Mendocino County, CA Fence Regulations: Retaining Walls (2026)

Sec. 020(B) of the Mendocino County Code sets a hard limit on how a tall slope can be retained: any embankment over six feet in height has to be benched so that no individual retaining wall in the series exceeds 48 inches above finished grade, and each bench has to be at least as wide as the height of the wall it supports. The code's own figure, captioned "Retaining Wall Step Design Illustration," spells out the point in plain terms directly beneath the diagram: retaining walls more than six feet high have to be stepped the way the illustration shows, rather than built as one continuous face.

152-A if it is visible from the yard above. Because the section does not carve out an engineering-review exception, a single 10-foot retaining wall built without stepping does not comply even if it is structurally sound; the benching requirement is a zoning standard, not just a safety recommendation, and Planning and Building Services checks for it independently of the county's building-permit structural review.