Planning commission recommends city council adopt new retaining‑wall rules after extended debate

The Planning Commission voted 4–2 to send a draft ordinance to the City Council that would add comprehensive retaining‑wall rules to Herriman’s municipal code, including definitions, permitting thresholds, height limits, location restrictions, and engineering and inspection requirements. Planning staff presented the draft amendment, explaining that state law already bars municipal permitting for unbalanced retaining walls under 4 feet with no external surcharge; the staff draft codifies that threshold and adds local rules. The amendment would: define ‘‘retaining wall,’’ ‘‘subdivision wall’’ and ‘‘surcharge;’’ require permits and engineering for walls with an unbalanced load greater than 4 feet or with external surcharges; restrict placement of walls near public rights‑of‑way and within 5 feet of interior lot lines (unless an exception is approved); set residential lift limits (single wall lifts up to 10 feet on interior lots, 4 feet facing the street; rockeries up to 9 feet; terrace walls up to 18 feet when meeting spacing rules); require guardrails where a drop would create a safety hazard; and require that subdivision walls be engineered, include aesthetic treatments for walls ≥9 feet, and be constructed during subdivision development where feasible. Staff said engineering would have discretion to grant exceptions for constrained topography, vehicle access needs or where terracing would eliminate usable lot area; those exceptions would require findings and engineer review. The draft also spells out submittal requirements, special inspection, and ongoing maintenance responsibilities for property owners. Commissioners debated the draft at length. Concerns included the breadth of the exception language, the financial cost of engineered walls versus rockeries for homeowners, and whether the city should require developers to install subdivision walls earlier in the subdivision process. Several commissioners asked staff to tighten the exception language so developers could not routinely claim ‘‘loss of usable space’’ to avoid terracing. Staff agreed to revise language clarifying the criteria and potentially to require commission review for certain exceptions. Commissioner Jackson moved to recommend council approval with staff refinements (noting the measurement method for heights and the exception language) and additional clarifying edits; the motion passed 4–2 on roll call. Commissioners Heather and Brody voted no, primarily because they preferred a larger minimum separation and different distance metrics. Staff will bring refined ordinance language to the council for first reading.