Costa Mesa, CA Environmental Rules: Erosion Control (2026)
Key Facts
- Adopted code
- Orange County Grading and Excavation Code, Article 8
- Conflict rule
- More restrictive of county code or CBC Appendix J governs
- Minor fill exemption
- Under 1 ft deep, 20 cubic yards or less, slope 5:1 max
- Planter fill exemption
- Under 3 ft deep, 20 cubic yards or less
- Still required
- Compaction report even for exempt fills
- Enforcing official
- Building official / development services director
- Violation class
- Misdemeanor, separate offense each day
Summary
Costa Mesa requires grading and excavation work to comply with the Orange County Grading and Excavation Code, adopted under Municipal Code Section 5-1.4, in addition to Appendix J of the 2025 California Building Code, with the more restrictive of the two controlling. Only minor fills under specific volume and depth limits are exempt, and even those still need a compaction report.
Article 8 of Title 7, Division 1 of the Codified Ordinances of the County of Orange, including the Grading Manual, is adopted in its entirety, except that section 7-1-805(i) and 7-1-805(l) are modified as follows: Section 7-1-805(i). A fill less than one (1) foot in depth which: (1) is placed on a natural grade with a slope less steep than five horizontal to one vertical (5:1); (2) does not exceed twenty (20) cubic yards on any one lot; and (3) does not obstruct a drainage course. This does not exempt the project proponent from submitting a compaction report, to the Building Official, for review and approval, on the fill placed.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4894290; v9 updated 2025-11-18).
Full Breakdown
1 incorporates Article 8 of Title 7, Division 1 of the county's Codified Ordinances, including the county Grading Manual, in its entirety, with two local modifications. Under the modified Section 7-1-805(i), a fill under one foot deep is exempt from a grading permit only if it sits on a natural grade no steeper than five horizontal to one vertical, does not exceed twenty cubic yards on any one lot, and does not obstruct a drainage course, but the property owner must still submit a compaction report to the building official for review and approval.
The modified Section 7-1-805(l) applies the same twenty-cubic-yard and drainage-course limits to landscape planter fills up to three feet deep. Section 5-1 separately requires that where the county grading code and Appendix J of the California Building Code differ, the more restrictive provision governs erosion, sediment, and drainage control on a project. The building official administers grading permits and compaction report review, and, as with every other adopted code, the California Code of Regulations and State Building Standards Code control over any conflicting local grading amendment. Project applicants file grading plans with the building official as part of the same permit submittal used for the underlying construction project.
Violations & Fines
Grading or excavation work performed without the required permit, or in violation of the adopted county code's erosion and drainage control standards, is unlawful under Section 5-6 and constitutes a misdemeanor, with each day of continued violation a separate offense. The development services director's deputies can cite violations as a misdemeanor or infraction under Section 1-33.1, and the city attorney can pursue civil or criminal abatement, recovering costs and attorney's fees from the responsible property owner once a notice and order is final.
Frequently Asked Questions
What erosion and grading code applies in Costa Mesa?
Is a small fill exempt from a Costa Mesa grading permit?
Does a landscape planter fill need a grading permit?
What if I grade without a permit in Costa Mesa?
Sources & Official References
Other rules in Costa Mesa
California rules heatmap·Compare Costa Mesa to another location·View the California environmental rules overview
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How other cities in Orange County handle erosion control.