Iron County, UT Fence Regulations: Retaining Walls (2026)

Because Iron County sits on soils prone to volumetric change, collapse, and land subsidence, Section 15.06.030(D)(1) folds retaining walls into the same geotechnical review that applies to any structural appurtenance and to concrete or paved surfaces. The report behind the retaining wall design has to be no more than three years old, and it must apply the soil and foundation requirements of the International Building Code and International Residential Code, both adopted county-wide under Chapter 15.08. If a geotechnical engineer already produced a report for the parcel and it addresses the retaining wall being proposed, the same engineer reviews it for adequacy rather than starting over, and only writes a new report or supplement if the old one falls short.

The engineer's report has to identify a buildable area sized for the intended use and disclose any geologic hazard, including surface-fault ruptures, landslide or slope instability, and land subsidence, that a typical site investigation would turn up. Section 15.06.030(D)(2)(a) then closes the loop on enforcement: no final inspection can be approved, no certificate of occupancy issued, and no performance bond released until the geotechnical engineer certifies in writing that the completed retaining wall conforms to the report's recommendations and that all required inspections were made and approved.

This geotechnical step runs alongside, not instead of, the ordinary building permit process in Chapter 15.04, so a retaining wall still needs its own permit application before construction starts in unincorporated Iron County.