Planting the Rain for Humans and Birds

Improving Tucson’s Green Stormwater Infrastructure

By Martina Car 

Green stormwater infrastructure outside Tucson Audubon's offices at the Historic Y.

As we enjoy the refreshing spring weather, it is sometimes easy to forget that Tucson is the third fastest warming city in the US. But come the scalding summer months, most Tucsonans will be eager to stay indoors, cooled by air conditioning. That time of year makes us appreciate the role of trees in providing shade and making our city more livable. But trees do so much more than just provide shade! They are the overstory that nourishes a vibrant ecosystem for insects, birds, and the wider local food chain. They create healthy soil able to sustain a variety of understory plants, including wildflowers and shrubs. Here in Tucson, trees are considered critical elements of the city’s Green Stormwater Infrastructure (GSI), which captures rainwater, reduces flooding, and helps filter out pollutants from the waterways.

Have you seen curbsides, roundabouts, or boulevard strips filled with native plants? Then you’ve probably come across GSI. What makes these structures stand out is that they include an inlet and an outlet, either in the form of a curb cut or an area where the curb is flush with the street, providing a kind of channel for water to flow through. During heavy rainstorms, water enters these structures and infiltrates the soil, where plant roots soak it up. In this way, rather than being wasted as runoff, stormwater is used to sustain urban pockets of native vegetation that benefits pollinators, birds, and humans.

Planting rain in newly installed neighborhood traffic circle. Photo: Brad Lancaster

Thanks to a new initiative approved by the Mayor and City Council in 2019, we now have public funding to support a Storm to Shade program to manage this very valuable infrastructure, and Tucson Audubon is proud to be a part of this exciting project! The Storm to Shade program is funded through a small fee on our water utility bill, which averages out to $1 per month for the typical Tucson household. These funds are then allocated for new projects using a Tree Equity Score (TES) tool that uses tree canopy and surface temperature data, as well as demographic information, to help identify and prioritize areas that will benefit most from green stormwater infrastructure.

Since the fall of 2022, our Urban Habitats Restoration Team has been working hard to make sure that GSI structures are functional and ready for our next rainy season. Field crews are shoveling out sediment, trimming overgrown trees, pulling out invasive weeds, picking up trash, and recording the condition of individual basins into the city’s mapping software.

Planting native food plants in traffic circle. Photo: Brad Lancaster

If you see us working in your neighborhood, please come say hi and have a chat! We are eager to tell you more about the importance of harvesting rainwater in our desert ecosystem and what you can do to provide valuable habitat for local wildlife. Our crew members love to nerd out on native plant knowledge and are eager to share it with you!

Our field crew supervisor, Rodd Lancaster, is one of the original implementers of rainwater harvesting in the Dunbar/Spring neighborhood, where he helped his brother Brad Lancaster and local residents “plant the rain.” Thanks to their efforts which began in 1996 and continue to this day, Dunbar/Spring was transformed from a largely barren, heat-island of a neighborhood to a lush urban forest that birds like the Wilson’s Warbler can use as a food-rich stopover along their migration path. Back in the day, cutting curbs to create water channels was illegal, but thanks to the efforts of Brad and other activists, the city of Tucson has now legalized this practice and adopted it for many of its own GSI basins. The Storm to Shade program is a great step towards greening our neighborhoods and we are excited to be a part of this effort.

Harvesting from now-grown native food plants in traffic circle. Photo: Brad Lancaster

We hope this blog sparked your interest and inspires you to learn more about what you can do to support native habitat in your area!

Additional resources:

• tucsonaudubon.org/habitat-resources
• climateaction.tucsonaz.gov/pages/gsi
• dunbarspringneighborhoodforesters.org
• watershedmg.org

Martina Car is a member of the Tucson Audubon Field Crew