Sahuarita, AZ Environmental Rules: Stormwater Management (2026)

The Sahuarita stormwater management program addresses the intense monsoon rainfall characteristic of southern Arizona. Individual storms can deliver 1 to 3 inches of rain in under an hour, generating massive runoff volumes on desert soils with low infiltration capacity. New development must include stormwater retention and drainage plans that prevent post-development runoff from exceeding pre-development levels. On-site retention basins or dry wells are commonly required to capture the first flush of stormwater and allow it to infiltrate. Grading plans must direct drainage away from structures and toward approved drainage facilities without impacting neighboring properties. The Pima County Regional Flood Control District has regulatory authority over major watercourses and drainage infrastructure. Development near regulated washes requires floodplain use permits and must not reduce flood conveyance capacity. Low-impact development techniques including pervious paving, bioswales, and rainwater harvesting are encouraged. Existing property owners must maintain their drainage systems and cannot modify grading in ways that redirect water onto neighboring lots. Monsoon season from July through September is the primary period of concern, though winter storms can also produce significant runoff.