University of Washington students present wildlife connectivity maps to Sammamish City

University of Washington graduate students presented a wildlife connectivity analysis to Sammamish City officials during a pre-meeting, outlining likely movement corridors for multiple species and recommending areas for protection, restoration and culvert upgrades.

The students—introduced by Professor Waller and led by Hannah Gronke—described a functional-connectivity analysis using circuit theory implemented in Omniscape. They said they combined land-cover, road layers, culvert data and a development hierarchy to assign resistance values to a raster and compute current flow; their analysis used a 30-meter base resolution and a 1–100 resistance scale. The students presented species-level outputs (cougar, beaver, Pacific giant salamander, western toad, woodpecker) and a normalized map showing the top 25% of modeled flows across species.

"This analysis focuses more on connectivity, so how does that habitat interact with the rest of Sammamish's landscape and how do animals move in between those habitat patches," Gronke said, explaining the project emphasized movement rather than habitat quality. She illustrated outputs with a Granite Falls example and city-specific maps showing bright corridors where flow is concentrated and darker patches where development reduces connectivity.

Among the findings, the team highlighted strong cougar corridors on the city’s northern edge and connections from the south linked to Cougar Mountain and the Issaquah Alps; beaver corridors aligned with stream networks; Pacific giant salamander movement depended on tree cover and natural-bottom culverts; western toads required aquatic breeding sites and terrestrial links; and woodpeckers showed strongest connectivity in forested southeast areas. The combined species map also showed significant corridors along George Davis Creek, adjacent to upzoned commercial areas.

Council participants asked several clarifying questions. One asked whether dark areas indicate impediments or concentrated movement; Gronke answered that bright yellow or red areas typically mark concentrated flows (pinch points) where surrounding landscape is hostile and animals are funneled, while dark areas generally reflect highly developed, low-connectivity zones. The presenter confirmed the team will provide zoomable, context-rich maps tied to local landmarks when the final analysis is delivered and noted the project's raster resolution is 30 meters.

Some officials raised safety and management concerns about large predators. "Do we really want to encourage cougars to travel through the middle of our city?" one council member asked, citing risks to people and pets. Gronke cautioned that modeled corridors indicate where animals are likely to move if present but are not proof of presence: "It doesn't mean necessarily that they are there," she said, and recommended combining connectivity outputs with local collaring data and additional biological study before using the maps to change management actions. Professor Waller added that using connectivity analysis to intentionally steer movements in particular directions would be a novel application requiring further research.

The students recommended riparian buffer protection, culvert upgrades (noting salamanders prefer natural-bottom culverts), and attention to corridors that occur through residential and developed areas as well as parks and stream corridors. They said bumblebee results were still pending.

Debbie, who convened the pre-meeting, thanked the student team and noted she expects copies of the final analysis. The team committed to deliver final maps and data to the city for planning use and follow-up discussion.

Next steps: the University team will finalize the analysis, provide zoomable maps and supporting documentation to Sammamish City staff, and the city will consider additional biological data and guidance before making operational management decisions based on the connectivity outputs.