Walworth County, WI Environmental Rules: Erosion Control (2026)

Walworth County's Construction Site Erosion and Sediment Control Ordinance, Chapter 26, Article II, was adopted under Wis. Stats. §§ 59.693, 59.70, 92.07(15) and 236.45, plus § 101.1206 for public buildings and places of employment, and is administered by the Walworth County Land Conservation Division. Sec. 26-35(b) triggers the permit requirement at several thresholds: grading, clearing or other land-disturbing activity affecting 4,000 square feet; excavation or filling of 400 cubic yards or more; construction of public or private streets, driveways, airstrips or bridges; disturbance of 300 or more linear feet of an underground pipe, utility or open channel; and any land-disturbing activity within 1,000 feet of a lake or 300 feet of a navigable waterway, which reaches even a one- or two-family dwelling built that close to water.

Exemptions cover routine plowing, planting and harvesting, private on-site wastewater system installation under Chapter 70, work by a state or federal agency within its own project boundaries, and construction of a one- or two-family home outside shoreland and floodplain areas that disturbs less than an acre, which instead falls under Chapter 26, Article III. A landowner applies to the Land Conservation Division with an erosion and sediment control plan and fee; Sec. 26-63 gives the Division 30 days to approve or request more information. Sec. 26-65 requires the landowner to notify the Division within 48 hours of starting and finishing work, inspect controls within 24 hours of any half-inch rain and at least weekly, and keep the approved plan on site.

Retaining walls and pond construction regulated under the county's shoreland zoning code, Chapter 74, also need an erosion-control permit under this article before work starts.