Vacaville, CA Fence Regulations: Retaining Walls (2026)

The hillside overlay district covers Vacaville's steeper terrain, and Chapter 14.09.120 layers extra grading and wall standards on top of the underlying zoning district. Section 14.09.120.060 governs excavations and grading generally: cut slopes are limited to 2:1 (50 percent slope) unless a geologic engineer certifies a steeper cut will perform over the long term, and the corners of every cut or fill slope must be rounded to a minimum five-foot radius.

Subsection (C) specifically addresses retaining walls. Vacaville prohibits large retaining walls in a uniform plane outright: any wall of significant length must be broken into terraces with variations in plane, and must include landscaping to soften its length and screen it from view. The absolute height cap for a freestanding retaining wall in the hillside overlay is six feet, and any wall approaching that height must incorporate a three-foot recessed offset feature at least every 30 feet, or another comparable method of articulation, so the wall reads as a series of shorter segments rather than one long face.

These standards sit alongside the district's Section 14.09.120.050 ridgeline setback, which keeps any structure from breaking the skyline within 50 vertical feet of an adjoining ridgeline as viewed from a residential district, and Section 14.09.120.040, which requires geologic and soils engineering review by the City Engineer and Building Official before any hillside grading or development. A homeowner proposing a retaining wall taller than six feet, or a long uniform wall without articulation, needs design review approval before construction can proceed.