Corona, CA Fence Regulations: Retaining Walls (2026)

Corona Municipal Code Section 105.1.3, added by Ordinance 3421 to the adopted Building Code, requires a building permit before anyone erects, alters or repairs a retaining wall over two feet in height measured from the top of the footing, and for walls of any height that support a surcharge or superimposed load other than natural level fill. Section 105.2, the exempt-work amendment, mirrors that line: retaining walls two feet or under, measured footing-top to wall-top, need no permit unless they carry a surcharge or hold back Class I, II or IIIA liquids.

Design standards sit in Chapter 15.36, the city's grading chapter. Section 15.36.250 splits retaining walls into two tracks. Walls built as part of a grading plan must be reinforced concrete, reinforced masonry block, reinforced concrete block, geosynthetic fabric, or a combination, engineered to resist every earth pressure and surcharge load acting on them, designed by a registered civil or structural engineer, and submitted to the Public Works Department with structural calculations and top-of-wall/top-of-footing elevations shown on the grading plans before installation. Walls not tied to a grading plan skip Public Works and instead go to the Building Department, still with a registered engineer's structural calculations for review and approval.

Section 15.36.220's Table B-1 also lets a retaining wall substitute for a slope setback, but only if the City Engineer approves the substitution and, per its Note 3, the maximum height for a developer-initiated wall is four feet unless the Planning Department approves otherwise; walls above six feet get case-by-case City Engineer review.