Cupsaw Lake Welcomes New Floating Wetland Islands

Volunteers and community stakeholders gathered at Cupsaw Lake in Ringwood Township, NJ for the installation of two floating wetland islands, an innovative nature-based solution that improves water quality while enhancing biodiversity.

The project was funded by Skylands Guardian, a nonprofit organization dedicated to protecting the natural resources of New Jersey’s Highlands region through education, advocacy, and environmental stewardship. In partnership with Skylands Guardian, Princeton Hydro Aquatic Ecologist Katie Walston-Frederick led the hands-on installation event, which transformed native plants and recycled materials into living ecosystems designed to benefit the lake for years to come.

A Nature-Based Solution for Cupsaw Lake

Nestled within the Ramapo Mountains, Cupsaw Lake is a 65-acre freshwater lake in the heart of Ringwood Township. To help preserve its long-term ecological health, local partners continue to invest in innovative, science-based management initiatives. Floating wetland islands are one such solution.

Constructed from recycled materials and planted with native vegetation, floating wetland islands are designed to mimic the functions of natural wetlands. Beneath the surface, extensive root systems create habitat for beneficial microbes that help remove excess nutrients from the water column while providing shelter and foraging opportunities for fish and other wildlife. The result is a floating ecosystem that supports water quality, biodiversity, and habitat enhancement all at once.

Research has shown that a 250-square-foot floating wetland island can remove approximately 10 pounds of phosphorus annually while providing roughly the same nutrient-processing surface area as one acre of natural wetland. Considering that a single pound of phosphorus can generate up to 1,100 pounds of wet algal biomass, floating wetland islands have the potential to significantly reduce nutrient availability and help limit some of the factors that contribute to nuisance algal blooms.

A Hands-On Community Effort

A key component of the Cupsaw Lake project was community participation.

Katie coordinated and directed the installation effort, guiding volunteers through each stage of the process. Participants learned how to prepare native plants, install plant plugs within the floating island matrix, apply protective goose netting, and properly deploy and anchor the islands within the lake. The event provided an opportunity for volunteers to learn firsthand about lake ecology, nutrient management, and the role innovative restoration tools can play in protecting local water resources.

As the newly planted vegetation establishes itself in the coming months, the islands will become increasingly effective at nutrient uptake while creating a visually appealing focal point within the lake. Over time, the native plantings and submerged root systems will provide valuable habitat for fish, macroinvertebrates, and other wildlife. In addition to their environmental benefits, the islands will serve as a visible reminder of the community’s commitment to protecting and enhancing Cupsaw Lake.

Part of a Larger Watershed Vision

The project also aligns with broader watershed management efforts taking place throughout Ringwood and the New Jersey Highlands. In 2019, the Borough of Ringwood became the first municipality in New Jersey to pursue a regional approach to private lake management through a public-private partnership with four lake associations: Cupsaw, Erskine, Skyline, and Riconda.

Situated within the northeast corner of the Highlands region, Ringwood is home to numerous lakes and reservoirs that provide drinking water to millions of New Jersey residents. To support the long-term protection of these resources, the Borough partnered with Princeton Hydro to develop a comprehensive watershed management plan that identifies and prioritizes projects that address both immediate and future water quality concerns.

This approach recognizes that healthy lakes require more than in-lake management. Sustainable improvements depend on addressing nutrient and sediment sources throughout the surrounding watershed. And, organizations like Skylands Guardian play a critical role in turning watershed planning into on-the-ground action. Projects like the Cupsaw Lake floating wetland islands complement larger watershed initiatives by improving water quality, enhancing habitat, and fostering community engagement.

More About Katie

During her more than 11 years with Princeton Hydro, Katie has contributed to a wide range of water quality monitoring programs, fisheries investigations, habitat restoration projects, and watershed assessments. She serves as the firm’s primary coordinator for floating wetland island projects and has overseen installations at waterbodies throughout the Mid-Atlantic.

In 2017, she became certified as an Island Master Builder through Floating Island International, receiving specialized training in the design, construction, installation, and application of floating wetland island technology. Her expertise helped ensure that the Cupsaw Lake installation project not only achieved its technical objectives but also provided a meaningful educational experience for volunteers and community members.

Click here to learn more about Katie.

A special thank you to Skylands Guardian for documenting the installation and helping share the story of this exciting community-driven project. To learn more about the Skylands Guardian and how to support the great work they’re doing, click here.

To learn more about another one of Princeton Hydro’s long-term lake management initiative, explore our blog, Two Decades of Lake Management Innovation at Duke Farms, which highlights efforts to protect and monitor the interconnected lakes and ponds across Duke Farms’ 2,700-acre property in Hillsborough, New Jersey.

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