Iron County, UT Environmental Rules: Stormwater Management (2026)

Iron County folds stormwater and drainage control into Chapter 15.12's flood hazard reduction standards rather than running a separate stormwater ordinance. Section 15.12.160(D) requires every subdivision proposal to be consistent with minimizing flood damage and, specifically under Section 15.12.160(D)(3), to provide adequate drainage to reduce the subdivision's exposure to flood damage. For any subdivision proposal or other development containing at least fifty lots or five acres, whichever is less, Section 15.12.160(D)(4) requires base flood elevation data to be submitted with the application so the drainage design can be checked against it.

Section 15.12.160(E) then caps the cumulative effect of new development: combined with everything else already built or anticipated, a project cannot raise the base flood's water surface elevation by more than one foot at any point. Beyond the subdivision context, general stormwater discharges are addressed only through the wastewater rules in Chapter 13.08, which bars stormwater, surface water, and swimming pool drainage from entering the county's sewer system without the general manager's specific authorization. There is no separate stormwater utility, fee, or standalone drainage permit in the code; drainage adequacy is reviewed as part of the subdivision approval and flood development permit process administered by the commission chairman.