Sonoma, CA Fence Regulations: Retaining Walls (2026)
Key Facts
- Standard maximum height
- 6 feet from finished grade
- City planner discretionary increase
- Up to 1 additional foot
- Safety fence on top of wall
- Up to 42 inches, any wall height
- Fill-wall setback rule
- 1 foot setback per 1 foot of height
- Governing section
- SMC 19.46.040
Summary
Retaining walls in the City of Sonoma cannot exceed 6 feet measured from finished grade, though the city planner can approve up to 1 extra foot for topography. A safety fence up to 42 inches can top any retaining wall regardless of the wall's own height.
A. Maximum Height – Six Feet. Retaining walls shall not exceed a height of six feet measured from the finished grade at the base of the wall. The city planner may approve additional height up to one foot in consideration of varying topographical features. B. Fence or Wall Topping. 1. Wall for a Cut in Grade. Where a retaining wall protects a cut below the finished grade and is located on a front, side, or rear property line, the retaining wall may be topped by a fence or wall of the same height that would otherwise be allowed if no retaining wall existed. ... ... 3. Safety Protection. Regardless of the height of the retaining wall, an open-work, non-view-obscuring fence may be erected at the top of the retaining wall for safety protection to a maximum height of 42 inches.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 13-2025, passed December 3, 2025).
Full Breakdown
040, Height limitations for retaining walls (current through Ordinance 13-2025, December 3, 2025), caps retaining walls in the City of Sonoma at 6 feet measured from the finished grade at the base of the wall, with the city planner authorized to approve up to 1 additional foot in consideration of varying topographical features. 040(B)(1) allows it to be topped by a fence or wall of the same height that would otherwise be allowed on that property line if no retaining wall existed. 040(B)(2) counts the retaining wall's own height toward the allowable height of any fence or wall built on top of it, so the two heights are added together against the district's normal fence-height cap.
040(B)(3) always allows an open-work, non-view-obscuring safety fence at the top of a retaining wall, capped at 42 inches. 110, the wall or fence must be set back from the retaining wall one foot for every one foot of height, and the strip between the two must be landscaped and kept in good condition. 030, which expressly defers to this section for retaining walls.
Violations & Fines
A retaining wall built over the 6-foot cap (or the city planner's approved 7-foot maximum) without approval is enforced under the City of Sonoma's development-code enforcement chapter: SMC 19.90.040(A) declares a noncompliant structure a public nuisance, and SMC 19.90.040(B) makes violating any development-code provision a misdemeanor. The city planner can issue a stop-work order on construction in violation under SMC 19.90.040(C), and violating that stop-work order is itself a separate misdemeanor.
Frequently Asked Questions
How tall can a retaining wall be in the City of Sonoma without special approval?
Can I put a fence on top of my retaining wall in Sonoma?
Does a retaining wall count toward my property's fence height limit?
Sources & Official References
Other rules in Sonoma
California rules heatmap·Compare Sonoma to another location·View the California fence regulations overview
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Retaining Walls in Nearby Cities
How other cities in Sonoma County handle retaining walls.