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?

What is SPU doing with GSI?

  • Building and maintaining GSI projects through our capital program to keep Puget Sound clean
  • Collaborating with the Seattle Department of Construction and Inspections to enforce the Stormwater Code to ensure stormwater best management practices when parcels are redeveloped.
  • Developing partnerships that help weave GSI into the built environment. More information about these programs will be provided when available:
    • RainWise is a City of Seattle and King County rebate program that helps eligible private property owners manage stormwater by installing cisterns and rain gardens.
    • RainCity Partnerships Program partners with eligible multi-family, commercial, and industrial private property owners in selected neighborhoods to build voluntary green infrastructure projects and restore riparian areas to improve water quality and habitat waters.
    • Beyond Code Partnerships support developer projects that have Stormwater Code minimum requirements and would benefit from a more holistic approach to stormwater management that can achieve greater impact above and beyond code requirements.

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

Contact Information

For additional information about Green Stormwater Infrastructure programs, please contact Tracy Tackett, Green Infrastructure Program Manager, at or (206) 386-0052.

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000

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Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.