St. Louis County, MN Environmental Rules: Stormwater Management (2026)

Section 6.19, Stormwater Management Administrative Standards, is a general Article VI standard, so under Section 6.1.A.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. When a project disturbs ground, the ordinance requires the work to minimize the area to be modified, control runoff velocity and reduce and/or delay runoff volume, keep sediment on site, and stabilize the disturbed area within seven days of completion of permitted activity, the same seven-day clock used for erosion control under Section 6.16.

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. Because this section sits in Article VI's administrative standards rather than the conditional-use chapters, meeting these four items is what keeps a stormwater plan out of the discretionary permit track; a project that cannot hold impervious coverage under the zone district maximum, or that alters natural drainage features, is pushed into the county's conditional use or variance review under Section 6.1.A.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.