search
WP_Query Object
(
    [query] => Array
        (
            [category_name] => lake-and-pond-management
        )

    [query_vars] => Array
        (
            [category_name] => lake-and-pond-management
            [error] => 
            [m] => 
            [p] => 0
            [post_parent] => 
            [subpost] => 
            [subpost_id] => 
            [attachment] => 
            [attachment_id] => 0
            [name] => 
            [pagename] => 
            [page_id] => 0
            [second] => 
            [minute] => 
            [hour] => 
            [day] => 0
            [monthnum] => 0
            [year] => 0
            [w] => 0
            [tag] => 
            [cat] => 37
            [tag_id] => 
            [author] => 
            [author_name] => 
            [feed] => 
            [tb] => 
            [paged] => 1
            [meta_key] => 
            [meta_value] => 
            [preview] => 
            [s] => 
            [sentence] => 
            [title] => 
            [fields] => all
            [menu_order] => 
            [embed] => 
            [category__in] => Array
                (
                    [0] => 34
                )

            [category__not_in] => Array
                (
                )

            [category__and] => Array
                (
                )

            [post__in] => Array
                (
                )

            [post__not_in] => Array
                (
                )

            [post_name__in] => Array
                (
                )

            [tag__in] => Array
                (
                )

            [tag__not_in] => Array
                (
                )

            [tag__and] => Array
                (
                )

            [tag_slug__in] => Array
                (
                )

            [tag_slug__and] => Array
                (
                )

            [post_parent__in] => Array
                (
                )

            [post_parent__not_in] => Array
                (
                )

            [author__in] => Array
                (
                )

            [author__not_in] => Array
                (
                )

            [search_columns] => Array
                (
                )

            [ignore_sticky_posts] => 
            [suppress_filters] => 
            [cache_results] => 1
            [update_post_term_cache] => 1
            [update_menu_item_cache] => 
            [lazy_load_term_meta] => 1
            [update_post_meta_cache] => 1
            [post_type] => 
            [posts_per_page] => 10
            [nopaging] => 
            [comments_per_page] => 5
            [no_found_rows] => 
            [order] => DESC
        )

    [tax_query] => WP_Tax_Query Object
        (
            [queries] => Array
                (
                    [0] => Array
                        (
                            [taxonomy] => category
                            [terms] => Array
                                (
                                    [0] => lake-and-pond-management
                                )

                            [field] => slug
                            [operator] => IN
                            [include_children] => 1
                        )

                    [1] => Array
                        (
                            [taxonomy] => category
                            [terms] => Array
                                (
                                    [0] => 34
                                )

                            [field] => term_id
                            [operator] => IN
                            [include_children] => 
                        )

                )

            [relation] => AND
            [table_aliases:protected] => Array
                (
                    [0] => ph_term_relationships
                    [1] => tt1
                )

            [queried_terms] => Array
                (
                    [category] => Array
                        (
                            [terms] => Array
                                (
                                    [0] => lake-and-pond-management
                                )

                            [field] => slug
                        )

                )

            [primary_table] => ph_posts
            [primary_id_column] => ID
        )

    [meta_query] => WP_Meta_Query Object
        (
            [queries] => Array
                (
                )

            [relation] => 
            [meta_table] => 
            [meta_id_column] => 
            [primary_table] => 
            [primary_id_column] => 
            [table_aliases:protected] => Array
                (
                )

            [clauses:protected] => Array
                (
                )

            [has_or_relation:protected] => 
        )

    [date_query] => 
    [queried_object] => WP_Term Object
        (
            [term_id] => 37
            [name] => Lake and Pond Management
            [slug] => lake-and-pond-management
            [term_group] => 0
            [term_taxonomy_id] => 37
            [taxonomy] => category
            [description] => Good to Know considerations for lake and pond management.
            [parent] => 0
            [count] => 116
            [filter] => raw
            [term_order] => 11
            [cat_ID] => 37
            [category_count] => 116
            [category_description] => Good to Know considerations for lake and pond management.
            [cat_name] => Lake and Pond Management
            [category_nicename] => lake-and-pond-management
            [category_parent] => 0
        )

    [queried_object_id] => 37
    [request] => SELECT SQL_CALC_FOUND_ROWS  ph_posts.ID
					 FROM ph_posts  LEFT JOIN ph_term_relationships ON (ph_posts.ID = ph_term_relationships.object_id)  LEFT JOIN ph_term_relationships AS tt1 ON (ph_posts.ID = tt1.object_id)
					 WHERE 1=1  AND ( 
  ph_term_relationships.term_taxonomy_id IN (37) 
  AND 
  tt1.term_taxonomy_id IN (34)
) AND ((ph_posts.post_type = 'post' AND (ph_posts.post_status = 'publish' OR ph_posts.post_status = 'acf-disabled')))
					 GROUP BY ph_posts.ID
					 ORDER BY ph_posts.menu_order, ph_posts.post_date DESC
					 LIMIT 0, 10
    [posts] => Array
        (
            [0] => WP_Post Object
                (
                    [ID] => 18909
                    [post_author] => 1
                    [post_date] => 2025-12-12 13:55:34
                    [post_date_gmt] => 2025-12-12 13:55:34
                    [post_content] => 

Duke Farms, a Center of the Doris Duke Foundation, is a 2,700-acre landscape in Hillsborough, NJ, dedicated to restoring ecosystems, demonstrating sustainable land management, and inspiring environmental leadership. Once the privately-owned estate of J.B. and Doris Duke, the property now welcomes more than 150,000 visitors annually who come to experience its diverse habitats, miles of public trails, and innovative conservation programs.

Situated within the Raritan River Watershed and bordered by a mosaic of rural and suburban development, Duke Farms functions as a living laboratory for nature-based solutions in complex, fragmented landscapes. Its forests, meadows, waterways, and working lands offer an unparalleled setting to advance climate-positive strategies, including restorative land management and decarbonization initiatives, while maintaining an unwavering commitment to protecting wildlife and enriching biodiversity.

For more than 20 years, Princeton Hydro has partnered with Duke Farms to restore, monitor, and manage its interconnected lakes and ponds. In 2001, we developed a comprehensive Lake Management Plan to address water quality challenges, promote ecological balance, and ensure these systems could support both wildlife and public use. Since then, we have provided ongoing updates to align management strategies with the ecological objectives of the Duke Farms Foundation. Over time, the Foundation has expanded public access for education and recreation, highlighting the distinctions between shallow, artificial impoundments and natural lakes while implementing innovative, nature-based techniques for algae and aquatic plant control. Today, Duke Farms’ 11 lakes and ponds, eight of which were included in the original plan, remain central to the property’s water resources and continue to play a vital role in overall ecological health, stewardship programming, and public recreation opportunities.

Great Falls Cove at Duke Farms. Photo by Princeton Hydro Aquatic Ecologist Katie Walston-Frederick.


Evolving Strategies for an Evolving Landscape

The original Lake Management Plan integrated routine water quality monitoring, hydrologic and pollutant-load modeling, adaptive aquatic plant management, and targeted interventions to restore ecological balance. Key components included invasive species control, such as Common Carp removal to support native fish populations, and a comprehensive algae and aquatic plant program that included aeration and aquascaping. This multifaceted approach established the foundation for long-term recovery across the lake system.

As Duke Farms expanded public access and strengthened its educational mission, management strategies evolved to emphasize innovative, low-impact techniques for shallow, human-made impoundments. Recent advancements implemented by Princeton Hydro include:

  • Floating wetland islands to create habitat, improve aesthetics, and reduce nutrient loads through plant and microbial uptake.
  • Conversion of shallow pond margins to emergent wetlands by manipulating water levels to limit nuisance algal growth.
  • Design and maintenance of 11 submerged aeration systems, nine powered by solar energy in off-grid locations.
[caption id="attachment_18917" align="aligncenter" width="1227"] The photo above shows the aeration system actively circulating water in Otter Lake.[/caption]  

The most recent plan update incorporates techniques that were unavailable when the original plan was developed:

  • Duckweed skimming, a mechanical method that creates controlled currents to collect floating vegetation, opening surface water, and improving aesthetics without chemical treatments.
  • Biochar has been installed in various locations to reduce nutrient concentrations. For example, at Mermaid Pool, which is a key connector between the Reservoir and adjacent waterbodies, biochar trials show promising results in improving clarity and reducing nutrients.
[gallery columns="2" link="none" size="medium" ids="18916,18911"] These initiatives reinforce Duke Farms’ commitment to piloting forward-looking, sustainable ecosystem management practices that can guide stewardship of water resources across the region and beyond.
Hydrology Study: Reducing Pumping, Improving Water Quality

In 2012, Princeton Hydro conducted a detailed hydrologic analysis of Duke Farms’ interconnected lake system to evaluate water management strategies. Historically, water from the Raritan River was pumped into the lakes to maintain water levels. While reliable, this practice introduced elevated nutrients and sediments in the property’s lakes and ponds, degrading water quality and fueling nuisance algal blooms.

The study synthesized pump and discharge records, long-term climate and hydrologic data, and monthly water budgets, and included experimental pumping scenarios to assess alternatives. Results were transformative: under normal conditions, supplemental pumping could be reduced by more than 95%, and even during drought, by about 70%, without compromising lake levels. Based on these findings, Duke Farms adopted a low-volume, seasonal pumping strategy and transitioned to a higher-quality groundwater source, which significantly reduced nutrient loading, improved water clarity, and lowered energy consumption.

[caption id="attachment_18910" align="aligncenter" width="1227"] The Duke Farms Reservoir[/caption]

Ongoing monitoring remains a cornerstone of the Duke Farms–Princeton Hydro partnership. For each waterbody, the team conducts in-situ data collection, laboratory analyses, visual and observational evaluations, and detailed reporting. Data from continuous monitoring demonstrates sustained improvements in dissolved oxygen, water quality, and overall lake/pond health. This continuous feedback loop informs adaptive management decisions and allows Duke Farms to measure the ecological success of its restoration efforts.

We are proud to partner with Duke Farms in advancing the health and resilience of its water resources, a commitment that not only protects the lakes and ponds on the property but also delivers positive ecological benefits throughout the Raritan River watershed. Click here to learn more about our lake management work in the region. To explore Duke Farms, plan a visit to its beautiful property, sign up for educational programs, or discover ways to get involved in its conservation initiatives, visit Duke Farms’ website.

*All photos used in this blog were captured by Princeton Hydro Aquatic Ecologist Katie Walston-Frederick. [post_title] => Two Decades of Lake Management Innovation at Duke Farms [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => two-decades-of-lake-management-innovation-at-duke-farms [to_ping] => [pinged] => [post_modified] => 2025-12-12 16:52:48 [post_modified_gmt] => 2025-12-12 16:52:48 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18909 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => 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] => 2026-01-22 17:53:57 [post_modified_gmt] => 2026-01-22 17:53:57 [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 ) [2] => WP_Post Object ( [ID] => 8948 [post_author] => 1 [post_date] => 2021-07-13 12:50:00 [post_date_gmt] => 2021-07-13 12:50:00 [post_content] =>

Volunteers recently came together in Asbury Park, New Jersey to install floating wetland islands (FWIs) in Wesley Lake and Sunset Lake. The initiative, led by the Deal Lake Commission and Princeton Hydro, brought together dozens of volunteers to install a total of 12 FWIs, six in each lake. 

[gallery link="none" ids="8935,8936,8934"]

Photos by Donald Brockel

 

FWIs are a low-cost, effective green infrastructure solution used to mitigate phosphorus and nitrogen stormwater pollution. FWIs are designed to mimic natural wetlands in a sustainable, efficient, and powerful way. They improve water quality by assimilating and removing excess nutrients that could fuel harmful algae blooms; provide valuable ecological habitat for a variety of beneficial species; help mitigate wave and wind erosion impacts; provide an aesthetic element; and add significant biodiversity enhancement within open freshwater environments.

Volunteers install plants in one of the six floating wetland islands launched in Wesley Lake:

The Deal Lake Commission acquired the 12 FWIs through a Clean Water Act Section 319(h) grant awarded by the New Jersey Department of Environmental Protection. During the volunteer event, participants helped plant vegetation in each of the FWIs, and launch and secure each island into the lakes.

We collected so many great photos during the event. Here are some highlights:

[gallery link="none" columns="2" ids="8950,8939,8943,8942,8946,8944,8945,8954,8941,8923"]

NBC New York’s Brian Thompson stopped by to lend a hand and captured footage of the floating wetland island launch. Click here to watch!

To learn more about Floating Wetland Islands, check out the recent Native Plants, Healthy Planet Podcast, which featured Dr. Jack Szczepanski, CBLP, Princeton Hydro Senior Aquatic Ecologist.

[post_title] => Volunteers Install 12 Floating Wetland Islands in Asbury Park, NJ [post_excerpt] => Volunteers installed floating wetland islands (FWIs) in Asbury Park's Wesley Lake and Sunset Lake. The initiative was led by the Deal Lake Commission and Princeton Hydro. [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => volunteers-install-12-floating-wetland-islands-in-asbury-park-nj [to_ping] => [pinged] => [post_modified] => 2024-01-18 05:26:33 [post_modified_gmt] => 2024-01-18 05:26:33 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=8948 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 5284 [post_author] => 3 [post_date] => 2020-07-28 11:34:38 [post_date_gmt] => 2020-07-28 11:34:38 [post_content] =>

This month we are launching the first blog in our Client Spotlight Blog Series! Each spotlight will feature one of our important client relationships in order to give you an inside look at our collaboration. We pride ourselves on forming strong ties with organizations that share our values of creating a better future for people and our planet. So we are excited to be able to share snippets of the incredible teamwork we've been able to accomplish over the years!

At Princeton Hydro, we value our client relationships, as the collaborative work we are able to complete with organizations like the Lake Hopatcong Foundation (LHF) reaches exponentially further than anything we could complete alone. One of the reasons our organizations have such strong symmetry is that our values align and complement each other.

As their mission states,”Lake Hopatcong Foundation dedicates itself to protecting the lake environment and enhancing the lake experience, bringing together public and private resources to encourage a culture of sustainability and stewardship on and around New Jersey’s largest lake, for this and future generations.” We are so proud to help protect New Jersey’s largest lake with LHF.

We have been working with LHF since its inception in 2012, which is why we are excited to feature them in our first client spotlight blog. We spoke with Jessica Murphy, President/Executive Director of the Foundation, and Donna Macalle-Holly, Grants and Program Director, to give you an insider look at the organization:

Q: What makes the Lake Hopatcong Foundation unique?

A: The Lake Hopatcong Foundation is unique in that our mission spans a wide spectrum of activities. In addition to projects that focus on the lake environment, we also take on initiatives that support education, safety, community-building, recreation, and even arts and culture. The lake is split between two counties and four towns, so bringing the community together for all these things is very important to us, in addition to making sure the lake itself is healthy.

Q: What does the Lake Hopatcong Foundation value?

A: During our strategic planning process, the board and staff developed a list of values that we go back to when operating and making decisions. They are:

  • Collaboration - We operate in a way that brings people together throughout the community.
  • Action - We are committed to our mission, moving quickly to take on projects that have an impact on and around the lake.
  • Sustainability - We are forward-thinking when making decisions, taking future generations into account when considering projects and initiatives.
  • Warmth - We are a friendly face to the community, showing the best of ourselves and bringing out the best in the people of Lake Hopatcong.
Q: How long have you been working with Princeton Hydro?

When we first started the Lake Hopatcong Foundation in 2012, Dr. Fred Lubnow was kind enough to do a water quality presentation as one of our very first events as an organization! In the years since, we’ve worked closely with Princeton Hydro, particularly in a support role as they conduct business with the Lake Hopatcong Commission. The Lake Hopatcong Commission is a state entity created in 2001 through the Lake Hopatcong Protection Act dedicated to protecting the water quality of Lake Hopatcong and to preserve the natural, scenic, historical and recreational resources of the lake. LHF funded Princeton Hydro’s water quality monitoring during the years that the Commission ran out of money

Q: What types of services has Princeton Hydro provided to your organization?

A: In addition to water quality monitoring on the lake, Princeton Hydro has led volunteer training for us in our efforts to prevent the spread of invasive species and to teach local students in our spring field trip program. Dr. Lubnow has also worked alongside us in applying for grants and in providing insight and expertise for other environmental projects at the lake, including helping guide the installation of floating wetland islands, and helping our NJ Lakes Group to work with NJDEP on Harmful Algal Bloom (HAB) policies. He even did a quick fact check on our children’s book, Lake Hopatcong Speaks Out, before we published it!

Q: Do you have a favorite or most memorable project we’ve worked on together?

A: The days that Chris Mikolajczyk spent teaching our volunteers about how to find and remove water chestnuts from the lake were a lot of fun, particularly because we were kayaking on the lake for it! And, also because the kayak we provided Chris was too small for him, and he had to scrunch in to fit, but he was a trouper and paddled on.

Q: What are some exciting things your organization is working on right now?

A: We are working closely with Princeton Hydro and LHC on a series of projects, funded through NJDEP grants, LHC, LHF, and local governments, that we hope will prevent and mitigate HABs on the lake. Those projects include aeration systems, phosphorus-locking technologies, and stormwater infrastructure upgrades. We’re excited to see how effective each can be. Also, on August 7 at 12:30, Dr. Lubnow will be presenting the Lake Hopatcong water quality monitoring project results at LHF’s “Thirst for Knowledge” lunch-and-learn webinar series, which was created to share information and discuss topics of interest to our lake community. To register for the free webinar, visit lakehopatcongfoundation.org.

[caption id="attachment_5249" align="aligncenter" width="584"]Photo by: Colleen Lyons of the Lake Hopatcong Commission  [/caption] Q: What drives you to want to go to work every day?

A: All of us at Lake Hopatcong Foundation have a passion for this lake and want to see it protected; we have a love for the community that surrounds it, too. Jessica Murphy grew up on the lake, met her husband here, and now is raising her four children to love the lake, too. Donna Macalle-Holly also met her husband on Lake Hopatcong, lives on the lake, and has worked professionally to take care of it for nearly two decades. Everyone in our office has made memories on Lake Hopatcong and developed friendships with those who live and work here. Those personal connections fuel our passion for what we do.

Q: How can Princeton Hydro support you/your organization in the future?

A: Continue to be the incredible resource you are! We are so fortunate to have the deep knowledge and expertise that Fred and your entire team provide, and we look forward to continuing to work together in the years ahead.

[caption id="attachment_5286" align="aligncenter" width="576"]  [/caption]

Some recent projects we are/have been working on with LHF include installing biochar bags to help control phosphorus levels and applying Phoslock to help mitigate harmful algal blooms! Because of our history working on Lake Hopatcong, we too have gained a passion for protecting and maintaining this lake. This incredibly important work could not be done without the genuine devotion and dedication from the Lake Hopatcong Foundation. We look forward to continuing great work with this incredible group!

[post_title] => Client Spotlight: Lake Hopatcong Foundation [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => client-spotlight-lake-hopatcong-foundation [to_ping] => [pinged] => [post_modified] => 2025-11-04 02:46:03 [post_modified_gmt] => 2025-11-04 02:46:03 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5284 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [4] => WP_Post Object ( [ID] => 4934 [post_author] => 3 [post_date] => 2020-05-27 13:51:06 [post_date_gmt] => 2020-05-27 13:51:06 [post_content] =>

Last summer, 39 of New Jersey’s lakes were plagued with toxic algae outbreaks, also known as harmful algae blooms or HABs, causing major water quality degradation, beach closures and health advisories. In response, the NJDEP implemented a unified statewide approach to addressing HABs in freshwater recreational waters and sources of drinking water, and protecting the public from risks associated with exposure to cyanobacteria.

Last week, NJDEP announced a new component to its statewide Cyanobacterial HAB Response Strategy: a color-coded health alert index that provides precise recreational use recommendations for impacted waterbodies based on levels of cyanobacteria and/or cyanotoxins present. The index has six tiers - NONE, WATCH, ALERT, ADVISORY, WARNING, and DANGER - each providing recommendations on the specific activities that should or should not be pursued based on water monitoring results.

"Princeton Hydro is proud to be one of the contributing factors in the development of the Updated Guidance for HABs," said said Dr. Fred Lubnow, Director of Aquatic Resources for Princeton Hydro. "We feel this updated protocol will provide the necessary and objective information for State and local organizations to make informed and rational decisions, based on sound and scientifically-based data, on how to deal with HABs in a recreational setting."

Princeton Hydro and Clean Water Consulting are the technical advisers for the New Jersey Lake Group, who have met a number of times over the last 8 to 9 months to discuss the State's guidance on dealing with HABs.  In late 2019, on behalf of the New Jersey Lake Group, Princeton Hydro and Clean Water Consulting developed a White Paper providing recommended changes for consideration to NJDEP's Recreational Response Strategy to HABs.

"I'm proud to say that many of the provided recommendations were integrated into NJDEP's Updated Guidance for HABs," explained Dr. Lubnow.

WATCH (Suspected or confirmed HAB with potential for allergenic and irritative health effects) This warning will be posted when HAB cell counts exceed 20,000. In this scenario, public beaches remain open, but the index instructs the public to use caution, provides information on the potential less serious health effects, and allows for more informed decision-making.

ALERT (Confirmed HAB that requires greater observation due to increasing potential for toxin production) This warning indicates a public bathing beach closure only and is posted when a HAB has been confirmed with cell counts between 40,000 and 80,000 and no known toxins above the public threshold. Beaches remain open (dependent upon local health authority) and monitoring for future toxin production should be increased.

ADVISORY (Confirmed HAB with moderate risk of adverse health effects and increased potential for toxins above public health thresholds) Signs will be posted for this warning level when cell counts exceed 80,000 or when toxin levels exceed 3 micrograms per milliliter of microcystins. Public bathing beaches will be closed, but the waterbody will remain accessible to some “secondary contact” activities, like boating.

WARNING and DANGER (Confirmed HAB with high risk of adverse health effects due to high toxin levels) and (Confirmed HAB with very high risk of adverse health effects due to high toxin levels) These tiers are designed to alert the public to the presence of HABs that are producing very high levels of toxins which justify additional caution. In some instances, the entire waterbody may be closed for all public use. New Jersey has experienced approximately 12 “warning level” HAB events over the last 3 years; monitoring has never indicated a “danger level” HAB event.

According to their press release, NJDEP is committed to working with local officials to implement the index and get signage posted at lakes throughout the state as soon as possible.

In order to create the health index, NJDEP scientists carefully reviewed HABs data collected over the last three years by Lake Hopatcong Commission, Lake Hopatcong Foundation, Princeton Hydro, and other sources. The tiered warning system will enable lake communities, residents and visitors to make more individualized decisions about what risks they are willing to take and what activities they feel comfortable engaging in at the various levels of HABs.

In the coming days, the NJDEP’s Harmful Algal Bloom website will be updated to include the new health index and accompanying signage, relevant monitoring data, and other information for each of the impacted bodies of water, as well as an updated HAB Monitoring and Response Strategy. For now, you can read the full press release and additional information here: https://www.nj.gov/dep/newsrel/2020/20_0023.htm.

To learn more about HABs, check out our recent blog:

[embed]https://www.princetonhydro.com/blog/harmful-algae-blooms/[/embed]

[post_title] => NJDEP Releases Updated Guidance for Harmful Algal Blooms [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => njdep-habs-guidelines [to_ping] => [pinged] => [post_modified] => 2025-01-02 13:54:12 [post_modified_gmt] => 2025-01-02 13:54:12 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4934 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [5] => WP_Post Object ( [ID] => 1615 [post_author] => 3 [post_date] => 2020-03-20 12:14:14 [post_date_gmt] => 2020-03-20 12:14:14 [post_content] => Photo from: New York State Department of Environmental Conservation, water chestnut bed at Beacon Spring is officially here! Tulips will soon be emerging from the ground, buds blossoming on trees and, unfortunately, invasive plant species will begin their annual growing cycle. No type of habitat or region of the globe is immune to the threat of invasive species (“invasives”). Invasives create major impacts on ecosystems throughout the world, and freshwater ecosystems and estuaries are especially vulnerable because the establishment of such species in these habitats is difficult to contain and reverse. This blog provides an introduction to invasive aquatic species, including information that will help you prevent the spread of invasives in the waterways of your community.
Defining Invasive Species
Invasive species can be defined as non-native occurring in an ecosystem that is outside its actual natural or native distributional range. Although the colonization of an ecosystem by non-native species can occur naturally, it is more often a function of human intervention, both deliberate and accidental. For aquatic ecosystems some species have become established as a result of the aquarium trade, fish culture practices and/or transport of plants and animals in the bilge and ballast water of trans-oceanic shipping vessels. One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced. The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives very often cause serious harm to the environment, the economy, and even human health. A prominent example is the Emerald Ash Borer, a non-native, invasive beetle that is responsible for the widespread death of ash trees. As noted above, there are a large number of aquatic invasive species. Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds and reservoirs include:
Understanding How Invasives Spread
Either intentionally or unintentionally, people have helped spread invasives around the globe. This is not a recent phenomenon but rather something that has been occurring for centuries. “Intentional introductions,” the deliberate transfer of nuisance species into a new environment, can involve a person pouring their home aquarium into a lake or deliberate actions intended to improve the conditions for various human activities, for example, in agriculture, or to achieve aesthetics not naturally available. Photo by: Tom Britt/CC Flickr, zebra Mussels adhered to a boat propeller“Unintentional introductions” involve the accidental transfer of invasives, which can happen in many ways, including aquatic species attached to the hull of boats or contained in bilge and ballast water. A high-profile example is the introduction of zebra mussels to North America. Native to Central Asia and parts of Europe, zebra mussels accidentally arrived in the Great Lakes and Hudson River via cargo ships traveling between the regions. The occurrence, density, and distribution of Zebra mussels occurred at an alarming rate, with the species spreading to 20 states in the United States and to Ontario and Quebec in Canada. Due to their reproductive fecundity and filter-feeding ability, they are considered the most devastating aquatic invasive species to invade North American fresh waters. They alter and diminish the plankton communities of the lakes that they colonize leading to a number of cascading trophic impacts that have especially negative consequences on fisheries. Zebra mussel infestations have also been linked to increased cyanobacteria (bluegreen algae) blooms and the occurrence of harmful algae blooms (HABs) that impact drinking water quality, recreational use, and the health of humans, pets, and livestock. Additionally, higher than average temperatures and changes in rain and snow patterns caused by climate change further enable some invasive plant species to move into new areas. This is exemplified by the increased northly spread of hydrilla (Hydrilla verticillate), a tropical invasive plant species that has migrated since its introduction in Florida in the 1950s to lakes, rivers, and reservoirs throughout the U.S. Regardless of how any of these invasive species first became established, the thousands of terrestrial and aquatic invasive species introduced into the U.S. have caused major ecological, recreational and economic impacts.
Measuring the Impacts of Invasives
After habitat loss, invasive, non-native species are the second largest threat to biodiversity. According to The Nature Conservancy, “Invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States. The annual cost to the nation’s economy is estimated at $120 billion a year, with over 100 million acres (an area roughly the size of California) suffering from invasive plant infestations. Invasive species are a global problem — with the annual cost of impacts and control efforts equaling 5% of the world’s economy.” Of the $120 billion, about $100 million per year is spent on aquatic invasive plant control to address such deleterious issues as:
  • Human health (West Nile Virus, Zika Virus)
  • Water quality impacts (Canada geese)
  • Potable water supplies (Zebra mussel)
  • Commercial fisheries (Snake head, lamprey, Eurasian ruffe, round goby)
  • Recreational activities (Eurasian watermilfoil, water chestnut, hydrilla)
  • Biodiversity (Purple loosestrife, common reed, Japanese knotweed)
Invasive species can change the food web in an ecosystem by destroying or replacing native food sources. As the National Wildlife Federation explains, “The invasive species may provide little to no food value for native wildlife. Invasive species can also alter the abundance or diversity of species that are important habitat for native wildlife. Additionally, some invasive species are capable of changing the conditions in an ecosystem, such as changing soil chemistry...”
Addressing Invasives
Our native biodiversity is an irreplaceable and valuable treasure. Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can help protect our native heritage from damage by invasive species.
What Can We Do?
  • Reduce the spread
  • Routinely monitor
  • Document and report
  • Spread the word
Reducing the Spread:
The best way to fight invasive species is to prevent them from occurring in the first place. There are a variety of simple things each of us can do to help stop the introduction and spread of invasives.
  • Plant native plants on your property and remove any invasive plants. Before you plant anything, verify with your local nursery and check out this online resource for help in identifying invasive plants.
  • Thoroughly wash your gear and watercraft before and after your trip. Invasives come in many forms – plants, fungi and animals – and even those of microscopic size can cause major damage.
  • Don't release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research to make sure you can commit to looking after it. Look into alternatives to live bait.
Monitoring:
Invasive plant monitoring is one of the most valuable site­-level activities people can support. Contact your local watershed organizations to inquire about watershed monitoring volunteer opportunities. For example, the Lake Hopatcong “Water Scouts” program was established to seek out and remove any instances of the invasive water chestnut species. If you are a lake or watershed manager, the best way to begin an invasive plant monitoring project is with an expert invasive plant survey to determine which invasives are most likely to be problematic in your watershed and identify the watershed’s most vulnerable areas. Contact us to learn more.
Documenting and Reporting:
It’s important to learn to identify invasive species in your area and report any sightings to your county extension agent or local land manager. For example, in New Jersey there is the Invasive Species Strike Team that tracks the spread of terrestrial and aquatic invasives and works with local communities in the management of these species. Additionally, consider developing a stewardship plan for your community to help preserve its natural resources. Princeton Hydro’s team of natural resource scientists can help you get the ball rolling by preparing stewardship plans focused on controlling invasive species and protecting the long-term health of open spaces, forests habitats, wetlands, and water-quality in your community.
Spreading the word:
Many people still don’t understand the serious implications of invasive species. Education is a crucial step in stopping the spread of invasives, which is why it’s so important to talk with your neighbors, friends and family about the hazards and ecological/economic impacts of invasive species. Also consider talking with your community lake or watershed manager about hosting an educational workshop where experts can share their knowledge about invasives specific to your area and how best to address them.   We encourage you to share this article and spread your invasive species knowledge so that together we can help stop the introduction and spread of invasive species.

[post_title] => Understanding and Addressing Invasive Species [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => invasive-species [to_ping] => [pinged] => [post_modified] => 2025-06-25 16:14:40 [post_modified_gmt] => 2025-06-25 16:14:40 [post_content_filtered] => [post_parent] => 0 [guid] => http://www.princetonhydro.com/blog/?p=1615 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 1 [filter] => raw ) [6] => WP_Post Object ( [ID] => 4361 [post_author] => 3 [post_date] => 2019-11-18 15:07:38 [post_date_gmt] => 2019-11-18 15:07:38 [post_content] =>

Harmful Algae Blooms (HABs) were in the spotlight this summer due to the severe impacts they had on lakes throughout the country. The nation-wide HABs outbreak caused beach closures, restricted access to lake usage, and wide-ranging health advisories.

What exactly are HABs? Why were they so severe this summer? Will this trend continue? Can anything be done to prevent the occurrence or mitigate the impacts?

In this blog, we provide answers to all of those questions, exploring what HABs are, why they occur, why they were particularly prevalent this summer, and what we can do to combat them.

[caption id="attachment_1736" align="alignnone" width="1246"]Harmful Algae Bloom Visible in Owasco Lake. Photo by: Tim Schneider Harmful Algae Bloom Visible in Owasco Lake. Photo by: Tim Schneider[/caption]

What are HABs?

Simply put, HABs are rapid, large overgrowths of cyanobacteria. Cyanobacteria, also known as blue-green algae, aren’t actually algae, they are prokaryotes, single-celled aquatic organisms that are closely related to bacteria and can photosynthesize like algae. These microorganisms are a natural part of aquatic ecosystems, but, under the right conditions (primarily heavy rains, followed by hot, sunny days), these organisms can rapidly increase to form cyanobacteria blooms, also known as HABs.

HABs can cause significant water quality issues in lakes and ponds, often forming a visible and sometimes odorous scum on the surface of the water. They can produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms.

HABs also negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes and waterways.


What Causes HABs?

HABs are caused by a complex set of conditions, and many questions remain about exactly why they occur and how to predict their timing, duration, and toxicity. Primarily, HABs are caused by warmer temperatures and stormwater run-off pollutants, including fertilizers with phosphates.

NY Times article, featuring Princeton Hydro, looks at how climate change affects lakes nationwide, using NJ as an example. Photo by: Rick Loomis, NY Times.HABs are induced by an overabundance of nutrients in the water. The two most common nutrients are fixed nitrogen (nitrates and ammonia) and phosphorus. Discharges from wastewater treatment plants, runoff from agricultural operations, excessive fertilizer use in urban/suburban areas, and stormwater runoff can carry nitrogen and phosphorus into waterways and promote the growth of cyanobacteria.

Climate change is also a factor in HAB outbreaks, which typically occur when there are heavy rains followed by high temperatures and sunshine. Climate change is leading to more frequent, more intense rainstorms that drive run-off pollutants into waterways, coupled with more hot days to warm the water. These are the ideal conditions for HABs, which in recent years have appeared in more places, earlier in the summer.

With climate change and increasing nutrient pollution causing HABs to occur more often and in locations not previously affected, it's important for us to learn as much as we can about HABs so that we can reduce their harmful effects.


How to Prevent HABs?

Signs on the closed beach at Hopatcong State Park warn residents of the Harmful Algae Bloom at Lake Hopatcong on July 2019, in Landing, NJ. (Photo by: Danielle Parhizkaran of NorthJersey.comThe number one thing individuals can do to protect their waterbodies and prevent HABs is to reduce phosphorous use and reduce nutrient loads to waters.

According to Dr. Fred Lubnow of Princeton Hydro, “Managing loads of phosphorous in watersheds is even more important as the East Coast becomes increasingly warmer and wetter thanks to climate change. Climate change will likely need to be dealt with on a national and international scale. But local communities, groups, and individuals can have a real impact in reducing phosphorous levels in local waters.”

Here are a few steps you can take to improve water quality in your community lakes:

Controlling stormwater runoff is another critical factor in improving water quality and reducing HABs. There are a number of low-cost green infrastructure techniques that can be implemented on an individual and community-wide scale. Click here to read more about green infrastructure stormwater management techniques.

In a recent Op/Ed published on NJ.com, Princeton Hydro President Geoffrey M. Goll, P.E. lists four things that residents, businesses, and local governments should do to prevent another HABs outbreak next summer:

  1. Improve aging “gray” infrastructure
  2. Invest in “green” stormwater infrastructure
  3. Implement regional/watershed-based planning
  4. Pass the Water Quality Protection and Jobs Creation Act

"By making the necessary investments, we can simultaneously create jobs, reduce flood impacts, improve fisheries, maintain or increase lakefront property values, improve water quality and preserve our water-based tourism. The time to act is literally now," said Geoff. Go here, to read the full article.


HABs Management in Action through Floating Wetland Islands

Nitrogen and phosphorus are utilized by plants, which means they uptake these nutrients to sustain growth. We see this naturally occurring in wetland ecosystems where wetlands act as a natural water filtration system and can actually thrive from nutrients flowing in from external sources.

This process is replicated in floating wetland islands (FWIs), where you typically have a constructed floating mat with vegetation planted directly into the material. The plants then grow on the island, rooting through the floating mat.

[caption id="attachment_4363" align="aligncenter" width="554"]This illustration, created by Staff Scientist Ivy Babson, conveys the functionality of a Floating Wetland Island This illustration, created by Staff Scientist Ivy Babson, conveys the functionality of a Floating Wetland Island[/caption]  

Not only do FWIs assimilate and remove excess nitrogen and phosphorus out of the water, they also provide habitat for fish and other aquatic organisms; help mitigate wave and wind erosion impacts; provide an aesthetic element; and can be part of a holistic lake/pond management strategy. Because of this, FWIs are being utilized to improve water quality and control HABs in lakes and ponds throughout the country.

[gallery link="none" size="medium" ids="17718,17310,10666"]

Princeton Hydro has designed and implemented numerous FWIs in waterbodies large and small. Go here to learn how they’re being used in Harveys Lake.


Recognizing and monitoring the changes that are taking place in our local waterways brings the problems of climate change, stormwater pollution and the resulting water quality issues closer to home, which can help raise awareness, inspire environmentally-minded action and promote positive, noticeable change.

If you spot what you believe to be HABs in your community lake, contact your local lake association right away. They, along with their lake management team, can assess the situation and determine what further actions need to be taken. For more information about HABs, click here.

Special thanks to Princeton Hydro Staff Scientist Ivy Babson for her contributions to this blog.

[post_title] => Identifying, Understanding and Addressing Harmful Algae Blooms [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => harmful-algae-blooms [to_ping] => [pinged] => [post_modified] => 2025-11-04 02:33:38 [post_modified_gmt] => 2025-11-04 02:33:38 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4361 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [7] => WP_Post Object ( [ID] => 5846 [post_author] => 3 [post_date] => 2019-09-19 08:04:13 [post_date_gmt] => 2019-09-19 08:04:13 [post_content] =>

The U.S. is home to thousands of lakes both natural and manmade. Lakes are incredibly important features in the landscape that provide numerous beneficial services, including domestic water supply, hydro-electric power, agricultural water supply, recreation, and tourism. They also provide essential habitat for fish, wildlife and aquatic organisms.

Lakes are complex and dynamic systems, each situated in a unique landscape context. Maintaining the ecological health of a lake is no easy feat. A lot goes on behind the scenes to maintain water quality and a balanced lake ecosystem. Successful, long-term lake management requires a proactive approach that addresses the causes of its water quality problems rather than simply reacting to weed and algae growth and other symptoms of eutrophication.

Chautauqua Magazine recently published an article about the science behind the management of Chautauqua Lake, which features our Director of Aquatic Programs Dr. Fred Lubnow. We’ve included an excerpt below. Click here to view the full article and photos:

Dr. Fred Lubnow is a scientist and director of aquatic programs at Princeton Hydro, a consulting organization based in Exton, Pennsylvania, that is often called on to support lake and watershed regions that want to develop a long-term plan for lake conservation.

He says that while his firm focuses on the development of data and intelligence to inform decision making in regard to freshwater ecosystems, his work is really about coalition building.

"As a scientist and a consultant, you learn over time that you are building a coalition stakeholders and determining what we can agree on to help everyone in the community," Lubnow said.

Ten years ago, Princeton Hydro was hired to do some stream and inlet monitoring for various stakeholders at Chautauqua Lake. More recently, they've been contracted to conduct third-party monitoring of the impacts of the Spring 2019 herbicide applications in the south basin of Chautauqua Lake...

Continue reading!
 

Princeton Hydro is the industry leader in lake restoration and watershed management. We have conducted diagnostic studies and have developed management and restoration plans for over 300 lakes and watersheds throughout the country. This has included work for public and private recreational lakes, major water supply reservoir, and watershed management initiatives conducted as part of USEPA and/or state funded programs. For more information about our lake management services, go here: http://bit.ly/pondlake. 

[post_title] => Dr. Fred Lubnow of Princeton Hydro Featured in Magazine Article on Chautauqua Lake [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => chautauqua-lake [to_ping] => [pinged] => [post_modified] => 2025-10-13 15:59:22 [post_modified_gmt] => 2025-10-13 15:59:22 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4158 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 1 [filter] => raw ) [8] => WP_Post Object ( [ID] => 5843 [post_author] => 3 [post_date] => 2019-09-10 23:44:50 [post_date_gmt] => 2019-09-10 23:44:50 [post_content] =>
NorthJersey.com File Photo
The Borough of Ringwood initiates a unique public-private partnership with four community lake associations to holistically manage watershed health related to private lakes

Providing drinking water to millions of New Jersey residents, the Borough of Ringwood is situated in the heart of the New Jersey Highlands and is home to several public and private lakes that sit within the Ramapo Mountains. In order to take an active role in the management of these natural resources within multiple watersheds, the Borough of Ringwood will be the first municipality in the state of New Jersey to take a regional approach to private lake management through a public-private partnership (PPP) with four lake associations.

The four private sets of lakes targeted in the plan— Cupsaw, Erskine, Skyline, and Riconda —were created by the Ringwood Company in the 1920s and 30s to promote the municipality as a hunting and fishing retreat and a summer resort. They currently provide private beach clubs and recreational opportunities for surrounding homeowners who can opt to join as members.

Map Showing the Four Private Lakes in the PPP holistic watershed management plan Generally, the health of a private lake is funded and managed in isolation by the governing private lake association group. Ringwood Borough Manager Scott Heck’s concept was to design and implement a municipal-wide holistic watershed management plan to use as a tool to identify capital priorities to enhance water quality throughout the community. Mr. Heck hired Princeton Hydro, a leader in ecological and engineering consulting to design this innovative project.

Cupsaw Lake “This regional approach to lake and watershed management is a no-brainer from a scientific, technical, and community point of view. Historically, however, municipal governments and private lake associations have rarely partnered to take such an approach,” said Princeton Hydro’s Senior Project Manager, Christopher Mikolajczyk, who is a Certified Lake Manager and lead designer for this initiative. “We’re thrilled to work with the Borough of Ringwood and the New Jersey Highlands Council to set a precedent for this logical watershed management strategy, which opens the door for future public-private partnerships.”

As part of this project, a Watershed-based Assessment will be completed. The following objectives will be met:

  1. Identification, quantification, and prioritization of watershed-based factors which may cause eutrophication;
  2. Identification of watershed management measures needed to address general causes of water quality impairments;
  3. Identification of the relative cost of the recommended general watershed management measures;
  4. The generation of a schedule, based on priority, for the implementation of the recommended watershed management measures; and
  5. A general assessment report will be authored at the conclusion of the study.

Skyline Lake in the FallFunding for the Watershed-based Assessment for the Lakes of the Borough of Ringwood is being provided by the New Jersey Highlands Council through a grant reimbursement to the Borough of Ringwood. As part of the PPP , the Borough of Ringwood will review and where feasible implement any suggested actions surrounding the lakes. The final report, provided to the Borough by Princeton Hydro, will identify and prioritize watershed management techniques and measures that are best suited for immediate and long-term implementation, as well as provide cost projections for implementation in both the short-term and long-term.

This integrated approach to watershed and lake management is an important preventative measure to improve water quality for millions of people and reduce potential future incidents of aquatic invasive species and harmful algal blooms throughout the region.

For more information about the PPP, check out today's NorthJersey.com news story. To learn more about Princeton Hydro's lake and pond management services, go here: http://bit.ly/pondlake.

[post_title] => BOROUGH OF RINGWOOD INITIATES FIRST-IN-STATE REGIONAL APPROACH TO LAKE MANAGEMENT THROUGH PUBLIC-PRIVATE PARTNERSHIP [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => borough-of-ringwood [to_ping] => [pinged] => [post_modified] => 2025-10-13 15:59:24 [post_modified_gmt] => 2025-10-13 15:59:24 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4148 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [9] => WP_Post Object ( [ID] => 5838 [post_author] => 3 [post_date] => 2019-08-08 16:13:09 [post_date_gmt] => 2019-08-08 16:13:09 [post_content] =>

Measuring 630+ acres, Harveys Lake, located in Luzerne County, Pennsylvania, just northeast of Wilkes-Barre, is the largest natural lake (by volume) within the Commonwealth of Pennsylvania, and is one of the most heavily used lakes in the area. It is classified as a high quality - cold water fishery habitat (HQ-CWF) and is designated for protection under the classification.

Since 2002, The Borough of Harveys Lake and the Harveys Lake Environmental Advisory Council  has worked with Princeton Hydro on a variety of lake management efforts focused around maintaining high water quality conditions, strengthening stream banks and shorelines, and managing stormwater runoff.

Successful, sustainable lake management requires identifying and correcting the cause of eutrophication as opposed to simply reacting to the symptoms of eutrophication (algae and weed growth). As such, we collect and analyze data to identify the problem sources and use these scientific findings to develop a customized management plan that includes a combination of biological, mechanical, and source control solutions. Here are some examples of the lake management strategies we've utilized for Harveys Lake:

 
Floating Wetland Islands

Floating Wetland Islands (FWIs) are an effective alternative to large, watershed-based natural wetlands. Often described as self-sustaining, FWIs provide numerous ecological benefits. They assimilate and remove excess nutrients, like nitrate and phosphorous, that could fuel algae growth; provide habitat for fish and other aquatic organisms; help mitigate wave and wind erosion impacts; and provide an aesthetic element. FWIs are also highly adaptable and can be sized, configured, and planted to fit the needs of nearly any lake, pond, or reservoir.

Five floating wetland islands were installed in Harveys Lake to assimilate and reduce nutrients already in the lake. The islands were placed in areas with high concentrations of nutrients, placed 50 feet from the shoreline and tethered in place with steel cables and anchored. A 250-square-foot FWI is estimated to remove up to 10 pounds of nutrients per year, which is significant when it comes to algae.

Princeton Hydro worked with the Harveys Lake Environmental Advisory Council and the Borough of Harveys Lake to obtain funding for the FWIs through the Pennsylvania Department of Environmental Protection (PADEP).

 
Streambank & Shoreline Stabilization

The shoreline habitat of Harveys Lake is minimal and unusual in that a paved road encompasses the lake along the shore with most of the homes and cottages located across the roadway, opposite the lake. In addition to the lake being located in a highly populated area, the limited shoreline area adds to the challenges created by urban stormwater runoff.

Runoff from urban lands and erosion of streambanks and shorelines delivers nutrients and sediment to Harveys Lake. High nutrient levels in the lake contribute to algal blooms and other water quality issues. In order to address these challenges, the project team implemented a number of small-scale streambank and inlet stabilization projects with big impacts.

The work included the stabilization of the streambank downstream for Harveys Lake dam and along Harveys Creek, the design and installation of a riparian buffer immediately along the lake’s shoreline, and selective dredging to remove sediment build up in critical areas throughout the watershed.

 
Invasive Species Management

Hydrilla (Hydrilla verticillata), an aggressively growing aquatic plant, took root in the lake in 2014 and quickly infected 250 acres of the lake in a matter of three years. If left untreated, hydrilla will grow to the water’s surface and create a thick green mat, which prevents sunlight from reaching native plants, fish and other organisms below. The lack of sunlight chokes out all aquatic life.

In order to prevent hydrilla from spreading any further, Princeton Hydro and SePRO conducted an emergency treatment of the impacted area utilizing the systemic herbicide Sonar® (Fluridone), a clay-based herbicide. SonarOne, manufactured by SePRO, blocks hydrilla’s ability to produce chloroplasts, which in turn halts the photosynthetic process. The low-concentration herbicide does not harm fish, wildlife or people using the lake. Surveys conducted after the treatment showed it was working – the hydrilla had turned white and was dying off. Additional Sonar treatments followed and efforts to eradicate hydrilla in the lake continue.

Dr. Fred Lubnow, our Director of Aquatic Programs, estimates complete eradication of the aquatic plant could take around five years. Everyone can do their part in preventing the spread of this and other invasive species. Boaters and lake users must be vigilant and remove all vegetation from the bottom of watercrafts and trailers.

 
Stormwater Best Management Practices (BMPs)

In 2009, Princeton Hydro developed a stormwater implementation plan (SIP) for Harveys Lake. The goal of the stormwater/watershed-based efforts was to reduce the lake’s existing annual total phosphorus load to be in full compliance with the established Total Maximum Daily Load (TMDL). This TMDL is related to watershed-based pollutant loads from total phosphorus (TP) and total suspended solids (TSS), which can contribute to algal blooms.

A number of structural urban runoff projects were implemented throughout the watershed. This includes the design and construction of two natural stream channel projects restoring 500 linear feet of tributaries and reducing the sediment and nutrient loads entering the lake. A series of 38 urban runoff BMPs, including nutrient separating devices and roadside infiltration, were installed in areas immediately adjacent to the lake to further reduce the loads of nutrients and other pollutants reaching the lake.

The photos below show a stormwater project that was completed in the Hemlock Gardens Section of the Watershed. Hemlock Gardens is a 28-acre section of land located in the southeastern portion of the watershed. It contains approximately 26 homes, has very steep slopes, unpaved dirt roads, and previously had no stormwater infrastructure in place.

Two structural stormwater BMPs were installed:

  • A nutrient separating baffle box, which utilizes a three-chamber basin with screens to collect leaf litter, grass clippings and trash
  • A water polishing unit that provides a platform for secondary runoff treatment

In 1994, Harveys Lake was identified as “impaired” by PADEP due to large algal blooms. In 2014, Harveys Lake was removed from the list of impaired waters. Project partners attribute the recovery of this lake to the stream restoration, urban runoff BMP implementation, and the use of in-lake nutrient reduction strategies.

The Harveys Lake Watershed Protection Plan Implementation Project proved that despite the lake being located in an urbanized watershed, it is possible to implement cost-effective green infrastructure and stormwater retrofit solutions capable of significantly decreasing pollutant loading to the lake.

To learn more about our lake and pond management services or schedule a consultation, visit: http://bit.ly/pondlake.

[post_title] => Managing Urban Stormwater Runoff and Revitalizing Natural Habitat at Harveys Lake [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => urban-stormwater-runoff-harveys-lake [to_ping] => [pinged] => [post_modified] => 2025-11-04 02:24:07 [post_modified_gmt] => 2025-11-04 02:24:07 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4037 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) ) [post_count] => 10 [current_post] => -1 [before_loop] => 1 [in_the_loop] => [post] => WP_Post Object ( [ID] => 18909 [post_author] => 1 [post_date] => 2025-12-12 13:55:34 [post_date_gmt] => 2025-12-12 13:55:34 [post_content] =>

Duke Farms, a Center of the Doris Duke Foundation, is a 2,700-acre landscape in Hillsborough, NJ, dedicated to restoring ecosystems, demonstrating sustainable land management, and inspiring environmental leadership. Once the privately-owned estate of J.B. and Doris Duke, the property now welcomes more than 150,000 visitors annually who come to experience its diverse habitats, miles of public trails, and innovative conservation programs.

Situated within the Raritan River Watershed and bordered by a mosaic of rural and suburban development, Duke Farms functions as a living laboratory for nature-based solutions in complex, fragmented landscapes. Its forests, meadows, waterways, and working lands offer an unparalleled setting to advance climate-positive strategies, including restorative land management and decarbonization initiatives, while maintaining an unwavering commitment to protecting wildlife and enriching biodiversity.

For more than 20 years, Princeton Hydro has partnered with Duke Farms to restore, monitor, and manage its interconnected lakes and ponds. In 2001, we developed a comprehensive Lake Management Plan to address water quality challenges, promote ecological balance, and ensure these systems could support both wildlife and public use. Since then, we have provided ongoing updates to align management strategies with the ecological objectives of the Duke Farms Foundation. Over time, the Foundation has expanded public access for education and recreation, highlighting the distinctions between shallow, artificial impoundments and natural lakes while implementing innovative, nature-based techniques for algae and aquatic plant control. Today, Duke Farms’ 11 lakes and ponds, eight of which were included in the original plan, remain central to the property’s water resources and continue to play a vital role in overall ecological health, stewardship programming, and public recreation opportunities.

Great Falls Cove at Duke Farms. Photo by Princeton Hydro Aquatic Ecologist Katie Walston-Frederick.


Evolving Strategies for an Evolving Landscape

The original Lake Management Plan integrated routine water quality monitoring, hydrologic and pollutant-load modeling, adaptive aquatic plant management, and targeted interventions to restore ecological balance. Key components included invasive species control, such as Common Carp removal to support native fish populations, and a comprehensive algae and aquatic plant program that included aeration and aquascaping. This multifaceted approach established the foundation for long-term recovery across the lake system.

As Duke Farms expanded public access and strengthened its educational mission, management strategies evolved to emphasize innovative, low-impact techniques for shallow, human-made impoundments. Recent advancements implemented by Princeton Hydro include:

  • Floating wetland islands to create habitat, improve aesthetics, and reduce nutrient loads through plant and microbial uptake.
  • Conversion of shallow pond margins to emergent wetlands by manipulating water levels to limit nuisance algal growth.
  • Design and maintenance of 11 submerged aeration systems, nine powered by solar energy in off-grid locations.
[caption id="attachment_18917" align="aligncenter" width="1227"] The photo above shows the aeration system actively circulating water in Otter Lake.[/caption]  

The most recent plan update incorporates techniques that were unavailable when the original plan was developed:

  • Duckweed skimming, a mechanical method that creates controlled currents to collect floating vegetation, opening surface water, and improving aesthetics without chemical treatments.
  • Biochar has been installed in various locations to reduce nutrient concentrations. For example, at Mermaid Pool, which is a key connector between the Reservoir and adjacent waterbodies, biochar trials show promising results in improving clarity and reducing nutrients.
[gallery columns="2" link="none" size="medium" ids="18916,18911"] These initiatives reinforce Duke Farms’ commitment to piloting forward-looking, sustainable ecosystem management practices that can guide stewardship of water resources across the region and beyond.
Hydrology Study: Reducing Pumping, Improving Water Quality

In 2012, Princeton Hydro conducted a detailed hydrologic analysis of Duke Farms’ interconnected lake system to evaluate water management strategies. Historically, water from the Raritan River was pumped into the lakes to maintain water levels. While reliable, this practice introduced elevated nutrients and sediments in the property’s lakes and ponds, degrading water quality and fueling nuisance algal blooms.

The study synthesized pump and discharge records, long-term climate and hydrologic data, and monthly water budgets, and included experimental pumping scenarios to assess alternatives. Results were transformative: under normal conditions, supplemental pumping could be reduced by more than 95%, and even during drought, by about 70%, without compromising lake levels. Based on these findings, Duke Farms adopted a low-volume, seasonal pumping strategy and transitioned to a higher-quality groundwater source, which significantly reduced nutrient loading, improved water clarity, and lowered energy consumption.

[caption id="attachment_18910" align="aligncenter" width="1227"] The Duke Farms Reservoir[/caption]

Ongoing monitoring remains a cornerstone of the Duke Farms–Princeton Hydro partnership. For each waterbody, the team conducts in-situ data collection, laboratory analyses, visual and observational evaluations, and detailed reporting. Data from continuous monitoring demonstrates sustained improvements in dissolved oxygen, water quality, and overall lake/pond health. This continuous feedback loop informs adaptive management decisions and allows Duke Farms to measure the ecological success of its restoration efforts.

We are proud to partner with Duke Farms in advancing the health and resilience of its water resources, a commitment that not only protects the lakes and ponds on the property but also delivers positive ecological benefits throughout the Raritan River watershed. Click here to learn more about our lake management work in the region. To explore Duke Farms, plan a visit to its beautiful property, sign up for educational programs, or discover ways to get involved in its conservation initiatives, visit Duke Farms’ website.

*All photos used in this blog were captured by Princeton Hydro Aquatic Ecologist Katie Walston-Frederick. [post_title] => Two Decades of Lake Management Innovation at Duke Farms [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => two-decades-of-lake-management-innovation-at-duke-farms [to_ping] => [pinged] => [post_modified] => 2025-12-12 16:52:48 [post_modified_gmt] => 2025-12-12 16:52:48 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18909 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [comment_count] => 0 [current_comment] => -1 [found_posts] => 30 [max_num_pages] => 3 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => 1 [is_tag] => [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_favicon] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => 71c7b800f958c3adc270d2de230e1413 [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:96ab938af9d137b27c87b84d5f265b73 )

Category: Lake and Pond Management

archive
 
Topics
Select Topics