Retaining Walls: Fontana vs Rialto
How do retaining walls rules compare between Fontana, CA and Rialto, CA?
Fontana and Rialto have similar restriction levels.
Fontana, CA
San Bernardino County
Retaining walls in Fontana require a building permit once they retain more than 4 feet of soil measured from the bottom of the footing, or at any height if they support a surcharge. Structural plans, drainage design, and geotechnical review are often required.
View full Fontana rules →Rialto, CA
San Bernardino County
Retaining walls in Rialto are governed by California Building Code §105.2 (adopted via Rialto Code Title 15) and zoning standards in §18.61.170. Any retaining wall over 4 feet measured from bottom of footing to top of wall, or any wall supporting a surcharge, requires a building permit.
View full Rialto rules →Key Facts Comparison
| Fact | Fontana | Rialto |
|---|---|---|
| Permit Threshold | Retains over 4 ft or with surcharge | Over 4 ft (footing to top) or any wall with surcharge |
| Plans | Stamped structural calcs | - |
| Geotech | Often required over 4 ft | - |
| Drainage | Weep holes or French drain required | - |
| Combined Height | Counts toward fence height | - |
| Code Authority | - | CBC §105.2 (CCR Title 24) via Rialto Code Title 15 |
| Zoning | - | Rialto Code §18.61.170 height standards |
| Building & Safety | - | 150 S Palm Ave; 909-820-2505 |
| Boundary Walls | - | Cal. Civ. Code §841 cost-sharing applies |
Highlighted rows indicate differences between cities.
Fontana FAQ
Do I need a permit for a 3-foot rockery?
If it retains 3 feet of soil with no surcharge, likely no structural permit, but still follow setback and drainage rules.
My wall failed after rain. What now?
Document the failure and contact Building and Safety. Repair plans may need engineering review, especially if there is slope above.
Rialto FAQ
Do I need a permit for a 3-foot retaining wall in Rialto?
Generally no, if it does not support a surcharge (vehicle load or sloped soil). California Building Code §105.2 exempts walls 4 feet or less without surcharge.
What if my retaining wall holds up a driveway?
Any retaining wall supporting a surcharge (including a driveway or parked vehicle load) requires a building permit per CBC §105.2, regardless of height. Contact Rialto Building & Safety at 909-820-2505.
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