Walworth County, WI Fence Regulations: Retaining Walls (2026)

Sec. 26-71 of the Walworth County Code regulates retaining wall and terrace construction wherever the County Zoning Division has jurisdiction under Chapter 74. Only the minimum excavation needed to stabilize the natural slope is authorized, and any retaining wall built for slope stabilization taller than four feet must be designed and certified by a professional engineer licensed in Wisconsin, unless the landowner uses a pre-engineered product installed to the manufacturer's specifications. The ordinance also caps how steep a newly created slope can be: no change in topography may create a slope steeper than three feet horizontal to one foot vertical.

Walls proposed inside the shoreyard setback face a higher bar. Sec. 26-71(a)(5) only authorizes a new retaining wall or terrace there if the landowner proves, through an engineering report, that a current erosion problem exists that can't be fixed by re-sloping and re-vegetating the bank or by other methods consistent with natural shoreline aesthetics. When a shoreyard wall is authorized, Sec. 26-71(a)(6) requires it be shielded from the water with a diversity of native vegetation wherever site conditions allow.

Before construction, building or replacing a wall requires a construction site erosion and sediment control permit from the Land Conservation Division under Sec. 26-72, plus a retaining wall construction plan and, for shoreyard walls, the engineer's report described in Sec. 26-72(c): a slope failure analysis, the cause of the failure or reason for replacement, consideration of re-sloping and re-vegetation alternatives, and detailed construction drawings.