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.