Waynesville, MO Fence Regulations: Retaining Walls (2026)

Waynesville's supplemental area regulations at § 405.680 list a narrow set of site features that a lot owner can build inside a required yard, or that do not count toward covering more of a lot, without it counting against the zoning code's coverage and setback limits. A retaining wall makes that list only up to a specific height: no more than 18 inches above the grade of the ground it retains. Below that threshold, the retaining wall is treated the same as an unenclosed step or walkway, a fence, or a chimney attached to the main building.

All are exempt structures that do not count toward lot coverage and are not considered an infringement into the yard the code otherwise requires to stay open, even if the wall physically sits inside the front, side or rear setback. A wall built taller than 18 inches loses that exemption entirely and falls back under the code's ordinary yard and area rules, the same requirements that govern any other structure placed inside a required setback, which can mean the wall needs to sit outside the yard or be reviewed against the applicable district's setback standard.

The section gives the Board of Adjustment authority to modify yard requirements where a lot's odd shape or hillside grade makes literal compliance impractical, a provision that can matter for a retaining wall built to manage a graded or sloped lot. Because § 405.680 is part of Chapter 405's zoning regulations, building a retaining wall that violates the yard rules because it exceeds the 18-inch exemption is enforced under § 405.740's general zoning misdemeanor penalty.