Environmental Rules in Orange County, CA (2026)

6 county-level rules, plus city-specific rules for 10 cities in Orange County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Orange County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Stormwater Management

Orange County's Water Quality Ordinance bars anyone in the unincorporated area from creating an illicit connection to the stormwater drainage system or causing a prohibited discharge into it, including excess irrigation runoff that carries pollutants. Section 4-13-40 applies regardless of intent, and OC Public Works can order cleanup, seek a nuisance abatement, or refer the case for criminal prosecution.

Orange County Bans Illicit Stormwater Discharges

Heavy Restrictions

Orange County Codified Ordinances § 4-13-40

(a)No person shall:(1)Construct, maintain, operate and/or utilize any illicit connection.(2)Cause, allow or facilitate any prohibited discharge.(3)Act, cause, permit or suffer any agent, employee, or independent contractor, to construct, maintain, operate or utilize any illicit connection, or cause, allow or facilitate any prohibited discharge.(4)Irrigate their property in a manner that causes ...

Full ordinance details →Official source ↗

Erosion Control

Any grading, clearing, brushing, or grubbing preparatory to grading in unincorporated Orange County requires a permit from the Building Official before work starts, with narrow exemptions for small fills, footings, and cemetery graves.

Orange County Grading Permit Required

Some Restrictions

Orange County Codified Ordinances § 7-1-805

No person shall conduct any grading, clearing, brushing, or grubbing on natural or existing grade that is preparatory to grading, without first having obtained a grading permit from the Building Official.

Full ordinance details →Official source ↗

Coastal Development

Development within the coastal zone of unincorporated Orange County requires a Coastal Development Permit (CDP) under OCCO §7-9-127 and the California Coastal Act. The County has certified Local Coastal Programs for the Newport Coast, Emerald Bay, and Aliso Viejo segments, with the California Coastal Commission retaining jurisdiction over uncertified segments.

Orange County Unincorporated Coastal Development Permits

Some Restrictions

California Coastal Commission — Coastal Zone Boundary

Coastal Zone Boundary Del Norte Humboldt Mendocino Sonoma Marin San Francisco San Mateo Santa Cruz Monterey San Luis Obispo Santa Barbara Ventura Los Angeles O...

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Flood Zones

Unincorporated Orange County requires a permit for any construction in a mapped Special Flood Hazard Area, and new buildings must have their lowest floor at least one foot above the base flood elevation.

Orange County Floodplain Development Rules

Some Restrictions

Orange County Codified Ordinances § 7-9-42.6

For buildings including manufactured homes, the elevation of the lowest floor, including the basement or cellar, shall be at least one (1) foot above the base flood elevation. ... Permits shall be required for all proposed construction and other development within Special Flood Hazard Areas (SFHA) on the Flood Insurance Rate Map (FIRM).

Full ordinance details →Official source ↗

Boat Dock Permits

A written County permit is required to build, extend, or alter any pier, dock, piling, bulkhead, or seawall in a County harbor, issued by the Harbors, Beaches and Parks Director.

Orange County Harbor Dock Permits

Some Restrictions

Orange County Codified Ordinances § 2-2-148

No person or agency shall build, maintain, extend or make structural alterations on any pier, dock, piling, bulkhead or seawall, or do any filling, excavating or dredging in a harbor, without first obtaining a written permit to do so from the Director. ... Within incorporated areas, however, the only signs, buildings, piers or other structures for which permits shall be required and which shall...

Full ordinance details →Official source ↗

Flood Elevation Requirements

In unincorporated Orange County's FP Floodplain Overlay District, new construction and substantial improvements must set the lowest floor, including basements, at least one foot above the base flood elevation, certified on a County Elevation Certificate before permit issuance.

Orange County 1-Foot Flood Elevation Freeboard

Some Restrictions

Orange County Codified Ordinances § 7-9-42.9(c)

The applications shall include a County of Orange "Elevation Certificate" identifying the base flood elevation and certifying that the planned elevation of the lowest floor, including basements, is at least one (1) foot above the base flood elevation.

Full ordinance details →Official source ↗