Wisconsin Erosion Control (2026)

Key Facts

Residential code: SPS 321.125
Site threshold: 1+ acre or per local rule
Inspection trigger: 0.5 inch rainfall
Plan required: Before grading

Full Breakdown

Construction sites disturbing one or more acres must implement best management practices under NR 151 to prevent sediment from leaving the site. One- and two-family residential construction follows Wis. Admin. Code SPS 321.125, which requires silt fences, tracking pads, inlet protection, and stabilization of disturbed soils. Operators must prepare an erosion control plan before grading and maintain BMPs until permanent vegetation is established. Inspections occur weekly and after rainfall events of 0.5 inch or more. The DNR enforces NR 151 statewide while DSPS governs residential sites; municipalities cannot waive these baselines.

Violations & Penalties

Violations may result in stop-work orders, daily forfeitures up to $10,000 under Wis. Stat. 281.98, and requirements to remediate sediment-impacted waterways and downstream property.

Frequently Asked Questions

Do I need erosion control for a single home build?

Yes. SPS 321.125 requires silt fences, tracking pads, and inlet protection on every new one- and two-family dwelling site, regardless of acreage.

Who enforces erosion control standards?

DNR enforces NR 151 for sites of one acre or more and MS4 communities. DSPS and local building inspectors enforce SPS 321 on residential sites.

How often must I inspect controls?

BMPs must be inspected at least weekly and within 24 hours after a rainfall event of 0.5 inch or greater, with damaged controls repaired promptly.

Wisconsin Construction Site Erosion Control Rules