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RainWise—Private property owners can be part of the stormwater pollution solution

With every storm, rain carries pollutants off our roofs, driveways and other hard surfaces to creeks, the Duwamish River, our lakes and Puget Sound. During big storms, the sheer volume of this “stormwater” can cause sewer overflows and polluted runoff.

RainWise helps private property owners install rain gardens and cisterns to help manage the rain that falls on their roofs. In addition to stopping water pollution, these installations can add attractive landscaping, provide water for summer irrigation, and may reduce flooding. 

To find out if you qualify for rebates, see examples of rain gardens and cisterns, and learn more about how to get RainWise, check out

How to become RainWise

RainWise rebates cover most or all of the cost of installing cisterns and rain gardens on private properties in eligible combined sewer overflow basins. The average rebate has been around $4,400.

Here is how you get started:

  • The first step is to check your eligibility at
  • The next step is to find a contractor. If you can't attend one of our online Contractor Meet Ups, email us at with the subject line "Contractor Matchmaking" and we will help you find the best contractor for your needs.

You can also:

For more information, visit the 700 Million Gallons website .

RainWise, by the numbers (through spring 2021)

For more information about RainWise, please contact:

Jo Sullivan

Amelia Bahr

Visit the 700 Million Gallons website for more information or go on a RainWise virtual garden tour !

two people standing behind rainwise signage

rain garden

two people next to a cistern

woman in red coat with yellow umbrella next to rain wise garden

Learn more

Check out our library of webinars and resources at

Information in Vietnamese, Chinese and Spanish .

Download the following documents to learn more about this program.

Be RainWise flyerBe RainWise flyer

report cover for 2020 Annual Report2020 Progress Report , Green Stormwater Infrastructure

Not eligible for RainWise?

Green Stormwater Mini-Grants are available in the King County Wastewater Treatment Division service area.

Here are some other resources: GSI Western WA Resources

Janice Johnson
CSO Control Program