Casa Grande, AZ Environmental Rules: Stormwater Management (2026)

Casa Grande Municipal Code Chapter 18.08 bars discharging or causing to be discharged into the municipal storm drain system or watercourses any materials, including pollutants, that cause or contribute to a violation of water quality standards (§ 18.08.060(A)). Illicit connections to the storm drain system, including ones made in the past, are separately prohibited under § 18.08.060(C). Exempted discharges include water-line flushing, landscape irrigation, diverted stream flows, rising groundwater, foundation drains, air conditioning condensation, non-commercial vehicle washing, and firefighting activity (§ 18.08.060(B)). The Public Works Director or a designee administers and enforces the chapter (§ 18.08.030), can suspend MS4 access without notice during an emergency discharge, and may terminate access for repeated illicit discharges (§ 18.08.070).

Enforcement begins with a written notice of violation that can order monitoring, cessation of discharges, remediation, and payment of a fine covering administrative and remediation costs (§ 18.08.130). A recipient has fourteen days to appeal, with a hearing set within fifteen days of the appeal (§ 18.08.140); uncorrected violations authorize the city to abate the condition and assess the property owner for costs, which become a lien if unpaid (§§ 18.08.150-.160). Violations are also declared a public nuisance and may draw injunctive relief (§§ 18.08.170, .190).