Flagstaff, AZ Environmental Rules: Stormwater Management (2026)

The City of Flagstaff created its Stormwater Management Utility, an enterprise fund, under Chapter 12-02 to manage, construct, maintain and regulate the City's stormwater drainage systems citywide, plus any area outside the corporate limits covered by an intergovernmental agreement. Section 12-02-001-0007 places the underlying duty on property: every owner and developer of real property being developed in Flagstaff must provide, manage, maintain and operate on-site stormwater systems and facilities sufficient to collect, convey, detain, control and discharge stormwater safely and consistently with City development regulations and state and federal law.

A property that fails to meet that duty is declared a nuisance, and the City may file an abatement action in court; if the court finds the nuisance and the owner does not fix it within the time the court allows, City crews may enter the property, perform the necessary work themselves, and bill the actual cost to the owner in the same manner as a stormwater service charge. City officers and employees may enter private property on reasonable notice to inspect, survey and test for compliance with any resulting court order or judgment.

The Utility funds this program, plan review and inspection through stormwater service charges set under Section 12-02-002-0003, structured so similarly situated properties pay similar rates, with credits available under the City's Credit Manual, adopted by Ordinance No. 2004-22, for property owners who maintain their own on-site detention or protective easements that reduce the City's cost of service. Separately, Section 12-01-001-0006.8(D) requires every development citywide to include stormwater storage or other mitigation for events up to the 100-year storm, and bars streets from carrying stormwater in place of washes, channels or storm drains.