Environmental Rules in Sioux City, IA (2026)
2 verified environmental rules for Sioux City, Iowa, sourced directly from the municipal code and official government pages.
Verified from official government sources
Stormwater Management
Sioux City is a regulated Phase II MS4 community (one of 43 in Iowa) and operates under an Iowa DNR-issued NPDES Municipal Separate Storm Sewer System permit administered by the city's Environmental Services Division. The framework is anchored in Iowa Code chapter 455B (DNR jurisdiction over water quality, including section 455B.197 NPDES authority) and Iowa Administrative Code 567 chapter 60 (wastewater treatment and disposal, with stormwater rules at IAC 567-60.11). Construction sites disturbing one or more acres also need Iowa DNR General Permit No. 2.
Sioux City Stormwater Management - MS4 NPDES Program
Heavy RestrictionsFlood Zones
Sioux City regulates floodplain development under Municipal Code chapter 20.07 (Construction in Flood Hazard Areas), located within Title 20 (Buildings and Construction). The city participates in the National Flood Insurance Program and uses FEMA Flood Insurance Rate Maps for Woodbury County to identify Special Flood Hazard Areas along the Missouri River, Big Sioux River, Floyd River, and Perry Creek. The 2011, 2019, and 2024 Missouri River flood events demonstrated the city's substantial flood exposure.
Sioux City Construction in Flood Hazard Areas - Ch. 20.07
Heavy RestrictionsLooking for Woodbury County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Sioux City city rules.
Environmental Rules in Woodbury County →