Green Stormwater Infrastructure
Together, we can use Green Stormwater Infrastructure (GSI) to collect, slow, and treat rain once it hits the earth and becomes stormwater. This will reduce flooding, sewer overflows, and pollution entering our waterways. GSI can take many forms, from rain gardens to trees, and delivers multiple benefits to communities and cities.
What can you do with GSI?
- Build a rain garden on your property through the RainWise Program
- Build a small rain garden (PDF) or bioretention system (PDF) in the planter strip yourself (for bioretention that manages stormwater from a larger area, check out Regional Voluntary Bioretention in the Right-of-Way)
- Plant a tree!
- Learn how to maintain GSI in your neighborhood (PDF)
- Learn more about GSI:
- GSI Progress Report (2021) (PDF)
- GSI Progress Report (2020) (PDF)
- GSI Progress Report (2019) (PDF)
- GSI Progress Report (2018) (PDF)
What is SPU doing with GSI?
- Partnering with property owners to offer rebates for rain garden and cistern installations through the RainWise Program, delivered jointly with King County
- Partnering with community, schools, peer City departments, and the private sector to weave GSI into the built environment
- Building and maintaining GSI capital projects to keep Puget Sound clean
- Enforcing the stormwater code in partnership with the Seattle Department of Construction and Inspections
GSI Benefits
- Cleans stormwater before it enters our creeks, lakes, and Puget Sound
- Reduces combined sewer overflows into our living waterways by keeping stormwater out of the system
- Reduces flooding in our neighborhoods
- Provides welcoming and colorful gathering spaces for our communities
- Improves air quality
- Stores more carbon in the ground
- Slows traffic
Types of GSI
- Rain gardens
- Rainwater reuse systems
- Bioretention (also known as Natural Drainage Systems)
- Biofiltration swales
- Trees
- Green roofs
- Permeable pavement
- stormwater ponds
- Floodable open space
- Reconnecting urban creeks to natural floodplains
Additional Resources
- Managing Stormwater on Your Site: Implementation Guide for Development Projects in Seattle
- 700milliongallons.org
- RainWise Program
- SPU's GSI Success Stories
- 12000raingardens.org
- EPA Green Infrastructure Website
- Saving Water Partnership
- GSI Design Manual
- SPU Projects
Contact Information
For additional information about Green Stormwater Infrastructure programs, please contact Tracy Tackett, Green Infrastructure Program Manager, at tracy.tackett@seattle.gov or (206) 386-0052.