GREEN LAKE WETLAND HABITAT RESTORATION PROJECT

Tufel Pond Frog Sanctuary | Creating habitat for wildlife and keeping Green Lake clean

Special Thanks to our Project Partners and Financial Supporters, including: Green Seattle Partnership, University of Washington Restoration Ecology Network Capstone Program, EarthCorps, Herrera Environmental Consultants, Joel Tufel family

Project Description

In 2025, Friends of Green Lake (FOGL) restored the South Willows Wetland and enhanced an existing wetland pond to create an amphibian oasis. For Phase 1 in early 2025, FOGL and Green Seattle Partnership collaborated with the University of Washington Restoration Ecology Capstone team of 6 students to assess the quality of existing wetland habitat, prepare a plant to restore functions of the 1.2-acre wetland, and implement the plan by removing invasive weeds and planting native plants.

Prior to the restoration, the wetland had a seasonal shallow pond, which was less than 6 inches deep during high lake levels in the winter, and had very few native plants. For Phase 2 during low lake levels in October 2025, FOGL worked with EarthCorps to deepen the pond by hand to a maximum depth of 2 feet, following the existing footprint to maintain its natural shape.

The surface 8 inches of organic soil was donated to gardeners, and the underlying clay was used to build a berm along the lake shore to keep the predatory fish out of the pond. Two gravel trenches were installed in the berm to enhance water exchange between the pond and lake. A temporary wood snow fence was installed to reduce human and dog disturbance of the pond while plants and amphibians become established.

With assistance from volunteer naturalists, we planted the pond edges and surrounding area with native sedges, rushes, grasses, shrubs, and trees selected specifically to help support frogs and other amphibians, as well as birds and pollinators. In total, we installed over 500 native plants representing 32 species, all adapted to forested wetland and woodland-edge conditions. The Tufel Pond Frog Sanctuary is named after Joel Tufel, who regularly walked the lake and who’s family member funded most of the project.

Frog and Wetland Benefits

Pacific Chorus (Tree) Frogs and many other Washington native amphibians are on the decline and need our help. Because frogs are very sensitive to changes in water quality, pollution, and habitat disturbance, they are also considered an indicator species – their presence is an indicator of a healthy ecosystem. They are considered a keystone species because they play a vital role in maintaining the balance of their ecosystems through their dual role as both predators and prey:

  • As predators, they control insect populations.
  • As prey, they are a crucial food source for birds, mammals, fish and reptiles.

Green Lake is a natural, glacier-carved lake where the water level was lowered by 7 feet in 1911 and the shoreline was diked and filled to create 100 acres of park land. Historically, its shoreline included many shallow, marshy areas dense with native sedges and rushes. These plants provide the thin, submerged stems that female frogs prefer for attaching their egg masses. The marshy edges also supported a rich mix of flowering plants that attracted insects for adult frogs to eat. Pacific Chorus Frogs and other amphibians require seasonal shallow ponds (vernal pools) that dry up in the summer and do not support predatory fish.

Most of the fish species residing in Green Lake have been introduced by the Washington Department of Fish and Wildlife, including trout stocking to support one of the best trout fisheries in Western Washington (15,000 catchable trout in 2015). However, invasive common (European) carp is the largest fish population in the lake (75 percent of fish biomass in 2003). The introduced and invasive fish in the lake eat amphibian eggs, tadpoles, and adults. Over time, shoreline and fish modifications have eliminated vernal pools and suitable amphibian habitat in Green Lake, and frog populations have disappeared from areas where they once thrived.

Although the main body of Green Lake today is not ideal habitat for most amphibians, we hope Tufel Pond provides a sanctuary where frogs and other wetland wildlife can thrive alongside the lake.

Project Goals

  • Create a “frog sanctuary” to support Pacific Chorus Frogs and other native amphibians
  • Improve habitat for birds, pollinators and other wildlife
  • Demonstrate native plantings that thrive under a tree canopy
  • Provide educational signage so park visitors can learn about wetlands, frogs, and native plants

In the Works

  • Planning and design of educational signage is currently in process.
  • Continued amphibian monitoring, plant maintenance, invasive species management, and volunteer work parties

Completed

  • 2023 – conceptualization and site evaluation
  • Jan-June 2024 initial amphibian monitoring
  • July 2024 – initiated permitting process
  • Sept 2024-June 2025 UW-REN capstone wetland restoration project
  • Oct 2025 – pond excavation and berm/fence construction in three days
  • Nov 2025 – native plantings

FAQs

Where is the frog pond located?
Tufel Pond is located at the south end of the lake, east of the Aqua Theater bleachers and dock.

Can I see frogs here now?
Amphibian populations take time to establish. We began monitoring in 2024 and will continue to track frog activity over the next several years. In early spring, you may be able to hear Pacific Chorus Frogs calling at dusk and after dark.

How does this project help keep Green Lake clean?
Wetlands act as natural filters. The plants and soils around Tufel Pond help slow and absorb stormwater, trapping sediment and some pollutants before they reach the lake.

How can I help?
You can volunteer at planting and maintenance work parties, support native habitat in your own yard or neighborhood, and avoid using pesticides and fertilizers that can wash into local waterways. You can help support this project and future projects with a financial donation to Friends of Green Lake.

What questions do you have?
Please email us your questions to friendsofgreenlake@gmail.com. We will be updating this page to address questions soon.

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