Retaining Wall & Block Wall Rules in St. George (2026)

Updated October 10, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Rule	What it says	Source
Retaining wall permit	Required for retaining walls 4 ft or taller, unless shown in detail on an approved site plan. Application includes a site plan and a landscape and drainage plan.	St. George Code 10-18-5
How height is measured	Concrete and block walls: top of footing to top of wall. Rockery and segmental block: exposed face to finished grade.	10-18-5
Front setback	Any fence or retaining wall needs a permit. Retaining walls up to 4 ft, none in the first 10 ft behind the sidewalk. Fences up to 4 ft, decorative only within 10 ft of the sidewalk.	10-18-1, 10-18-2, 10-18-5
Side and rear fences	Up to 6 ft 4 in. Nothing over 3 ft in the sight triangle at intersections. Berms can't be used to gain height.	10-18-1
Max single wall	10 ft for residential retaining walls. Taller grade changes must be terraced with landscaped benches at least half as wide as the tallest wall is high.	10-18-2
Wall plus fence	No more than 15 ft of exposed face on side, rear or interior lot lines.	10-18-2
Near buildings and pools	Any retaining wall within 10 ft of a structure, including accessory buildings and pools, needs a site-specific geotechnical report.	10-18-2
Safety railing	Walls over 6 ft within 5 ft of a hillside, sidewalk, trail or wash.	10-18-2
Tiered rockery or segmental walls	Treated as one wall unless the horizontal gap is more than 1.5 times the height of the taller wall. Design by a geotechnical engineer.	10-18A-6, 10-18A-7
Contractor license	Most wall work over the handyman exemption (currently under $7,000 per project, labor and materials) needs a Utah contractor license.	Utah Code 58-55-305

Is a block privacy wall the same as a retaining wall?

Not in the code, and not structurally. A privacy wall (the code calls it a fence) on level ground is limited mainly by height and location. A retaining wall holds back soil and falls under the retaining wall rules, including the 4-foot permit threshold. When a privacy wall sits on top of a retaining wall, the combined face is capped at 15 feet on side and rear lines, and the retaining part has to be designed for the extra load.

Why is the buried part of the wall counted?

For concrete and block walls, St. George measures height from the top of the footing, not from the ground you see. A wall that shows 3 feet 6 inches above grade with a course or two below ground can measure over 4 feet. If you're close, ask the building department before you build.

What does the city want in an engineered wall submittal?

For walls that need engineering, the city asks for the wall type, the loads on it (such as driveways or structures above), how it drains, soil and groundwater information, and any utilities within 8 feet of the wall. Your builder or engineer prepares this.

Which soil hazards affect walls in the St. George area?

The Utah Geological Survey's hazard study of the St. George–Hurricane area maps several conditions that matter for wall footings:

Collapsible soils. Common in young alluvial-fan and debris-flow deposits. They can settle up to about 10 percent of their thickness when wetted for the first time, often by irrigation.
Expansive soil and rock. Clay-rich shale, claystone and mudstone that swell when wet and crack slabs and walls.
Gypsum-bearing soils. Where gypsum is plentiful it can dissolve and cause settlement or sinkholes, and its sulfate attacks concrete, so sulfate-resistant (Type V) cement is typically required.
Rockfall. The most common slope failure in the area. Cuts for building pads can make it worse.
Blowsand and shallow bedrock. Wind-blown sand is widespread, and bedrock is often within 10 feet of the surface.

UGS recommends site-specific geotechnical work where these conditions exist. For any significant retaining wall, ask whether a soils report is needed.

How does the weather affect walls here?

St. George averages a July high of about 102°F and roughly 9 inches of rain a year, so walls spend most of their life dry. The trouble comes when water arrives fast. Summer monsoon storms can bring sudden flash flooding, as in July 2012 when up to 2 feet of water ran through some St. George streets. In January 2005, about 12 inches of rain in 48 hours sent the Santa Clara River through Santa Clara and St. George, destroying more than 28 homes. Drainage behind retaining walls, and grading that keeps runoff off the top of a wall, matter more than the yearly rainfall suggests.

Which contractor license covers wall work in Utah?

S330 Landscape and Recreation covers retaining walls, except walls that hold back vehicles, structures, equipment or non-natural fill close to the wall.
S230 Masonry, Siding and Stucco covers brick, block and concrete block work.
B100 General Building contractors can perform most specialty work.

Projects under $7,000 in combined labor and materials can fall under Utah's handyman exemption. Check any license on the Utah Division of Professional Licensing (DOPL) licensee lookup before you sign.

Do HOAs add their own rules?

Often. Many Washington County subdivisions have architectural guidelines that require committee approval for walls and set colors, materials and heights. Some limit retaining walls to 4 feet without approval and may require tiering. HOA approval doesn't replace a city permit, and a city permit doesn't replace HOA approval.

What about Washington, Hurricane, Ivins and Santa Clara?

Each city has its own code and building department, and their thresholds can differ from St. George's. Properties outside city limits fall under Washington County. Confirm with the office that covers your address before you build.

Common questions

How tall can a retaining wall be without a permit in St. George?

Under 4 feet, measured from the top of the footing for concrete and block walls, unless the wall is in a front setback, where any wall needs a permit.

How tall can a block fence be in St. George?

Up to 6 feet 4 inches in side and rear yards and 4 feet in the front setback, with a 3-foot limit in sight triangles at intersections.

What license does a retaining wall contractor need in Utah?

Usually S330 Landscape and Recreation for retaining walls, S230 for block masonry, or a B100 General Building license. Small jobs under the handyman exemption, currently under $7,000, are an exception.

Retaining wall and block wall rules in St. George (2026)