Protecting Greenwood Lake’s Water Quality Through Stormwater Management

The summer is upon us and Lakes Appreciation Month is right around the corner, what better time to pay a visit to and learn more about the lakes in your area.

Princeton Hydro conducts work on lakes throughout the Northeast to preserve, protect and improve water quality and ecological health, ensuring that your community lakes can be enjoyed now and into the future. Today, we’re putting the spotlight on Greenwood Lake:

Greenwood Lake, a 7-mile-long interstate lake that straddles the border of New York and New Jersey, is a popular recreation spot for residents and tourists of both states. Considered to be one of the top bass fishing lakes in New Jersey, Greenwood Lake is abundant with largemouth and smallmouth bass, yellow perch, chain pickerel and catfish. The lake is also extensively used by residents for swimming and boating.

For over 35 years, Princeton Hydro’s scientists have worked with New Jersey, local governing municipalities, and the various environmental organizations involved with the protection of Greenwood Lake and its watershed. In the early 2000s, we developed a comprehensive Restoration Plan and a proactive monitoring program that we have used over the years to properly manage the lake and its watershed. The plan was developed for the Greenwood Lake Commission and the Township of West Milford with funding provided through the New Jersey Department of Environmental Protection’s Nonpoint Source 319(h) Program. The Restoration Plan focuses heavily on the implementation of various types of stormwater best management practices (BMPs) to help reduce the influx of sediment and nutrients into the lake. We track the positive effects and benefits achieved through these stormwater projects by conducting both storm-event based and in-lake water quality monitoring.

The goal of the stormwater-based efforts is to ensure the lake’s total phosphorus (TP) load is systematically reduced in accordance with the lake’s established Total Maximum Daily Load (TMDL). The TMDL is a regulatory term in the U.S. Clean Water Act, that identifies the maximum amount of a pollutant (in this case phosphorus) that a waterbody can receive while still meeting water quality standards. Princeton Hydro was instrumental in developing the TMDL for Greenwood Lake. Phosphorus entering the lake from runoff is the primary driver of the lake’s eutrophication. The direct results of eutrophication are increases in the density of aquatic plants and nuisance algae. All this added productivity leads to reduced clarity, reductions in dissolved oxygen concentrations, and a number of other ecological impacts that compromise the quality, aesthetics, and use of the lake.

Last year, Princeton Hydro and the Greenwood Lake Commission, with input from the West Milford Environmental Commission, proposed an updated Watershed Implementation Plan (WIP) for the lake. Approved and funded by the NJ Highlands Council, the updated WIP includes a variety of components that build upon the original Restoration Plan and incorporate newly advanced stormwater management and Nonpoint Source Pollution (NPS) reduction technologies.

Belcher's Creek at Edgecumb and Glencross

The WIP includes in‐lake and stream monitoring; the assessment of the existing stormwater structures installed through grant‐based, watershed activities; and the identification of watershed-based projects that can be completed to support the Lake’s compliance with TMDL TP levels with a specific focus on the stormwater runoff produced by Belcher’s Creek, a major tributary to Greenwood Lake.

The WIP also includes the following nine minimum elements considered necessary by both NJDEP and USEPA for funding eligibility:

  1. Identify causes and sources of pollution
  2. Estimate pollutant loading into the watershed and the expected load reductions
  3. Describe management measures that will achieve load reductions and targeted critical areas
  4. Estimate amounts of technical and financial assistance and the relevant authorities needed to implement the plan
  5. Develop an information/education component
  6. Develop a project schedule
  7. Describe the interim, measurable milestones
  8. Identify indicators to measure progress
  9. Develop a monitoring component

While many of these elements have been indirectly addressed to varying degrees in the original Restoration Plan, in order to maximize Greenwood Lake’s opportunities to obtain State and Federal funding for the design and implementation of watershed control measures, the WIP now explicitly correlates the nine elements to eight specific deliverables, which are as follows:

  1. Conduct a detailed in‐lake and watershed‐based water quality monitoring program and compare the data to that collected in 2004 and 2005 to document changes or shifts in water quality.
  2. Meet with the Township of West Milford, Passaic County and other stakeholders to
    inventory recently completed BMPs and other watershed management measures.
  3. Conduct a field‐based evaluation of the stormwater project completed since the original 319‐grant funded Restoration Plan.
  4. Conduct site assessments to identify other potential stormwater/watershed BMP projects.
  5. Conduct a field assessment of the Belchers Creek Corridor to identify potential Nonpoint Source Pollution Reduction Projects.
  6. Assemble the WIP with all the 9 elements fully satisfied.
  7. Schedule and implement stakeholder and public meetings to evaluate project status.
  8. Submit of final version of WIP to the NJDEP and present the findings and recommendations to the public.

This project was initiated in September 2018 and is projected for completion by September 2019. The Greenwood Lake Commission, serves as the inter‐State steward of the Greenwood Lake watershed, and is working closely with Princeton Hydro and the watershed stakeholders (Township of West Milford, Passaic County and others), to ensure the WIP is a holistic document.

Stay tuned for more Greenwood Lake updates as the WIP progresses. For more information about Princeton Hydro’s lake management projects and capabilities, or to discuss your project needs and goals, please contact us.

Some of the photos utilized in this blog are from The Village of Greenwood Lake.

Efforts to Manage Hydrilla in Harveys Lake Prove Difficult but Effective

Collaboration between state agencies and local organizations in Luzerne County bring in grant money to determine Hydrilla infestation levels in Harveys Lake. Treatment efforts are scheduled for 2019.

Story provided by Princeton Hydro Senior Limnologist Michael Hartshorne, and originally published in the Pennsylvania iMapInvasives Fall 2018 Newsletter

Hydrilla (Hydrilla verticillata)

Hydrilla (Hydrilla verticillata) is a relatively new invasive plant in Pennsylvania with the first documented occurrence in 1989 in Adams County. Still, it was not until recently that lake managers, park rangers, and others in the natural resource field have turned their attention to this aggressive invader. Looking incredibly similar to our native waterweed (Elodea canadensis), hydrilla differs in that it is comprised of 4-8 whorled, toothed leaves in contrast to the smooth edged, 3-leaved whorl of E. canadensis.

 

Harveys Lake, located in the Borough of Harveys Lake (Luzerne County) is a large, deep glacial lake with limited littoral (i.e., shoreline) habitat. A significant body of work has been conducted at the lake with the original Phase I: Diagnostic-Feasibility Lake study conducted in 1992 and a Total Maximum Daily Load (TMDL) issued for phosphorus in 2002.

From 2002 to present, Princeton Hydro has assisted the Borough in the restoration of the lake with a heavy focus on stormwater best management practices (BMPs) supplemented by routine, in-lake water quality monitoring. The goal of the storm water/watershed-based efforts was to reduce the lake’s existing, annual total Hydrilla (Hydrilla verticillata) phosphorus load so it’s in full compliance with the established TMDL.

Mapped locations noted in 2014 and 2015 of hydrilla in Harveys Lake as documented in the Pennsylvania iMapInvasives database.

Over the last 15 years, the installation of these watershed-based projects has led to improved water quality conditions; specifically, phosphorus and algae concentrations have been reduced. While water quality conditions improved Harveys Lake, it was during one of the routine, summer water quality monitoring events conducted in July 2014 that a dense stand of hydrilla was noted at the Pennsylvania Fish and Boat Commission’s public boat launch. More than likely, the plant entered the lake as a “hitchhiker” on the boat or trailer being launched from this public boat launch by someone visiting the lake.

Hydrilla (Hydrilla verticillata) Credit: Nick Decker, DCNR Bureau of State Parks

Since the initial identification and confirmation of the hydrilla, the Borough of Harveys Lake has worked in conjunction with the Harveys Lake Environmental Advisory Council, the Luzerne County Conservation District, the Pennsylvania Department of Environmental Protection, and Princeton Hydro to secure funding for additional surveys to determine the spatial extent and density of growth followed by an aggressive eradication plan.

Grant funds already allocated to Harveys Lake under the state’s Non-Point Source Pollution Program were used to conduct a detailed boat-based and diving aquatic plant survey of Harveys Lake to delineate the distribution and relative abundance of the hydrilla in 2014. During these surveys, the distribution of the hydrilla was found to be limited to the northern portion of the lake with the heaviest densities just off the boat launch with plants observed growing in waters 20-25 feet deep.

A follow-up survey had shown hydrilla coverage to increase from 38% of surveyed sites to 58% of sites in 2016 with hydrilla now present at the lake’s outlet area. Spatial coverage of hydrilla increased from approximately 50 acres in 2014 to 210 acres in 2016, an increase of 160 acres.

This map shows the 2018 proposed treatment area of Harvey’s Lake. Due to funding issues, treatment is now scheduled for 2019. The current hydrilla distribution encompasses the entire littoral zone of Harvey’s Lake.

In hopes of preventing hydrilla escaping into the lake’s outlet stream, the Borough of Harveys Lake funded an emergency treatment of the two-acre outlet area in 2016 utilizing the systemic herbicide Sonar® (Fluridone). A follow-up treatment of 159 acres was conducted in 2017, again utilizing the Fluridone-based systemic herbicide.

The next treatment, which will attempt to cover the majority of the littoral habitat covered by hydrilla, is scheduled for late spring/early summer of 2019. It should be noted that Sonar® is being applied at a low concentration that is effective at eradicating the hydrilla, but will not negatively impact desirable native plant species.

The treatments conducted to date have documented some reductions in the vegetative coverage of hydrilla as well as tuber production relative to the original plant surveys conducted in 2016. However, it is recognized that it will take multiple years of treatment to eradicate this nuisance plant from the lake, as well as a highly proactive, interactive program to educate residents as well as visitors to the lake in preventing the re-introduction of this or other invasive species to Harveys Lake.

 

The successful, long-term improvement of a lake or pond requires a proactive management approach that addresses the beyond simply reacting to weed and algae growth and other symptoms of eutrophication. Our staff can design and implement holistic, ecologically-sound solutions for the most difficult weed and algae challenges. Visit our website to learn more about Princeton Hydro’s lake management services: http://bit.ly/pondlake

Michael Hartshorne‘s  primary areas of expertise include lake and stream diagnostic studies, TMDL development, watershed management, and small pond management and lake restoration. He is particularly skilled in all facets of water quality characterization, from field data collection to subsequent statistical analysis, modeling, technical reporting, and the selection and implementation of best management practices. He has extensive experience in utilizing water quality data in concert with statistical and modeling packages to support load reduction allocations for the achievement of water quality standards or tailored thresholds set forth to reduce the rate of cultural eutrophication. He also has significant experience in conducting detailed macrophyte, fishery, and benthic surveys.

New York Hosts Harmful Algal Blooms Summit

Photo: Veronica Volk, Great Lakes Today

Photo credit: Veronica Volk, Great Lakes Today

The Western New York Harmful Algal Blooms (HABs) Summit, the last of four Statewide HABs summits, was held last month in Rochester, NY. The summits kicked off Governor Cuomo’s $65 million initiative to protect the NY State’s lakes, ponds and reservoirs, and those that rely on these waterbodies for recreation and drinking water, from the ecological and health impacts associated with HABs.

“Protecting New York’s natural resources is key to ensuring residents have access to safe water, and through this collaborative summit, we are addressing the growing threat of harmful algal blooms,” said Governor Cuomo in a recent press release.

Tim Schneider, Owasco Lake Watershed Inspection Program

Photo: Tim Schneider, Owasco Lake Watershed Inspection Program

Each regional summit involved a day-long session of expert presentations and panel discussions on a variety of HAB related topics, and culminated in an evening session, which was open to the public and provided community members an opportunity to learn more about the Governor’s initiative and pose questions to NYSDEC about HABs and the management of HABs. The evening sessions were available to view via a live online stream as well.

For each summit, the Governor invited regional experts to participate along with NYSDEC and Department of Health experts. The experts were brought together to initiate the development of tailored HAB action plans. Although the focus was placed on the management of Governor Cuomo’s 12 priority waterbodies, the goal was to identify HAB management plans applicable for all of the State’s waterbodies, large or small. The discussions that evolved through the four summits set the stage to inform decisions related to preventing and properly responding to HABs across the state.

Participating by the invitation of Governor Cuomo and the NYSDEC in last month’s Western New York Summit were:

  • Dr. Steve Souza, Princeton Hydro
  • Art DeGaetano, Cornell University
  • Christopher Gobler, SUNY Stony Brook
  • Dave Matthews, Upstate Freshwater Institute
  • Greg Boyer, SUNY ESF
  • Nelson Hairston, Cornell University
  • Sally Flis, The Fertilizer Institute
  • Tim Davis, Bowling Greene State University, Ohio

During the Western New York Summit, Dr. Souza, Princeton Hydro co-founder, provided insight on the causes of HABs and, in particular, discussed the management techniques that have been successfully implemented by Princeton Hydro to combat the onset and mitigate the impacts of HABs.

About Governor Cuomo’s Harmful Algal Blooms program:
Governor Cuomo’s program builds on New York’s $2.5 billion Clean Water Infrastructure Act investments in clean water infrastructure and water quality protection. The Harmful Algal Blooms initiative is supported with funds from both the Clean Water Infrastructure Act and the $300 million Environmental Protection Fund. Through the Governor’s leadership, New York has developed the most comprehensive HABs outreach and monitoring programs in the country, led by DEC sampling of ambient waters across the state and DOH sampling at regulated beaches and public water systems.

2018 NYSFOLA Annual Conference

The New York State Federation of Lake Associations (NYSFOLA) will host its 35th Annual Conference May 4-5 at the Fort William Henry Conference Center in Lake George.

This year’s conference, which is titled, “Protecting Our Lakes for 35 Years – Our Past, Present and Future,” will feature a diverse exhibitor hall, networking opportunities, a silent auction and a variety of educational sessions. Princeton Hydro is exhibiting and giving five presentations:

  • Nutrient Inactivation: A Pennsylvania Case Study by Dr. Fred Lubnow, Director of Aquatic Programs
  • You Have Your Lake Data, Now What? Creating a Watershed Plan by Chris Mikolajczyk, Senior Aquatic Scientist
  • One Watershed, Many Lakes: A Strategic Plan for the Kettle Lakes of Southern Onondaga and Northern Cortland Counties by Michael Hartshorne, Senior Limnologist
  • Proactive Management of Harmful Algal Blooms by Dr. Stephen Souza, Founder
  • Hydrilla Control in Harveys Lake, PA by Dr. Fred Lubnow

Environmental professionals, students, recreation enthusiasts, lakeside residents and community members are all invited to come together to explore a variety of topics related to managing and protecting watersheds. Additional educational session topics include, Citizen Science Water Quality Monitoring, Managing Water Chestnut and Other Invasives, Severe Weather Events Emergency Preparedness, and much more. Click here to view the complete agenda.

If you’re attending the conference, be sure to visit the Princeton Hydro booth to discuss the latest advancements in pond, lake and watershed management. If you’re interested in participating, you can register here. Registration closes on April 27th.

Stay tuned for a conference recap and photos!

ABOUT NYSFOLA
NYSFOLA was founded in 1983 by a coalition of lake associations concerned about water quality, invasive species, and other issues facing New York’s lakes. Today, more than 200 lake associations across the state are members of the only statewide voice for lakes and lake associations. NYSFOLA also has corporate members and individual members who support our efforts.

Improving Water Quality & Reducing Habitat Loss with Floating Wetland Islands

Floating Wetland Islands (FWI), also known as floating treatment wetlands, 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 that could fuel algae growth; 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. FWIs are also highly adaptable and can be sized, configured and planted to fit the needs of nearly any lakepond or reservoir.

Princeton Hydro Senior Scientist Katie Walston recently completed the Floating Island International (FII) Floating Wetland Master Seminar. The seminar provided participants with an in-depth look at the various technologies and products FII offers. Through hands-on examples, course participants learned how to utilize wetland islands for fisheries enhancement, stormwater management, shoreline preservation, wastewater treatment and more.

“The Master Seminar was truly valuable both personally and professionally,” said Katie. “I learned a tremendous amount and thoroughly enjoyed the experience. It’s very fulfilling knowing that I can take the knowledge I’ve learned back to Princeton Hydro and make positive impacts for our clients.”

FII was launched by inventor and outdoorsman Bruce Kania who was driven by the desire to reverse the decline of wetland habitats by developing a new and natural stewardship tool that could clean water and, in the process, improve life for all living creatures. He found that the answer lies in Biomimicry: duplicating nature’s processes in a sustainable, efficient and powerful way to achieve impeccable environmental stewardship for the benefit of all life.

Bruce brought together a team of engineers and plant specialists and created BioHaven® floating islands. These islands biomimic natural floating islands to create a “concentrated” wetland effect. Independent laboratory tests show removal rates far in excess of previously published data: 20 times more nitrate, 10 times more phosphate and 11 times more ammonia, using unplanted islands. They are also extremely effective at reducing total suspended solids and dissolved organic carbon in waterways.

Due to population growth, industrialization and climate change, wetlands are at risk of rapidly declining in quantity and quality due. However, every floating wetland island launched by FII provides an effective strategy for mitigating and adapting to the impacts of over development and climate change.

The unique design of BioHaven® floating islands means that 250 square feet of island translates to an acre’s worth of wetland surface area. These versatile floating islands can be launched in either shallow or deep water, and can be securely anchored or tethered to ensure that they remain in a specific location. They are almost infinitely customizable, and can be configured in a variety of ways.

In addition to ongoing prototype development, FII offers licensing opportunities to businesses and production facilities worldwide. FII continues to research and develop collaborative pilot projects to quantify BioHaven® floating islands’ efficacy.

Many thanks to Bruce and Anne Kania for hosting the Floating Wetland Master Seminar and inspiring action through their knowledge, passion and ongoing endeavors.

 

Princeton Hydro Founder Invited to Speak at EPA’s Harmful Algal Blooms Workshop

Princeton Hydro Founder Dr. Steve Souza was an invited speaker at the USEPA Region 2 Freshwater Harmful Algal Blooms (HABs) and Public Drinking Water Systems workshop last week in Manhattan. The objective of the workshop was to share information about the monitoring and assessment of freshwater HABs and the efforts to minimize their effect on public drinking water and the recreational uses of lakes.

Steve’s presentation focused on the proactive management of HABs, providing useful tips for and real-world examples of how to address HABs before they manifest, and, if a HAB does manifest, how to prevent it from further exacerbating water quality and cyanotoxin problems.

The workshop was well attended with 80 people on site and 40 others participating via webinar link. Steve was joined by nine other invited speakers, most of whom were representing the USEPA, NYSDEC and NJDEP, who gave presentations on a variety of HABs related topics, including the optimization of water treatment operations to minimize cyanotoxin risks surveillance and assessment of HABs, and communicating HABs risks in recreational lakes and drinking water reservoirs.

If you’re interested in learning more about HABs, you can view a complete copy of Steve’s presentation, titled Proactive Management of Harmful Algae Blooms in Drinking Water and Recreational Waterbodies, by clicking the image below. Please contact us anytime to discuss how Princeton Hydro’s Invasive Weed and Algae Management Services can be of service to you.

The USEPA Region 2 serves New Jersey, New York, Puerto Rico, the U.S. Virgin Islands, and eight tribal nations. Get more info on key issues and initiatives in USEPA Region 2.

 

 

Barnegat Bay Green Infrastructure Project Named “Project of the Year”

Princeton Hydro is thrilled to announce that American Littoral Society’s Barnegat Bay Green Infrastructure Project has been named “Project of the Year” by The American Society of Civil Engineers Central Jersey Branch.

The award-winning project was a collaboration between the Littoral Society, Princeton Hydro and key partners that involved implementing a variety of green infrastructure stormwater management projects in order to decrease the volume of runoff and associated pollutants flowing into and damaging Barnegat Bay.

The green infrastructure projects were designed to treat stormwater at its source while delivering environmental, social and economic benefits to the Bay. Completed projects include:

  • Conversion of standard, grassed detention basins into naturalized bio-retention basins, as exemplified by the Laurel Commons Carnation Circle Basin, which now serves as a paradigm for the cost-effective retrofitting of aged, traditional detention basins
  • At Toms River High School North, the installation of tree boxes,
  • At the Toms River Board of Education offices, the replacement of conventional paving with permeable pavement,
  • At multiple sites, the construction of rain gardens,
  • At Toms River High School North, the construction/installation of stormwater management Manufactured Treatment Devices (MTDs)
  • At the Toms River Community Medical Center (RWJ Barnabas Health), the construction of a bio-retention/infiltration basin

The entire Princeton Hydro team extends our warmest congratulations to Helen Henderson and all of the folks at American Littoral Society for winning this prestigious award! Princeton Hydro is proud to partner with this incredible organization and is grateful for the work they do to protect our beautiful coastline and save the bay!

The Awards Dinner and celebration takes place on Tuesday, October 17th at the Forsgate Country Club. The “Project of the Year” nomination was originally submitted by Princeton Hydro founder Dr. Stephen Souza on behalf of the Littoral Society.

For a more detailed summary and photos of the award-winning project, click here.

Environmental Education Opportunity

Upcoming Course Announcement:
Green Infrastructure Stormwater Management 1-Day Class

Members of the Princeton Hydro team are teaching a 1-day class on Green Infrastructure Stormwater Management Techniques at Montclair State University.

This innovative class, offered through the University’s Continuing Professional Education Services program, focuses on the proper selection, design, implementation and maintenance of green infrastructure techniques commonly used in urban and suburban settings. Multiple site examples will be provided helping participants walk away with a deeper understanding of how to apply what they learn in real-world scenarios.

The course will be held on Friday, October 6, 2017 from 8:00 AM to 4:00 PM. Advance registration is required. To sign up for and get more course details, click here.

Continuing Professional Education Services, LLC is the brainchild of Dr. Jorge H. Berkowitz and Philip I. Brilliant. From the inception of the Continuing Environmental Education for Professional (CEEP) program at the College of Science and Mathematics (CSAM) at Montclair State University, Dr. Berkowitz and Mr. Brilliant have been in the classroom and in the boardroom assuring the success of the program. In order to better serve the community of professionals, Dr. Berkowitz and Mr. Brilliant stepped forward with a solution that has saved the ability to offer continuing education credit-bearing courses at the second largest public higher education institution in New Jersey. Together they form CPES at Montclair State University!

Tracking and Managing Harmful Algae Blooms

A Presentation by Princeton Hydro Founder Dr. Stephen Souza
Available for Free Download Here

The presentation covers all things related to identifying, addressing and preventing Harmful Algae Blooms (HABs), including:

  • Understanding what defines HABs, Cyanobacteria and Cyanotoxins
  • Dispelling common misconceptions about HABs
  • Educating on the health implications associated with HABs, specifically related to drinking water and recreational water usage
  • Learning about PARETM – Princeton Hydro’s unique strategy for addressing HABs
    • (P)redict – Forecasting a bloom
    • (A)nalyze – Measuring and quantifying a bloom
    • (R)eact – Implementing measures to prevent and control a bloom
    • (E)ducate – Providing community outreach and public education

To learn more about Princeton Hydro’s Invasive Weed and Algae Management Services, visit our website or contact us!

 

Client Spotlight: Roaring Brook Lake, Putnam Valley, NY

A Comprehensive Lake Management Plan Designed by Princeton Hydro

roaring-brook-lake Since 1998, Princeton Hydro has been working with the Town of Putnam Valley, often referred to as the Town of Lakes, to restore and maintain its waterbodies. The most recent area of focus is Roaring Brook Lake, a 115-acre man-made lake surrounded by a wooded landscape community that includes 260+ homes. The lake provides a variety of recreational opportunities for boaters, anglers, swimmers and outdoor lovers and is the center point of the Roaring Brook Lake District.

The Town of Putnam Valley and the Roaring Brook Lake District hired Princeton Hydro to conduct a thorough analysis of the lake’s ecological health, identify problems affecting the quality of the lake, and develop a detailed plan to improve and protect the lake. Specifically, Princeton Hydro will implement a detailed assessment of the lake that involves water quality monitoring, bathymetric mapping (measurement of lake depth and sediment thickness), aquatic plant surveys, and quantification of the lake’s hydrologic and pollutant budgets. These data will be utilized collectively to produce a comprehensive management plan for Roaring Brook Lake and its watershed.

Water Quality Monitoring

Water quality data are used to interpret the existing chemistry of the lake, identify water quality trends, pinpoint problems and assess nutrient levels.

At Roaring Brook Lake, Princeton Hydro will specifically collect in-situ data from the surface to the bottom of the water column. The resulting temperature, dissolved oxygen, pH and conductivity data will be used in combination with laboratory generated data to assess the lake’s thermal stability and investigate the potential for internal phosphorus loading. In addition, samples will be collected to identify phytoplankton and zooplankton in the lake; some of the plankton is considered a nuisance while others are considered valuable relative to the lake’s food web.

Bathymetric Assessment

The bathymetric assessment will generate accurate lake water depth, and provide sediment thickness and distribution data for the entire body of water. These data are then used to evaluate the need for dredging, asses how and where aquatic plants become colonized and other management options that can affect long-term decisions regarding the restoration and protection of Roaring Brook Lake. The bathymetric data are also used in the various trophic models that help predict the lake’s response to incoming nutrients.

Specifically, Princeton Hydro will utilize hydrographic surveying methods to conduct the bathymetric assessment of Roaring Brook Lake. A specialized dual frequency fathometer will be used to measure water depth and the thickness of the unconsolidated sediment present throughout the lake. The fathometer is directly tied into GPS, so data are consistently collected at the exact position of the survey transects. The GPS data and accompanying water depth data will be placed into a GIS format for the generation of morphometric data and bathymetric maps of the lake.

Aquatic Plant Mapping

Aquatic plants hold sediments in place, reduce erosion and provide habitat for fish and other important wildlife and insects. Although native aquatic plants are imperative to a lake’s health, an overabundance of these plants and the presence of invasive plants can have very negative impacts.

Princeton Hydro will be conducting a complete mapping of the aquatic plant community within Roaring Brook Lake to identify the plant species present in the lake, their relative abundance and location, and provide a basis for future evaluation of changes in the plant community. This data will greatly inform lake management activities moving forward. Additionally, with this data, Princeton Hydro will be able to assess the effectiveness of the resident grass carp – currently stocked in the lake – in keeping the submerged vegetation under control.

 

Hydrologic and Pollutant Budget

The hydrologic budget represents the water balance of a lake, accounting on an annual scale for all of the inputs and losses of water. The hydrologic data is used extensively in conducting trophic state analyses and is important in determining the feasibility and utility of many in-lake restoration techniques. At Roaring Brook Lake, Princeton Hydro will investigate and quantify four key components of the hydrologic budget, including direct precipitation, overland runoff (stormwater, snowmelt, etc.), tributary inflow and groundwater seepage.

Once the hydrologic budget is complete and land-use has been categorized and quantified, a pollutant budget can then be developed. The development of a detailed pollutant budget is a critical component of any lake management plan. For the purpose of the Roaring Brook Lake study, the term pollutant refers to the nutrients nitrogen and phosphorus as well as total suspended solids. The pollutant budget represents a quantification of the input of pollutants from various sources to the lake. Because the amount of nitrogen and phosphorus present in the lake stimulates eutrophication and results in water quality impacts, proper quantification of the nutrient load is critical for the development of a site-specific and cost effective management plan.

Data Analysis

The data analysis for Roaring Brook Lake will focus on identifying an acceptable in-lake condition (i.e. specific level of algal biomass in the lake) and correlate this to the lake’s annual phosphorus load through a robust water quality model.

The data analysis will involve the review of both historical and current data and will be used to identify correlations and relationships between existing pollutant concentrations/loads and unacceptable water quality conditions (i.e. algal blooms, high rates of turbidity, nuisance densities of aquatic plants, etc.). Water quality thresholds and goals will be established for assessing the long-term progress of the lake management plan.

Lake Management Plan

roaring-brook-lake-1Properly managing your lakes and ponds starts with developing a customized management plan and involves a holistic approach to ensure continued success.

A good management plan is informed by substantial data collection and analysis (as described above); includes any necessary permit requirements and a proposed timetable for implementation; provides recommendations for priority ranking of particular activities and restoration measures; and discusses predicted benefits of the plan’s implementation and how each activity is linked to the established water quality goals. A well-crafted and thorough lake management plan will also include a review of the various Federal, State, County and local grants, programs and initiatives that may provide funding for the identified in-lake and watershed projects.

• • •

Princeton Hydro’s work with Roaring Brook Lake marks the 16th project they’ve conducted for the Town of Putnam Valley. Princeton Hydro’s proven success in watershed management stems from the cumulative training and experience of its staff, and its ability to develop watershed management solutions that are both practical and effective, which has led to the firm’s very high success rate in improving water quality.

If you’re interested in developing a customized, comprehensive management plan for your lake or pond, please contact us!