RAINWISE

RainWise Rebate Increase

RainWise adjusts rebates to account for fiscal inflation and the changing climate, increasing the maximum rebates for rain gardens and cisterns. Learn more and view side-by-side examples of projects that show the difference in rebate amounts available before and after the rebate increase.

Please contact rainwise@seattle.gov with any questions.

How Are RainWise Rebates Changing?

Before 2023, the average rebate for rain gardens was $4.00 per square foot, and for cisterns, it was $3.50. Since then, rebates have increased each year.

As of April 2026, RainWise rebates are at an all-time high! Rain garden rebates are at $13.12 per square foot, and cistern rebates increased to $7.57 per square foot. This makes it the best time EVER to undertake a RainWise project!

How Are RainWise Rebates Calculated?

RainWise rebates are calculated by multiplying the roof area your installation captures by the type of system(s) installed. Rebate caps are higher for rain gardens since they do not have water storage limitations. Also, rebate rates are based on how well your system manages your stormwater runoff (i.e., larger cisterns that control more runoff will receive higher rebates.)

Merica’s Rain Garden Project

Merica’s project captured 922 sq ft of rooftop into a 70 sq ft rain garden. She received a rebate of $3,688 for her installation. Today, that same project would receive $12,097!

Julie’s Cistern Project

Julie’s project captured 1463 sq ft of her rooftop into two, linked 205-gallon cisterns. She received a rebate of $4,155 for her installation. Today, that same project would receive $8,749!

Julie’s Cistern Project – Alternative Scenarios

Julie’s project captured 1463 sq ft of her rooftop into two linked 205-gallon cisterns. Today, if she instead installed three linked 205-gallon cisterns (scenario #1), she would receive a rebate of $4,155! If she chose two linked 420-gallon tanks (scenario #2), she would receive $13,118!