Rain Garden (Bioretention): A shallow, vegetated surface depression that collects rainwater from a road, sidewalk, or parking lot and allows it to soak into the ground. 

Bioswale: Vegetated channel designed to slow, redirect, and filter stormwater runoff using soil, stones, and vegetation. 

 Curb Cut: Gap in curb that directs runoff into an area where it can be stored, infiltrated, and absorbed by vegetation.

Curb Extension (Chicanes or Bump-outs): Traffic-calming devices that extend the curb into the roadway to capture runoff from roadways and the sidewalk. 

Permeable Pavement: Paving systems (pavers, pervious concrete, porous asphalt) that allows stormwater to filter through, reducing runoff and minimizing water pollution.

In our desert ecosystem, GSI provides a responsible way to expand Tempe's tree canopy, since the harvesting and use of rainwater can reduce the amount of potable water needed to sustain vegetation. This means that trees and other vegetation can be planted without putting additional stress on Arizona's limited water supply. Growing more trees and vegetation provides shade and additional cooling benefits, helping to create a more comfortable environment in neighborhoods, parks, and along roads and multi-use paths.

Native plants are often the best choice for use in GSI installations, as they are uniquely adapted to grow in the local soil and climate conditions, provide the best habitat for native wildlife, and tend to require less water than non-native plants.

 Pictured: Native, low-water-use plants growing in a bioretention area on a median at Mill Avenue and 13th Street in Tempe, AZ. 

The Rain to Roots Master Plan will develop a comprehensive strategy for implementing, maintaining, and funding green infrastructure to promote equitable urban cooling throughout Tempe.

The project will develop a vision of a cool, resilient city, which will incorporate data on heat vulnerability and feedback from community members who have historically been underrepresented in city urban planning processes. This plan will involve...

•  An assessment of the City of Tempe's current stormwater management, urban forestry, and water conservation initiatives.  

• Recommendations for GSI project locations and the improvement of stormwater management practices.

• Pilot project designs that demonstrate how GSI can be used in streetscapes, multi-use paths, parks, and neighborhoods.

• An update of Tempe's Urban Forestry Master Plan.

• A study to identify alternative strategies to fund green infrastructure into the future. 

Beginning in September 2023, Tempe residents will have the opportunity to shape the Rain to Roots Master Plan by participating in the Rain to Roots Ambassador Program. Community ambassadors will provide feedback throughout the planning process and the development of green stormwater infrastructure (GSI) pilot projects. Participants will also learn about the city's stormwater management, urban forestry, and sustainability initiatives.

Participants will meet monthly throughout the development of the Rain to Roots Master Plan, which will be completed in the fall of 2024. However, participation in the program is flexible -- participants are not required to attend every session, and new members are welcome to join at any time. 

Program sessions will take place on the first Wednesday of each month, from 5:30 - 6:30 PM. Meetings will be hybrid, with the option to join either in-person in the Sano Room of the Escalante Multi-Generational Center (2150 E Orange St., Tempe, AZ 85281) or online via Microsoft Teams. Click here to join via Microsoft Teams.

If you are interested in participating in the program, please fill out this interest form so that the Sustainability and Resilience Office can contact you with additional information. If you have any questions about the Ambassador Program, please contact Helene Tack at Helene_Tack@Tempe.gov.  

U.S. Environmental Protection Agency - Green Infrastructure Page

Greater Phoenix Metro Green Infrastructure Handbook 

City of Tucson's GSI Maintenance Guide 

Arizona Municipal Water Users Association (AMWUA) - Sustainable Plant Database