Alameda County, CA Environmental Rules: Erosion Control (2026)
Key Facts
- Rainy-season grading
- Restricted, needs director approval
- Plan trigger
- Over 10,000 sq ft sloped land
- Enforcing agency
- Director of Public Works
- Coverage
- Unincorporated areas only
Summary
Grading operations in unincorporated Alameda County must follow erosion and sediment control standards under § 15.36.600, including limits on rainy-season work and required long-term stabilization of disturbed slopes.
The following shall apply to the control of erosion and sediment from grading operations: A. Grading plans shall be designed with long-term erosion and sediment control as a primary consideration. B. No grading operations shall be conducted during the rainy season except upon a clear demonstration, to the satisfaction of the director of public works, that at no stage of the work will there be any substantial risk of increased sediment discharge from the site.
Full Breakdown
Alameda County Code § 15.36.600 requires grading plans in the unincorporated county to treat long-term erosion and sediment control as a primary design element. No grading may occur during the rainy season unless the applicant demonstrates to the Director of Public Works that no stage of the work risks increased sediment discharge, and the director can require detailed erosion and sediment control plans covering each construction stage. Natural vegetation and watercourses must be preserved where possible, exposed erodible ground must be minimized, and permanent erosion controls must go in as soon as grading ends. This governs unincorporated communities like Castro Valley and San Lorenzo; incorporated cities such as Oakland and Berkeley enforce their own stormwater rules.
Violations & Fines
Erosion-control violations fall under the same Chapter 15.36 enforcement scheme as unpermitted grading: misdemeanor charges or administrative fines starting at $250, escalating to $1,000 per day for continuing violations (§ 15.36.674, § 15.36.676).
Frequently Asked Questions
When is an erosion and sediment control plan required?
Can grading happen during the rainy season?
Sources & Official References
Other rules in Alameda County
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