Contra Costa County, CA Environmental Rules: Erosion Control (2026)
Key Facts
- Cut slope trigger
- Over 5 feet in height
- Fill slope trigger
- Over 3 feet in height
- Enforcing agency
- County Building Inspection Department
- Planting timing
- Installed after rough grading
- Final approval standard
- Growth must be established
- Variance requires
- Soil engineer or geologist recommendation
Summary
Contra Costa County's grading ordinance requires erosion protection on any cut slope over five feet or fill slope over three feet before a grading permit closes out. The county building inspection department requires planting with grass or ground cover suited to the site's soil and climate, installed after rough grading, with final sign-off withheld until growth is established on the slope.
The surface of all erodible cut slopes more than five feet in height and fill slopes more than three feet in height shall be protected against erosion by planting with grass or ground cover plants. The plants and planting methods shall be suitable for the soil and climatic conditions of the site and in accordance with standard specifications on file in the county building inspection department... The planting shall be installed after rough grading. Final approval of the work shall be made when growth is established on the slopes... Variations from the regulations in Sections 716-8.802-716-8.806 may be allowed by the building official if they will provide equivalent safety, stability, and protection against erosion, as recommended by a soil engineer or engineering geologist.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Ordinance Code: Supplement 103).
Full Breakdown
8 of the county's Grading Ordinance (Division 716) governs erosion control planting on unincorporated land. 802 requires that erodible cut slopes taller than five feet and fill slopes taller than three feet be planted with grass or ground cover plants suited to the site's soil and climate, following standard specifications kept on file with the county building inspection department. 804, planting must go in after rough grading is complete, and the county building official will not give final approval on the work until growth is actually established on the slope, not merely seeded.
806, but it must be recommended in writing by a soil engineer or engineering geologist and approved by the building official; there is no automatic exemption. 612, which requires ongoing maintenance of drainage facilities during and after the work. 1008. These duties attach to any grading permit issued under Division 716 and are checked by county inspectors before the permit is closed.
Violations & Fines
If the county building official issues a written stop-work notice under Section 716-4.1432, the permittee must immediately cause all grading and hauling to cease until written permission to resume is granted, after correcting the erosion or drainage problem that triggered the notice. Under Section 716-6.016, a contractor who stops work before completion must still leave the site safe and free of erosion, landslide, or drainage hazards to adjoining property and public roads.
Frequently Asked Questions
Does every graded lot in unincorporated Contra Costa County need erosion planting?
When does the county sign off on erosion planting?
Can I skip the required planting if I use a different erosion method?
What happens if the county issues a stop-work order over erosion problems?
Sources & Official References
Other rules in Contra Costa County
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