Lenexa, KS Fence Regulations: Retaining Walls (2026)

Section 4-1-B-24-F-5-a-2 of the Lenexa Unified Development Code sets the engineering rules. Retaining walls that retain in excess of 48 inches of unbalanced fill must be designed by an engineer licensed in the State of Kansas, with stability against overturning, sliding, excessive foundation pressure, rotational failure and water uplift, and a minimum safety factor of 1.5 against sliding, overturning and rotational failure. Walls periodically or permanently inundated with water also need engineered design. Table 1 in Section 4-1-B-24-F-5-b covers height and permits. A retaining wall under 4 feet needs no permit, must sit at least 2 feet from property lines, cannot rise more than 6 inches above the retained surface, and can be masonry, stone or concrete.

A retaining wall of 4 feet or more needs a permit, is limited to 10 feet of exposed wall per tier, and needs tiers separated by at least 3 feet. The 2 foot minimum setback still applies, though the City can require more depending on design. Two height measures apply. For the engineering trigger, height runs from the bottom of the footing to the top of the wall, whatever the exposed amount. For the Table 1 limit, height runs from adjacent grade to the top of the wall.

A fence with a height between 42 inches and 72 inches must be installed directly on top of or within 18 inches of a retaining wall when the wall is within three feet of a walkway and the drop is 30 inches or more, and the Community Development Director can approve an alternative barrier such as shrubbery. Walls are prohibited in drainage easements, and easements for retaining walls must be wide enough for maintenance entirely within the easement.