Douglas County, CO Fence Regulations: Retaining Walls (2026)

Douglas County Zoning Resolution § 1-715(1) sets a four-foot threshold for retaining walls, lower than the six-foot trigger that applies to an ordinary fence or wall, because a retaining wall holds back soil and carries a structural load the county's Building Code addresses directly; crossing four feet in height requires a building permit reviewed by the Douglas County Building Division against that code, not just the zoning height limit. Below four feet, a retaining wall can be built without a county permit, but § 1-715 still requires it to sit outside the public right-of-way and, if it stands within the setback that faces a street, keep to the four-foot solid-fence height ceiling that applies there as well.

Once built, § 1-715(5) makes upkeep the landowner's ongoing legal responsibility: the section requires every fence, wall, or hedge, retaining walls included, to be maintained in good structural condition, and puts the duty to repair or remove a failing wall squarely on the property owner whenever poor maintenance, dilapidation, obsolescence, or abandonment turns it into a safety hazard or a zoning violation. A wall built without the required permit, or left to deteriorate into a hazard, is enforced the same way as any other Zoning Resolution violation, through the notice-and-penalty process in §§ 1-113 through 1-115, and a homeowner seeking relief from the four-foot standard for a taller wall on a difficult lot can request an administrative adjustment or Board of Adjustment variance under §§ 1-2602 and 1-2604.