Rainwater harvesting, a practice supported through of Pima Association of Governments’ Stormwater Program, captures or slows down surface stormwater so that it can be put to beneficial use.

When we harvest rainwater, we can use it to irrigate surrounding vegetation to help beautify the landscape and increase shade without depending on groundwater.

Rainwater harvesting practices can be active or passive. Active rainwater harvesting uses gutters and downspouts to direct water into cisterns that store water for future use. Passive rainwater harvesting uses depressions and/or berms called "earthworks" to store water in the soil, where it can be used by vegetation.

• Broad-based implementation of rainwater harvesting could reduce municipal water demand by reducing the need for potable water for irrigation, which accounts for over a third of household water use in Tucson.
• Rainwater harvesting also prevents water from running into the streets, where it can pick up pollutants that are then transported into washes.
• Broad-scale rainwater harvesting could result in decreased floodwaters and reduced erosion near culverts and other flood control devices in drainage areas.
• Incorporating rainwater techniques into residential landscapes has the potential to increase property values by meeting LEED green building requirements.
• Rainwater harvesting is key to building urban green infrastructure. Storing water in the soil for vegetation provides a cascade of effects such as providing habitat, reducing the urban heat island effect, cooling and shading urban neighborhoods and improving air quality. Such stormwater management that mimics natural processes and maintains natural functions is known as Low Impact Development (LID).