resource. To learn more, click here to visit lakehopatcongcommission.org.

For over 30 years, Princeton Hydro has been proud to work alongside the Lake Hopatcong Commission and Lake Hopatcong Foundation in support of the lake’s health and resilience. Through these partnerships, and with the support of numerous funding agencies, a wide range of projects have been implemented to reduce pollutant loads, manage stormwater runoff, address invasive species and harmful algal blooms, and enhance habitat quality—helping to protect both the lake and the communities that depend on it. To learn more about our collaborative efforts, click here.

The Borough of Mountain Lakes has received grant funding from the New Jersey Highlands Council to develop a comprehensive Lake and Watershed Management Plan for nine lakes within the Borough. To lead this effort, the Borough engaged Princeton Hydro, a leader in ecological and engineering consulting. The initiative will focus on characterizing hydrologic and nutrient dynamics within the Borough’s lake systems and watersheds to guide targeted water quality improvement and management strategies.

“Mountain Lakes takes great pride in our lakes, which play an important role in defining our community. Through our partnership with the Highlands Council and Princeton Hydro, we’re taking a proactive, data-driven approach to protecting both the environmental and recreational value of our lakes and waterways, with the goal of preserving these vital natural resources for generations to come,” said Borough of Mountain Lakes Manager Mitchell Stern.

A selection process was undertaken by the Borough of Mountain Lakes, Princeton Hydro, and the New Jersey Highlands Council to define the scope of this Lake and Watershed Management Program. In accordance with Policy 1L2 and Objective 1L2a of the NJHC Regional Master Plan, which establish lake management tiers and prioritize lakes greater than 10 acres for protection and management, nine lakes were selected for the study: Birchwood Lake, Crystal Lake, Wildwood Lake, Sunset Lake, Mountain Lake, Shadow Pond, Olive Pond, Grundens Pond, and Cove Pond. These lakes represent the waterbodies in the Borough and were chosen to ensure the program focuses on areas with the greatest potential impact on water quality, watershed function, and community value.

Princeton Hydro’s work will include watershed modeling, hydrologic and pollutant load analyses, and in-lake and watershed-based water quality monitoring. Once the data is analyzed, Princeton Hydro will develop a General Assessment Report that identifies the primary drivers of eutrophication and outlines a prioritized set of management strategies to effectively reduce nutrient loading and enhance long-term lake health.

“The regional, science-based approach to lake and watershed management has proven to be a powerful tool for municipalities in the Highlands Region,” said Christopher Mikolajczyk, CLM, Senior Manager of Aquatics at Princeton Hydro, Certified Lake Manager, and lead designer for this initiative. “We’re excited to collaborate with Mountain Lakes to help identify cost-effective, data-driven strategies that will enhance water quality throughout the watershed and help safeguard these treasured natural resources.”

The New Jersey Highlands Water Protection and Planning Council (Highlands Council) is a regional planning agency that partners with municipalities and counties in the Highlands Region to promote proactive watershed protection. Established under the New Jersey Highlands Water Protection and Planning Act of 2004, the Council has funded numerous water-quality-related planning initiatives.

Historically, municipalities and private lake associations have managed water quality issues independently. However, taking a coordinated, watershed-based approach enables communities to more effectively address pollution sources, improve water quality, and prevent the spread of invasive species and harmful algal blooms.

Mountain Lakes joins several other Highlands region municipalities that have received Highlands council funding to implement similar lake and watershed management initiatives. In 2019, the Borough of Ringwood became the first municipality in New Jerey to adopt a regional, public-private approach to lake management, partnering with four lake associations across six lakes. Since the completion of the Ringwood plan, NJDEP has funded recommendations from the plan. This model has since inspired additional projects, including watershed assessments for West Milford Township, Rockaway Township, Byram Township, Vernon Township, and Somerset County Parks Commission. Princeton Hydro worked with each agency to develop the respective scope of work to secure grant funding from the Highlands Council.

Photo from the Borough of Mountain Lakes. [post_title] => Borough of Mountain Lakes Launches Lake and Watershed Management Program with Funding from NJ Highlands Council [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => borough-of-mountain-lakes-launches-lake-and-watershed-management-program-with-funding-from-the-new-jersey-highlands-council [to_ping] => [pinged] => [post_modified] => 2025-11-11 17:38:59 [post_modified_gmt] => 2025-11-11 17:38:59 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18685 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [2] => WP_Post Object ( [ID] => 18586 [post_author] => 1 [post_date] => 2025-11-06 00:15:54 [post_date_gmt] => 2025-11-06 00:15:54 [post_content] =>

The New Jersey Department of Environmental Protection (NJDEP) recently announced $8 million in Water Quality Restoration Grants to support projects that reduce nonpoint source pollution, mitigate harmful algal blooms, restore riparian areas, and enhance watershed and climate resilience. Funded through Section 319(h) of the federal Clean Water Act and administered by the DEP's Watershed and Land Management Program, these grants were awarded to municipalities, nonprofit organizations, and academic institutions across the state.

Princeton Hydro is proud to be a partner on five of the 17 funded projects. Our contributions vary by project and encompass activities such as engineering design, water quality assessment, watershed-based planning, and technical support for implementing stormwater and habitat restoration measures. Let's take a deeper look at these collaborative efforts:

1. The Watershed Institute – Watershed-Based Planning for Assunpink Creek

The Watershed Institute received $205K in 319(h) grant funding to develop a watershed-based plan for the Assunpink Creek watershed, located within the Raritan River Basin. This watershed spans 11 municipalities across two counties, where varied landscapes and demographics share common challenges such as localized flooding, stormwater management, and water quality degradation, highlighting the need for a coordinated, watershed-wide, science-driven approach.

The plan will evaluate pollution sources and identify large-scale restoration opportunities, including green infrastructure and riparian buffer restoration, to improve water quality and reduce flooding. It will also assess the cost, feasibility, and pollutant reduction potential of proposed measures to ensure practical implementation. Princeton Hydro supported the Institute in developing the grant proposal and planning framework, leveraging our expertise in watershed-based planning to prioritize nature-based solutions that address both water quality and climate resilience. This initiative represents a critical step toward regional collaboration, enabling upstream and downstream communities to work together on strategies that strengthen watershed health, protect public safety, and build long-term resilience.

2. Lake Hopatcong Commission – Watershed-Based Stormwater BMPs

The Lake Hopatcong Commission (LHC) was awarded $366K to retrofit an existing stormwater detention basin between King Road and Mount Arlington Boulevard in Roxbury Township. This retrofit is part of a larger Watershed Implementation Plan that Princeton Hydro developed in collaboration with LHC, which prioritizes nutrient reduction and stormwater management strategies across the Lake Hopatcong watershed. Over the past several years, LHC has actively implemented multiple elements of this plan to address harmful algal blooms (HABs) and improve water quality.

For this project, Princeton Hydro is providing engineering design and technical oversight to transform the existing basin into a green stormwater infrastructure system that slows, captures, and naturally treats runoff before it enters King Cove. The design incorporates native vegetation, invasive species management, and erosion control measures to stabilize soils and filter pollutants, reducing nutrient loading, which is one key driver of HABs. Public outreach and pre- and post-construction water quality monitoring will ensure performance tracking and measurable improvements. This basin retrofit represents a critical step in a coordinated, science-based approach to restoring ecological health and water quality in New Jersey’s largest lake.

3. Cozy Lake, Jefferson Township – Addressing Emerging Contaminants

Jefferson Township received $350K in grant funding to develop an Emerging Contaminants Management Plan for Cozy Lake, focusing on cyanotoxins and HABs. Cozy Lake is a 28-acre waterbody within a 1,152-acre sub-watershed that includes both forested (60%) and developed (29%) land. The lake is fed by the Rockaway River at its northern end and a smaller southeastern inlet, with outflow through a dam on the western edge.

The shoreline is primarily residential lawn with minimal emergent wetlands, and several inlets and rock-lined drainage ditches exhibit erosion and lack slope protection, contributing to sediment loading. Princeton Hydro provided early technical input to shape this innovative project with the creation of a comprehensive Jefferson Township Lake and Watershed Restoration and Protection Plan. As part of the plan, Princeton Hydro made recommendations for Cozy Lake, which included enhancing shoreline buffers with native vegetation and installing living shorelines at select properties to stabilize soils, filter stormwater and reduce nutrient loading, improve habitat quality, and enhance community access. These measures, combined with in-lake monitoring and proactive management strategies, will help mitigate HABs and protect ecological and public health.

4. Rockaway Township – Watershed-Based Green Infrastructure

Rockaway Township received $399K in grant funding to implement elements of its Watershed Implementation Plan, focusing on green infrastructure stormwater management and nutrient reduction to improve water quality. The project will retrofit the municipal complex by converting a rock-lined drainage swale into a vegetated swale with a bioretention basin, designed to filter stormwater runoff and reduce nonpoint source pollutants entering Fox’s Pond and Fox Brook.

Princeton Hydro played a key role in developing the Watershed Implementation Plan, which encompasses 11 private lakes within the Rockaway River watershed, prioritizing critical locations for intervention and designing cost-effective green infrastructure BMPs. This regional approach aligns with strategies recommended by NJDEP and the Highlands Council. The plan included a comprehensive watershed-based assessment to identify and quantify factors contributing to eutrophication, evaluate management measures, estimate costs, and establish an implementation schedule. Princeton Hydro authored the final report, which guided the Township in applying for the Section 319(h) grant and now informs the design and construction of green stormwater infrastructure that will deliver measurable water quality improvements while supporting ecological restoration goals.

5. Green Trust Alliance – Green Infrastructure and Community Engagement

Green Trust Alliance (GTA), a nationally accredited land trust and public charity dedicated to accelerating large-scale conservation, received $1.39 million in NJDEP funding to implement green infrastructure improvements at Pinelands Regional High School in Tuckerton, New Jersey. This initiative targets the Tuckerton Creek watershed, which drains into Tuckerton Creek and ultimately flows into Barnegat Bay—a critical estuary spanning 33 municipalities in Ocean County and four in Monmouth County. The retrofit will transform the school’s stormwater detention basin into a multi-functional system that mimics natural hydrology, enhances flow control, and improves water quality locally and in the larger Barnegat Bay watershed.

Working with GTA and GreenVest, Princeton Hydro is serving as the design engineer, applying nature-based engineering and ecological restoration techniques to intercept, evapotranspire, and infiltrate stormwater runoff at its source. In addition to its technical objectives, the effort includes a strong community engagement component and an educational platform for students. By bringing green infrastructure into the school environment, the initiative provides hands-on experience with water resources, stormwater management, and ecological engineering, help to build STEM skills while fostering a deeper connection to the surrounding landscape and an understanding of how natural systems work together to support environmental and community health.

Princeton Hydro also assisted several of these partners in developing successful NJDEP Section 319(h) grant applications, providing technical documentation, conceptual designs, and pollutant load reduction estimates to strengthen the proposals.

To date, the Murphy Administration has awarded more than $33M in Water Quality Restoration grants to improve the health of waterways in all corners of the state. Click here to read about all the 2025 grant funding recipients and their innovative projects.

As NJDEP Environmental Protection Commissioner Shawn M. LaTourette noted in the department's press release, “Enhancing the ecological health of our lakes, rivers, streams and coastal waters has long been a priority of the Murphy Administration. The Department of Environmental Protection is pleased to award these grants that will help our partners advance a variety of strategies to improve the health of these waterways and enhance the quality of life in our communities.”

We are proud to play a continued role in advancing that mission: helping communities implement practical, data-driven solutions that make a measurable difference for New Jersey’s waterways and the people who depend on them. Click here to learn more about our work to protect natural habitat and restore water quality throughout the New Jersey.

[post_title] => NJDEP Awards $8M for Water Quality Restoration Projects [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => njdep-319h-grants-2025 [to_ping] => [pinged] => [post_modified] => 2025-11-07 01:20:58 [post_modified_gmt] => 2025-11-07 01:20:58 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18586 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 18009 [post_author] => 1 [post_date] => 2025-08-07 19:26:22 [post_date_gmt] => 2025-08-07 19:26:22 [post_content] =>

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.

Inside the Guide

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 equips readers with:

A foundational understanding of how to plan and apply NBS in a variety of settings, from urban spaces to coastal habitats to inland farmland.
An introduction to cost-benefit analysis, including the basics of benefit transfer methodology and its role in justifying funding proposals.
A comprehensive toolbox, including policy and permitting guidance, project examples, datasets, and funding and monitoring resources.
In-depth profiles of five NBS categories: Bioretention Systems, Coastal Habitats, Regenerative Land Management, Stream Restoration, and Urban Forestry. Each category includes specific techniques like dam removal, living shorelines, and rain gardens.

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.

[gallery link="none" columns="2" size="large" ids="18015,18014"]

Sections at a Glance

The guide's easy-to-follow format includes four key sections:

Section 1: Setting the Stage - Introduces the purpose of the guide, its intended users, and how to easily navigate its contents.
Section 2: Planning for Nature-Based Solutions - Covers essential planning considerations, including selecting a planning horizon, aligning with local land use plans, permitting, funding, community engagement, equity, adaptive management, benefit-cost analysis, and climate change resilience.
Section 3: Nature-Based Solutions Profiles - Provides a detailed look at NBS strategies, including their intended uses, implementation techniques, primary benefits and co-benefits, and the specific environmental hazards they help address (i.e., sea level rise, wildfire, inland flooding, etc.)
Section 4: Appendix - Includes a project planning checklist, case studies, a glossary, references, and links to helpful resources, tools, and data.

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.

Webinars and outreach events are currently being planned as part of a broader effort to build awareness and support the guide's use. Stay tuned for future announcements. To learn more about the Rutgers University New Jersey Climate Change Resource Center, click here. [post_title] => New Resource: A Comprehensive Guide to Nature-Based Solutions in New Jersey [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => guide-to-nature-based-solutions-in-new-jersey [to_ping] => [pinged] => [post_modified] => 2025-08-07 19:28:46 [post_modified_gmt] => 2025-08-07 19:28:46 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18009 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [4] => 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:

Permeable parking lot with 10 spaces, including one van-accessible ADA parking spot
10-foot-wide recreational trail that connects key features throughout the site
A small gathering space along the trail
2500-square-foot elevated stone overlook, with seating

[gallery link="none" columns="2" ids="17880,17941,17878,17963"]

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.

The photos below show the geoweb material being installed along the trail: [gallery link="none" ids="17958,17957,17956"]

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.

[gallery link="none" columns="2" ids="17961,17877,17874,17935"]

Plan Your Visit

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.

[post_title] => A New Gateway to the Meadowlands: Steven R. Rothman Overlook and Preserve [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => a-new-gateway-to-the-meadowlands-steven-r-rothman-overlook-and-preserve [to_ping] => [pinged] => [post_modified] => 2025-07-22 21:39:22 [post_modified_gmt] => 2025-07-22 21:39:22 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=17931 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [5] => WP_Post Object ( [ID] => 17748 [post_author] => 1 [post_date] => 2025-07-08 09:52:44 [post_date_gmt] => 2025-07-08 09:52:44 [post_content] =>

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.

[gallery link="none" columns="4" size="medium" ids="17787,17788,7339,17789"]

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.

Understanding the Impacts of Invasive Species

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:

Competition for Resources: Invasives often outcompete native species for food, light, and habitat.
Direct Harm: Some invasives prey on or parasitize native species.
Disease Transmission: Non-native organisms can introduce new diseases or parasites to ecosystems.
Loss of Biodiversity: Invasives frequently crowd out or eliminate native species, resulting in monocultures—ecosystems dominated by a single species.

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.

Why Control Matters: Ecological, Economic, and Regulatory Incentives

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.

Control efforts are also driven by:

Ecological Benefits: Removing invasive species makes space for native vegetation to regenerate and flourish.
Economic Considerations: Invasives can harm agriculture, tourism, and recreation. Control measures help minimize these financial impacts.
Regulatory Compliance and State-Level Incentives: Wetland managers, landowners, and developers are increasingly required to control invasives to comply with state/federal environmental regulations aimed at tracking, managing, and reducing the spread of harmful invasives across ecosystems.
Land Use Goals: In restoration projects, removing invasives is often the first step in reestablishing natural hydrology, enhancing habitat, and increasing accessibility.

From early detection and rapid response to long-term monitoring and management, invasive species control requires collaboration, planning, and the right set of tools.

Invasive Species Control Methods

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.

[gallery size="large" link="none" ids="17780,17779,17805"]

By using the Marsh Master®, we’re able to:

Control invasive and non-native vegetation efficiently and effectively
Minimize impact on ecosystems
Prepare sites for seeding and planting native species
Access hard-to-reach wetland, bog, marshland and other delicate habitats

Take a look at the Marsh Master® in the field, tackling Phragmites in tough terrain:

[embed]https://youtu.be/lMkkD-WFz3E[/embed]

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.

[gallery link="none" columns="2" size="medium" ids="13019,13022"]

Case Studies: Invasive Species Mitigation in Action

GreenVest Baltimore: Phragmites Control & Tidal Marsh Restoration

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.

[embed]https://youtu.be/R3x7vb0EHKk[/embed]

Mercer County: Long-Term Invasive Species Management

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.

[gallery columns="1" link="none" size="medium" ids="17756,17755"]

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.

Lower Raritan Mitigation Site: Multi-Year, Multi-Faceted Wetland Restoration

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.

South Cape May Meadows Nature Preserve: Restoring Balance & Enhancing Access

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.

[gallery link="none" columns="2" size="medium" ids="17772,17771"]

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.

Stormwater Basin Maintenance & MS4 Compliance: Managing Invasives & Non-Natives

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.

Protecting the Future of Our Wetlands and Wildlife

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.

[post_title] => Invasive Species in Focus: Impacts, Solutions, and Restoration Successes [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => invasive-species-in-focus-impacts-solutions-and-restoration-successes [to_ping] => [pinged] => [post_modified] => 2025-11-07 19:48:23 [post_modified_gmt] => 2025-11-07 19:48:23 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=17748 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [6] => WP_Post Object ( [ID] => 17695 [post_author] => 1 [post_date] => 2025-06-28 00:29:22 [post_date_gmt] => 2025-06-28 00:29:22 [post_content] =>

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.

Historical Management of Harveys Lake

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.

[caption id="attachment_12423" align="aligncenter" width="896"]

Harveys Lake, Luzerne County, PA in February 2023 (photo by Jason Miller)[/caption]

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. Volunteers install native plants in one of the FWIs installed in Harveys Lake. Photo by: Mark Moran, The Citizen’s Voice.

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.

Innovative Solutions for Stormwater Nutrient Reduction

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.

Measuring Success: Sampling, Monitoring, & Key Findings

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.

Monitoring Set-Up

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.

Data Analysis & Pollutant Load Modeling

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:

Total Nitrogen (TN),
Total Phosphorus (TP),
Total Suspended Solids (TSS), and
Soluble Reactive Phosphorus (SRP).

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.

Key Findings

Overall, the study revealed variable but promising results across media types and installation locations:

SRP: Reductions were more pronounced in the EutroSORB® dataset, with 50-83% of NSBB samples and 67% of stream samples showing improvement. Biochar performed well in stream applications, achieving SRP reductions in 83% of samples, and moderately in NSBBs, with 33-67% showing positive results.
TN: Reductions were most evident in EutroSORB®-treated NSBBs, with 67-100% of samples showing a net decrease in concentrations.
TP: Removal was most effective in NSBBs utilizing EutroSORB®, where 67% of samples showed a net reduction, with values ranging from -14% to -70%. Biochar-treated NSBBs demonstrated more modest results, with 33-50% of samples showing TP reductions.

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.

Engaging the Community & Enriching the Landscape

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.

[gallery link="none" ids="17609,17612,17608"]

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.

Click here to learn more about and explore the StoryMap.

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.

A Scalable, Shareable Solution

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.

[post_title] => A Local Solution with Regional Reach: Stormwater Nutrient Reduction at Harveys Lake [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => a-local-solution-with-regional-reach-stormwater-nutrient-reduction-at-harveys-lake [to_ping] => [pinged] => [post_modified] => 2025-11-07 19:47:09 [post_modified_gmt] => 2025-11-07 19:47:09 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=17695 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [7] => WP_Post Object ( [ID] => 17677 [post_author] => 1 [post_date] => 2025-06-18 12:59:00 [post_date_gmt] => 2025-06-18 12:59:00 [post_content] =>

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.

What You’ll Discover Inside the StoryMap

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:

A pictorial, historical timeline of water quality management at Harveys Lake;
An interactive Restoration Progress Map with clickable project sites;
Notable milestones in reducing nutrient pollution and managing stormwater; and
Restoration project highlights, complete with historical maps, illustrations, and photos

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.

Click here to explore the StoryMap now!

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.

[post_title] => NEW Interactive ArcGIS StoryMap Showcases Harveys Lake’s Legacy of Water Quality Leadership [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => new-interactive-arcgis-storymap-showcases-harveys-lakes-legacy-of-water-quality-leadership [to_ping] => [pinged] => [post_modified] => 2025-07-14 15:51:12 [post_modified_gmt] => 2025-07-14 15:51:12 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=17677 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [8] => WP_Post Object ( [ID] => 15800 [post_author] => 1 [post_date] => 2024-12-04 14:59:57 [post_date_gmt] => 2024-12-04 14:59:57 [post_content] =>

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.

What Exactly is Daylighting?

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.

The Benefits of Daylighting Streams

Daylighting streams offers numerous advantages to both the environment and local communities. Some key benefits include:

Improved Water Quality: By restoring the natural flow of water, daylighted streams help filter pollutants and reduce nutrient loads, leading to healthier ecosystems.
Flood Mitigation: Daylighted streams can absorb stormwater more effectively, reducing the risk of urban flooding during heavy rain events.
Enhanced Biodiversity: Restoring stream habitats encourages the return of native plants and wildlife, boosting local biodiversity. The process can also lead to restored fish passage.
Public Health and Recreation: Exposure to natural environments improves mental and physical well-being, and daylighted streams create new spaces for recreation and community engagement.
Urban Revitalization: These projects can transform neglected areas into vibrant public spaces, improving property values and contributing to the overall quality of life.

Daylighting in Action: Project Highlights

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:

Petty's Run Stream Daylighting and Floodplain Creation in Trenton, NJ

[gallery link="none" size="medium" ids="15805,15806,15807"]

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 Zoo Stream Restoration

[gallery link="none" size="medium" ids="9410,9761,14291"]

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.

Expert Insights on Daylighting

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.

Click here to read more about Princeton Hydro's innovative stream restoration initiatives. [post_title] => Reviving Buried Waterways: The Benefits of Daylighting Streams [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => reviving-buried-waterways [to_ping] => [pinged] => [post_modified] => 2025-01-13 15:46:30 [post_modified_gmt] => 2025-01-13 15:46:30 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=15800 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [9] => WP_Post Object ( [ID] => 15760 [post_author] => 1 [post_date] => 2024-09-24 21:58:58 [post_date_gmt] => 2024-09-24 21:58:58 [post_content] =>

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.

Partnering for Progress: Princeton Hydro and the City of Lambertville

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.

[gallery columns="2" link="none" size="medium" ids="15769,15770"]

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.

A Model for Resilience and Stewardship

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:

[embed]https://youtu.be/0kwuBLSl8tE?si=_KkaeeMkLI7RNchH[/embed]

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."

[post_title] => City of Lambertville Honored with NJDEP Award for Stormwater Management Efforts [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => city-of-lambertville-honored-with-njdep-award-for-stormwater-management-efforts [to_ping] => [pinged] => [post_modified] => 2024-09-24 21:58:58 [post_modified_gmt] => 2024-09-24 21:58:58 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=15760 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [10] => WP_Post Object ( [ID] => 15503 [post_author] => 1 [post_date] => 2024-09-05 07:26:46 [post_date_gmt] => 2024-09-05 07:26:46 [post_content] =>

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.

Expanding the Initiative Across Mercer County

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.

These lakes are:

Curlis Lake in Curlis Lake Woods Park
Rosedale Lake in Rosedale Park
Spring Lake in John A. Roebling Memorial Park

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!

Historical Data Review: Laying the Foundation for Informed Management

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.

Bathymetric Survey: Mapping Mercer Lake's Depths and Sediments

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: Understanding the Sources and Impacts of Pollution

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.

Water Quality Monitoring: Ensuring a Healthy Ecosystem

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.

[gallery columns="2" size="medium" ids="15505,15506"]

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: Assessing Lake Productivity

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:

The Carlson’s Trophic State Index (TSI): This index assesses the trophic state of lakes by calculating index values based on phosphorus and chlorophyll a concentrations and Secchi depths that relate to each other on a similar scale. The higher these numbers are, the more representative they are of eutrophic conditions. Carlson’s trophic state index (TSI) was calculated for each in-lake sampling event using surface concentrations of TP, Chlorophyll a, and Secchi depths collected during water quality monitoring events throughout the season.
Kirchner and Dillon’s Phosphorus Retention: This metric utilizes the incoming hydraulic load from the watershed, as well as the total area of the waterbody, to estimate what percentage of incoming phosphorus will stay within the waterbody rather than be flushed from the system, providing insights into the lake's capacity to hold nutrients and its likelihood of eutrophic conditions.
Vollenweider Predicted Phosphorus: this model estimates phosphorus concentrations in a lake by considering incoming total phosphorus, hydraulic load, mean depth, and hydraulic residence time. This model helps assess the lake's nutrient status and its suitability for recreational use.

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.

The Importance of Regional Watershed Planning

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.

[post_title] => From Data to Action: Mercer County Watershed Management [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => from-data-to-action-mercer-county-watershed-management [to_ping] => [pinged] => [post_modified] => 2024-12-10 17:47:41 [post_modified_gmt] => 2024-12-10 17:47:41 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=15503 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) ) [post_count] => 11 [current_post] => -1 [before_loop] => 1 [in_the_loop] => [post] => WP_Post Object ( [ID] => 18636 [post_author] => 1 [post_date] => 2025-11-10 17:09:04 [post_date_gmt] => 2025-11-10 17:09:04 [post_content] =>

[caption id="attachment_18637" align="aligncenter" width="1380"]

Photo by the Lake Hopatcong Commission[/caption]

[post_title] => Lake Hopatcong Commission Awarded $367,000 NJDEP Grant for Water Quality Improvements in Roxbury Township [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => lake-hopatcong-commission-awarded-367000-njdep-grant-for-water-quality-improvements-in-roxbury-township [to_ping] => [pinged] => [post_modified] => 2025-11-10 17:09:04 [post_modified_gmt] => 2025-11-10 17:09:04 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18636 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [comment_count] => 0 [current_comment] => -1 [found_posts] => 92 [max_num_pages] => 9 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => [is_tag] => [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => 1 [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_favicon] => [is_posts_page] => 1 [is_post_type_archive] => [query_vars_hash:WP_Query:private] => 6b977d52b009ae9a47e40159560ea821 [query_vars_changed:WP_Query:private] => 1 [thumbnails_cached] => [allow_query_attachment_by_filename:protected] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) [query_cache_key:WP_Query:private] => wp_query:e1502d5e6da96a917e5749c5a6266349:0.25771600 17645451960.26197600 1764545196 )

Home

Blog

Posted on November 10, 2025 by Princeton Hydro

1. The Watershed Institute – Watershed-Based Planning for Assunpink Creek

2. Lake Hopatcong Commission – Watershed-Based Stormwater BMPs

3. Cozy Lake, Jefferson Township – Addressing Emerging Contaminants

4. Rockaway Township – Watershed-Based Green Infrastructure

5. Green Trust Alliance – Green Infrastructure and Community Engagement

Inside the Guide

Sections at a Glance

About Congressman Rothman

Designing a Sustainable, Inclusive Public Space

Plan Your Visit

Understanding the Impacts of Invasive Species

Why Control Matters: Ecological, Economic, and Regulatory Incentives

Invasive Species Control Methods

Case Studies: Invasive Species Mitigation in Action

GreenVest Baltimore: Phragmites Control & Tidal Marsh Restoration

Mercer County: Long-Term Invasive Species Management

Lower Raritan Mitigation Site: Multi-Year, Multi-Faceted Wetland Restoration

South Cape May Meadows Nature Preserve: Restoring Balance & Enhancing Access

Stormwater Basin Maintenance & MS4 Compliance: Managing Invasives & Non-Natives

Protecting the Future of Our Wetlands and Wildlife

Historical Management of Harveys Lake

Innovative Solutions for Stormwater Nutrient Reduction

Measuring Success: Sampling, Monitoring, & Key Findings

Monitoring Set-Up

Data Analysis & Pollutant Load Modeling

Key Findings

Engaging the Community & Enriching the Landscape

A Scalable, Shareable Solution

What You’ll Discover Inside the StoryMap

What Exactly is Daylighting?

The Benefits of Daylighting Streams

Daylighting in Action: Project Highlights

Petty's Run Stream Daylighting and Floodplain Creation in Trenton, NJ

Thompson Park Zoo Stream Restoration

Expert Insights on Daylighting

Partnering for Progress: Princeton Hydro and the City of Lambertville

A Model for Resilience and Stewardship

Expanding the Initiative Across Mercer County

Historical Data Review: Laying the Foundation for Informed Management

Bathymetric Survey: Mapping Mercer Lake's Depths and Sediments

Hydrologic and Pollutant Loading Analysis: Understanding the Sources and Impacts of Pollution

Water Quality Monitoring: Ensuring a Healthy Ecosystem

Trophic State Modeling: Assessing Lake Productivity

The Importance of Regional Watershed Planning

Blog

Popular Topics

Company News

Engineering

Environmental Action

Environmental Services

Flood Mitigation

Invasive Species Management

Lake and Pond Management

Natural Resource Management

Stormwater Management

Stream Restoration

get in touch

How would you like to be contacted?

Careers

Wrapper title

Wrapper title

Wrapper title

Wrapper title