St. Louis County, MN Environmental Rules: Stormwater Management (2026)
Key Facts
- Scope
- Applies countywide to all uses/structures
- Coverage cap
- Impervious coverage capped at zone district max
- Stabilization deadline
- Disturbed area stabilized within 7 days
- Facility review
- Engineered stormwater facilities need Director approval
- Enforcement
- Section 8.2; misdemeanor after 30-day notice
Summary
Countywide, Section 6.19 of Zoning Ordinance 62 lets stormwater management proceed without a separate permit only if a property stays under the zone district's maximum impervious lot coverage, leaves natural drainage features unchanged, retains sediment on site during any disturbance, and restabilizes disturbed ground within seven days; engineered stormwater facilities still need Director review and approval.
Section 6.19 Stormwater Management Administrative Standards "C" A. No Permit Required: General Minimum Standards for All Stormwater Management: No permit shall be required for stormwater management if the following standards are met: 1. Impervious lot coverage shall not exceed the maximum lot coverage of the zone district. 2. Existing natural features that control stormwater runoff shall remain unchanged. 3. When areas are to be disturbed, alterations shall be managed to minimize the area to be modified, control runoff velocity and reduce and/or delay runoff volume. Sediments shall be retained on site and the disturbed area shall be stabilized within seven days of completion of permitted activity. 4. Constructed facilities used for storm water management shall be reviewed by a qualified professional and approved by the Director.
Full Breakdown
1 it applies to "all uses or structures" in unincorporated St. Louis County, not just shoreland parcels. Subsection A sets the no-permit path: impervious lot coverage cannot exceed the maximum already set for the zone district, and existing natural features that control stormwater runoff shall remain unchanged. 16. Any constructed stormwater facility, meaning a pond, swale, or other engineered control rather than natural drainage, must be reviewed by a qualified professional and approved by the Director before it counts toward compliance. 2 instead of being handled administratively.
The Planning and Zoning Department checks these standards at the same time it reviews the underlying land use permit for the structure or alteration generating the runoff.
Violations & Fines
Exceeding the zone district's impervious coverage cap, altering natural drainage features, or installing an unapproved stormwater facility is a Section 6.19 standards violation, pursued through the county's Section 8.2 enforcement process. The Director can order the property owner to correct the drainage or coverage problem, and failure to comply within a reasonable time gets referred to the County Attorney, with conviction a misdemeanor and fines paid to the county's general revenue fund.
Frequently Asked Questions
Does St. Louis County require a stormwater permit for every project?
Who approves an engineered stormwater pond or swale in the county?
What happens if a project changes natural drainage on my property?
Sources & Official References
Other rules in St. Louis County
Compare St. Louis County to another location·View the Minnesota environmental rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.