Environmental Rules in Yolo County, CA (2026)
6 county-level rules, plus city-specific rules for 1 city in Yolo County, California.
Verified from official government sources
Stormwater Management
Yolo County's Stormwater Ordinance, Sec. 10-9.201, bans any illicit discharge, anything but stormwater, into the County storm drain system, natural surface waters, or watercourses. The rule implements the county's Small MS4 General Permit under the federal Clean Water Act and applies to the unincorporated area.
Yolo County Stormwater Discharge Ordinance
Some RestrictionsYolo County Code of Ordinances § 10-9.201
Except as provided in Section 10-9.202, it shall be unlawful for any person to make or cause to be made an illicit discharge of any materials, including but not limited to pollutants or waters containing any pollutants that cause or contribute to a violation of applicable water quality standards, other than stormwater into the County storm drain system, natural surface waters, or watercourses.
Erosion Control
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.
Construction Site Erosion Control in Yolo County
Some RestrictionsYolo County Code of Ordinances § 10-9.303(a)
(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 debri...
Flood Zones
Any construction or development inside a Yolo County special flood hazard area needs a Development Permit before work begins, under Sec. 8-4.403. New and substantially improved homes must have their lowest floor elevated at least 1 foot above the base flood elevation, and the county's Floodplain Administrator reviews plans, grading, and utility locations.
Yolo County Flood Zone Development Permit Rules
Some RestrictionsYolo County Code of Ordinances § 8-4.403
A Development Permit shall be obtained before any construction or other development begins within any area of special flood hazards established in Section 8-4.302. Application for a Development Permit shall be made on forms furnished by Yolo County.
Boat Dock Permits
A dock in Yolo County only counts as a 'Permitted Dock' under Sec. 9-6.02(F) if it has received a County Use Permit or similar entitlement for mooring vessels. Sec. 9-6.11(B) then limits mooring at that dock to vessels that meet seaworthiness, inspection, and navigation requirements.
Boat Dock and Mooring Permits in Yolo County
Some RestrictionsYolo County Code of Ordinances § 9-6.02(F); § 9-6.11(B)
"Permitted Dock" or "Permitted Marina" is any structure, floating platform or building, attached to land or floating on piles driven into the bottom of the waterway, designed for and used as a place to moor a vessel, and has received a County Use Permit or similar entitlement for that use. ... A vessel may be moored at a permitted dock to the extent permitted by law if all of the following requ...
Vehicle Idling Restrictions
Yolo County caps engine idling at ten minutes for vehicles and equipment working in-channel under the Cache Creek Area Plan In-Channel Ordinance. The limit targets sand and gravel mining crews operating in the Cache Creek streambed, not general traffic countywide.
10-Minute Idling Cap for Cache Creek Mining
Light RestrictionsYolo County Code of Ordinances § 10-3.407(f)
All internal combustion engine driven equipment and vehicles shall be kept tuned according to the manufacturer’s specifications and properly maintained to minimize the leakage of oils and fuels. No vehicles or equipment shall be left idling for a period of longer than ten (10) minutes.
Flood Elevation Requirements
In special flood hazard areas, Yolo County's flood damage prevention ordinance requires new and substantially improved residential structures in AE, AH, and A1-30 zones to elevate the lowest floor at least one foot above the base flood elevation, with a Development Permit required first.
Yolo County Requires 1-Foot Freeboard Above Base Flood
Significant RestrictionsYolo County Code of Ordinances § 8-4.501(c)(1)
(c) Elevation and floodproofing. (1) Residential construction, new or substantial improvement, shall have the lowest floor, including basement: (i) In AE, AH, A1-30 Zones, elevated at least one (1) foot above the base flood elevation. (ii) In an AO zone, elevated above the highest adjacent grade to a height exceeding the depth number specified in feet on the FIRM...
Environmental Rules by City in Yolo County
1 cities in Yolo County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.
All Yolo County ordinances
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