Skip to main content
CityRuleLookup

Antioch, CA Environmental Rules: Stormwater Management (2026)

Significant Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Governing sections
AMC §§ 6-9.06, 6-9.08, 6-9.05
NPDES permit
City of Antioch Permit No. CA0083313
Plan trigger
10,000+ sq ft new/replaced impervious surface
Administering official
City Engineer (Director)
Penalty class
Misdemeanor, chargeable as infraction

Summary

Antioch Municipal Code Chapter 9 bans any non-stormwater discharge into the city's storm drain system and requires an approved stormwater control plan for larger development projects under the city's NPDES permit. Violations are misdemeanors that can be charged as infractions at the officer's discretion.

(A) The release of non-stormwater discharges to the city's stormwater system is prohibited. (B) The discharge of stormwater from premises or an activity that causes or contributes to a violation of receiving water limitations in the city's NPDES permit is prohibited.

Full Breakdown

06(A) prohibits the release of any non-stormwater discharge into the city's stormwater system, with narrow exemptions in (C) and (D) for permitted NPDES discharges, natural groundwater flows, and specific approved categories like landscape irrigation runoff and dechlorinated pool water. 08 separately bans unauthorized drainage connections to the storm system and any discharge that creates floating or deposited matter, altered temperature or oxygen levels, visible oil sheen, or conditions harmful to aquatic life or human consumption. 3. 03. The chapter implements the city's own NPDES Permit No.

CA0083313 issued under the state Porter-Cologne Water Quality Control Act and the federal Clean Water Act. 09 layers on ongoing housekeeping duties: property owners must keep sidewalks free of dirt and litter, sweep sidewalk debris into disposal receptacles rather than the gutter, and keep parking lots and paved areas clean enough to avoid discharging pollutants. 15.

Violations & Fines

Violating any provision of Chapter 9 is a misdemeanor under § 6-9.12, though the enforcement officer or City Attorney may instead charge it as an infraction. A misdemeanor conviction carries a fine or imprisonment up to the limits in Cal. Gov't Code § 36901; an infraction conviction carries a fine up to the limit in Cal. Gov't Code § 36900. Each day a violation continues is a separate offense under § 6-9.14, and the city can also pursue civil actions and cost recovery under §§ 6-9.17 and 6-9.18.

Frequently Asked Questions

Can I hose pollutants into an Antioch storm drain?
No. AMC § 6-9.06(A) prohibits any non-stormwater discharge into the city's stormwater system, with only narrow exemptions such as NPDES-permitted discharges, natural groundwater flows, and a short list of Regional Water Quality Control Board-approved categories like landscape irrigation.
When does a project need a stormwater control plan in Antioch?
Section 6-9.05 requires a stormwater control plan meeting the Contra Costa Clean Water Program's C.3. Guidebook for any development creating or replacing 10,000 square feet or more of impervious surface, a threshold effective since August 15, 2006, down from the original one-acre trigger.
What is the penalty for a stormwater violation in Antioch?
Section 6-9.12 makes any Chapter 9 violation a misdemeanor, punishable under § 6-9.13 by a fine or imprisonment up to the Cal. Gov't Code § 36901 limits, though the officer or City Attorney can instead charge it as an infraction under the § 36900 limits.

Sources & Official References

Other rules in Antioch

All Antioch rules

California rules heatmap·Compare Antioch to another location·View the California environmental rules overview

Get notified when Stormwater Management in Antioch, CA changes

We'll email you the moment we detect a change in the code. No spam, unsubscribe anytime.

We'll never sell or share your email. One-click unsubscribe in every email.

See something wrong?

Help us keep this page accurate. If you notice an error or outdated information, let us know.

Stormwater Management in Nearby Cities

How other cities in Contra Costa County handle stormwater management.

Brentwood, CA
Some Restrictions
San Ramon, CA
Significant Restrictions