Showing ordinances that apply to Ajo, AZ
Ajo is an unincorporated community (population 3,039) in Pima County, Arizona. Because Ajo is not an incorporated city, it does not have its own municipal code. Instead, Pima County ordinances apply directly to properties here. The stormwater management rules below are the ones that govern your area.
Pima County enforces stormwater management through the Pima County Regional Flood Control District (RFCD) and the county MS4 permit under the Clean Water Act. The Sonoran Desert monsoon season (July-September) drives strict drainage and retention requirements. All new development must retain the first inch of stormwater on-site per county standards.
The Pima County Regional Flood Control District administers stormwater regulations for unincorporated areas. Under the county MS4 (Municipal Separate Storm Sewer System) permit issued by ADEQ, all construction sites disturbing one acre or more must file an Arizona Pollutant Discharge Elimination System (AZPDES) Notice of Intent and implement a Stormwater Pollution Prevention Plan (SWPPP). The county requires on-site retention of the first inch of rainfall (the 100-year, 2-hour storm standard) for new developments. Green infrastructure practices including bioswales, retention basins, and permeable paving are encouraged. The county participates in the National Flood Insurance Program (NFIP) and maintains detailed floodplain maps through RFCD. Monsoon flash flooding is the primary stormwater concern, with arroyos and washes subject to strict no-build buffers. Contact RFCD at 520-724-4600.
Failure to implement required stormwater controls may result in stop-work orders, permit revocation, and fines up to $10,000 per day under AZPDES. Illicit discharges to storm drains are prohibited and subject to both county code enforcement and state ADEQ penalties. Report stormwater pollution to the RFCD hotline.
See how Ajo's stormwater management rules stack up against other locations.
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