Freshwater

Streams, ponds, wetlands, and marshes are the lifeblood of Vashon’s ecosystems and are a major focus of our work. The islands are an EPA-designated sole-source aquifer. This means that our aquifer is filled only from rain that falls on the islands. 

In addition to being our only source of drinking water, Vashon’s rain-fed aquifer also feeds island streams that support salmon, trout, sculpin, and more. Vashon Nature Center runs a variety of community science projects monitoring the health of local watersheds. We share our findings with conservation practitioners to promote the health of this crucial island resource.

Featured Projects

Stream Bugs and Stormwater: Our annual stream invertebrate monitoring survey is our longest running community science program. Each fall, adult and student volunteers join us in the field to sample stream bugs in our creeks. From these samples we can generate a Benthic Index of Biotic Integrity (B-IBI) score to help us gauge the health of our creeks. Every year, McMurray sixth-grade science students help us sort and count invertebrates collected in Shinglemill Creek to determine the B-IBI score. Read more about the results in our Stream Bug Stories report on our publications page.

SalmonWatchers and Trout Trackers: In 2016, Vashon Nature Center began coordinating a long-running program launched by King County that enlists volunteers to count and identify salmon returning to spawn in local creeks. Data are available from 2001 through the present, giving us a useful record of local spawning trends. We recruit new SalmonWatchers every fall. Our Trout Trackers program, started in 2024, begins every February and organizes volunteers to monitor returning sea-run cutthroat trout. Read the Trout Tracker 2024 Report and the 2025 SalmonWatcher Year End Summary to see our most recent data. 

Get Involved

Our Fantastic Partners

Thank you to the following partners and supporters of our stream and watershed work: Vashon-Maury Island Groundwater Protection Committee (our founding and longest supporters of watershed programs), King County Flood Control District, King County Waterworks,, Rose Foundation, The Russell Family Foundation, Keta Legacy Foundation, Vashon-Maury Island Land Trust, Vashon Parks District, Puyallup Tribe Fisheries, Coastal Cutthroat Trout Coalition, Washington Department of Fish and Wildlife.