Sioux City, IA Environmental Rules: Stormwater Management (2026)
Key Facts
- Trigger
- 5,000+ sq ft impervious surface
- Governing chapter
- Municipal Code Ch. 12.16
- Administered by
- Utilities Department
- Permit needed
- Storm water plan + review fee
Summary
Sioux City requires storm water management review for construction creating 5,000 or more square feet of impervious surface, administered by the Utilities Department under Municipal Code Chapter 12.16.
To prevent the adverse impacts of storm water runoff, the utilities department has developed a set of performance standards that must be met at new development sites. These standards apply to any construction activity creating 5,000 or more square feet of impervious surface. The following activities may be exempt from these storm water performance criteria:
1. Any logging or agricultural activity which is consistent with an approved soil conservation plan or a timber management plan prepared or approved by the Soil and Water Conservation District, as applicable;
https://online.encodeplus.com/regs/siouxcity-ia/doc-viewer.aspx#secid-963 420/1110 8/12/26, 3:47 PM Document Viewer | Municipal Code
2. Additions or modifications to existing single-family structures;
3. Developments that do not create more than 5,000 square feet of impervious surface, provided they are not part
of a larger common development plan;
4. Repairs to any storm water treatment practice deemed necessary by the city engineer.
When a site development plan is submitted that qualifies as a redevelopment project as defined in section
Full Breakdown
Chapter 12.16 of the Sioux City Municipal Code sets storm water performance standards for subdivision and site plan applications. Section 12.16.030 applies the chapter citywide, exempting small single-family additions and land disturbance under 5,000 square feet outside a larger common development plan. Above that threshold, Section 12.16.070 requires a grading/land-disturbance permit, and Section 12.16.080 requires a storm water management concept plan, a maintenance agreement, and a non-refundable permit review fee before the Utilities Department will consider the application.
Violations & Fines
Building or grading without the required storm water permit and plan violates Chapter 12.16; the Utilities Department can withhold occupation permits until corrections to storm water practices are made and accepted.
Frequently Asked Questions
Does a small home addition in Sioux City need a stormwater permit?
What triggers Sioux City's stormwater management requirements?
Sources & Official References
Other rules in Sioux City
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