Clean water solutions inspired by people and nature

In an urban environment like Seattle, every storm washes pollution from rooftops, roads, and other hard surfaces into local waterways. What can we do?

By examining how forests of the Northwest manage runoff from heavy rain, we’re learning how to design and build effective and environmentally-friendly systems within a city’s landscape that benefit human, marine, and aquatic health.

Research in the last few decades suggests that mimicking nature is an intuitive, effective way to minimize overflows of our wastewater system and prevent toxins from getting into our creeks, rivers, lakes, and Puget Sound.

We call these methods Green Stormwater Infrastructure (GSI).

King County Wastewater Treatment Division and Seattle Public Utilities are working together to bring GSI to our neighborhoods and manage rainwater runoff naturally. Our goal is to process 700 million gallons (enough water to fill over one thousand Olympic-sized swimming pools) of runoff every year with these eco-friendly methods.

Understand the Goal

What is Green Stormwater Infrastructure?

Green stormwater infrastructure mimics nature to capture, slow down, and clean runoff from storms. Unlike pipes and treatment plants that collect and clean runoff after it travels for miles, GSI uses plants, trees, soil, and engineering to reduce rainwater pollution and overflows in our drainage and sewer systems.

Learn about RainWise rebates

Rebates are available through the RainWise program for property owners in select areas with combined storm and sewer pipes.


Interested in learning more about GSI methods? Whether you are new to green stormwater infrastructure or a seasoned expert, access the latest science, technologies, and other information to implement green stormwater infrastructure.