In 1998, a man illegally cut holes in a Tucson street curb. The result changed the law.

Tucson residents walking or driving through the Dunbar Spring neighborhood can see the legacy of a small act of rule breaking in the shade, plants and food growing along the street. What began in 1998 as one resident’s unauthorized experiment with a handsaw helped change how the city manages stormwater. Today, Tucson supports streetside rainwater harvesting, offers homeowners financial incentives to install it and requires water harvesting in certain new development and road projects.

Brad Lancaster cut six openings into the curb outside his home, creating channels that redirected rainwater from the street into planted areas between the roadway and sidewalk. At the time, residents were not allowed to modify public curbs without city approval. Lancaster worked quietly, according to the account of the project, sometimes early on Sunday mornings. City officials did not know about the cuts for about three years. Lancaster eventually told them because the results had become too striking to keep private.

Lancaster lived in the Dunbar Spring neighborhood just north of downtown Tucson and wanted to capture runoff for food producing trees and native desert plants. Instead of allowing rain to flow along concrete gutters toward storm drains, the openings sent it into basins designed to hold water in the soil. Those basins supported mesquite trees, native shrubs and other vegetation, turning roadside space into a growing landscape rather than treating rain solely as a drainage problem.

The change was visible over time. Trees fed by runoff developed into a shaded canopy, while neighboring residents began creating similar curbside basins. The resulting landscape is not a conventional orchard, but it includes plants with edible flowers, fruit producing cactuses and seeds that can be used as food. The system also cools the area. An account from the University of Arizona’s Water Resources Research Center found that soil in shaded, rain fed basins was noticeably cooler than soil exposed beside nearby pavement.

That cooling matters in a city where summer heat affects nearly everyone who spends time outdoors. The water harvesting features can provide shade, support habitat and reduce the need for treated drinking water to irrigate plants. They can also improve water quality and reduce nuisance flooding, according to the University of Arizona account. Lancaster’s model uses a series of basins that capture and pass along runoff, allowing one rainfall event to benefit multiple planted areas instead of disappearing quickly into the drainage system.

Tucson receives roughly 11 inches of rain in an average year, making water especially valuable in the Sonoran Desert. The city gets about 90 percent of its drinking water from underground aquifers and the Colorado River, but rainfall still offers an important local resource. Using it where it falls can help landscapes survive without relying entirely on treated municipal water. The practice also reflects much older knowledge. Indigenous people have lived in the Sonoran Desert since time immemorial, and ancestral communities used canals, earthworks and other methods to direct water and hold it in the soil for plants.

As Lancaster’s work became known, the city did not simply order the curb cuts removed. Officials began working toward policies that would make rainwater harvesting legal and repeatable. Tucson eventually established Storm to Shade, a municipal program focused on harvesting rainwater and growing trees. The program formalized techniques that residents and community groups had developed over many years. Blue Baldwin, a Storm to Shade program manager, has described the city’s effort as an institutional version of Lancaster’s pioneering work, including standardized construction details that tell contractors how to create curb openings.

The city also created a rebate of up to $2,000 for homeowners who install streetside rainwater harvesting basins. New commercial properties and road construction are required to incorporate rainwater harvesting, while city ordinance records describe a requirement that new commercial development meet at least half of its landscaping water needs with harvested rainwater instead of treated municipal supplies. Storm to Shade was later approved to install and maintain green stormwater infrastructure on public land throughout Tucson.

The policy shift did not happen because of one curb cut alone. It followed years of observation, neighborhood participation and growing recognition that small interventions could produce several public benefits at once. Lancaster’s original project demonstrated that runoff could help create cooler streets, shade, food, habitat and healthier soil. For Dunbar Spring residents, the experiment changed the character of their neighborhood. For Tucson, it offered a practical response to heat and water scarcity that could be built into city rules.

The story remains relevant as Tucson and other desert communities face drought, rising water demand and increasingly intense heat. Lancaster’s experiment did not create the idea of harvesting rainwater, which has deep roots in desert societies. It showed how those principles could be adapted to a modern city street, then tested in public view. A handful of illegal curb openings eventually became a city supported approach to stormwater management, demonstrating that a neighborhood scale project can influence public policy when its results are impossible to overlook.