Yolo County, CA Environmental Rules: Erosion Control (2026)
Key Facts
- Governing section
- Sec. 10-9.303(a)
- Trigger
- Construction activity under a building permit
- Large-site threshold
- Disturbance over 1 acre needs SWPPP
- Enforcement
- Misdemeanor, Sec. 10-9.501
- Adopted
- Ord. 1352, eff. August 24, 2006
Summary
Yolo County Code Sec. 10-9.303(a) requires anyone doing construction work under a building permit to implement Best Management Practices that prevent pollutants like soil, construction waste, and debris from reaching the County storm drain system or natural surface waters, to the maximum extent practicable.
(a) Any person performing construction activities for which a building permit has been issued shall implement appropriate Best Management Practices (BMPs) to prevent the discharge of pollutants, to the maximum extent practicable, from the site into the County storm drain system or natural surface waters. These pollutants may include, but are not limited to, soils, construction wastes or debris, contaminants from construction materials, tools, and equipment.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-21: Supplement 2026 S-21 includes: Local legislation current through Ord. 1584, effective June 25, 2026).
Full Breakdown
303 sits in Article 3 of the County's Stormwater Ordinance, Title 10, Chapter 9, adopted by Ord. 1352 in 2006. Beyond the general construction BMP duty in subsection (a), subsection (b) requires new development and redevelopment projects to carry post-construction BMPs controlling the volume, rate, and pollutant load of runoff, backed by a maintenance agreement with the County. Separately, Sec. 208 requires anyone covered by an industrial or construction activity NPDES stormwater discharge permit to comply with every provision of that state permit, and lets the Public Works Director demand proof of compliance before issuing a subdivision map, site plan, building permit, or improvement plan, during inspections, or during enforcement.
Under Sec. 301(c), any BMPs installed must be inspected and maintained on a written schedule for both wet and dry seasons, with inspection dates, maintenance descriptions, and the inspector's name kept on record and made available to the Administrator on request. Larger sites face additional state-driven paperwork found elsewhere in the code: surface disturbance over one acre requires a Storm Water Pollution Prevention Plan by a Qualified SWPPP Developer and a Notice of Intent under the State's Construction General Permit, while disturbance of one acre or less can instead proceed with a site-specific Erosion and Sediment Control Plan identifying the Best Management Practices to be used, consistent with California Stormwater Quality Association criteria.
Violations & Fines
Violating any Chapter 9 requirement, including the Sec. 10-9.303 BMP duty, is a misdemeanor under Sec. 10-9.501, punishable as set out in Title 1, Chapter 2 of the County Code (up to a $500 fine, up to six months in county jail, or both, with each day a separate offense). Sec. 10-9.502 additionally declares any violating condition a public nuisance, letting the County summarily abate it at the violator's expense or pursue a civil action to enjoin the conduct.
Frequently Asked Questions
Do I need an erosion control plan for a small home construction project?
Who enforces stormwater and erosion rules in unincorporated Yolo County?
What triggers the state Construction General Permit requirement?
Sources & Official References
Other rules in Yolo County
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