Linn County, IA Environmental Rules: Stormwater Management (2026)
Key Facts
- SWPPP trigger
- Major subdivisions & NPDES Phase II activity
- SWCD review
- Within 30 days of submittal
- Sediment removal
- At least every 5 years
- County inspection
- Construction, year one, then every 5 years
- County-owned facilities
- Maintained by the county annually
Summary
Unincorporated Linn County requires a stormwater pollution prevention plan for major subdivisions and any county-permitted land-disturbing activity that triggers NPDES Phase II, reviewed by the Soil and Water Conservation District before permits issue.
Stormwater. To limit the impact of stormwater runoff, and accompanying sediment, heat, pollutants, and energy, certain development or clearing activities will be required to complete and implement a stormwater pollution prevention plan (SWPPP). Activities requiring a SWPPP. All applicants for major subdivisions, and applicants for all other the county permits or approvals that will result in land disturbance activity that meets NPDES Phase II or later requirements shall submit to the county a SWPPP and shall implement the plan.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 16).
Full Breakdown
The county's environmental regulations require a SWPPP for major subdivisions and any other county permit or approval involving land disturbance that meets NPDES Phase II standards. The Soil and Water Conservation District reviews each plan and reports to the planning and development department within 30 days. No building permit, subdivision approval or land-disturbance permit is issued until that review is complete. Private stormwater facilities need a maintenance plan, and settled sediment must be removed at least every five years; the county inspects private facilities during construction, in their first year, and at least every five years after that, and maintains county-owned facilities annually.
Violations & Fines
Building, subdivision and land-disturbance permits are withheld until SWCD review is complete; failing to implement an approved SWPPP is a county infraction under § 107-160, enforced under chapter 1, article II.
Frequently Asked Questions
Does building in unincorporated Linn County require a stormwater plan?
Who maintains stormwater detention ponds in the county?
Sources & Official References
Other rules in Linn County
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