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Stanislaus County, CA Environmental Rules: Stormwater Management (2026)

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

Key Facts

Governing section
§ 14.14.050
Enforcing agency
Department of Public Works
Spill notification window
24 hours (§ 14.14.130)
Abatement plan deadline
30 days after notice
Base penalty class
Misdemeanor or infraction

Summary

Stanislaus County bans any nonstormwater discharge into the county's stormwater conveyance system outside a short exemption list. Even an exempt discharge loses its exemption the moment the Regional Water Quality Control Board or the county's enforcement official finds it violates a stormwater permit or threatens public health.

City-specific rules exist: Modesto has its own stormwater management rules that differ from Stanislaus County's county-level regulations. If you live in Modesto, check the city-specific page instead.

A. Except as provided in Section 14.14.060, it is unlawful for any person to make or cause to be made any nonstormwater discharge. B. Notwithstanding the exemptions provided by Section 14.14.060, if the Regional Water Quality Control Board or the enforcement official determines that any otherwise exempt discharge causes or significantly contributes to violations of any stormwater permit, or conveys significant quantities of pollutants to a surface water or stormwater conveyance, or is a danger to public health or safety, such discharge shall be prohibited from entering the stormwater conveyance system.

Full Breakdown

060: things like water-line flushing, air-conditioning condensate, individual residential car washing, and firefighting flows. 050(B) strips that protection back: if the Regional Water Quality Control Board or the county's enforcement official determines an otherwise-exempt discharge causes or significantly contributes to a stormwater permit violation, conveys significant pollutants to surface water, or endangers public health or safety, the discharge must stop from entering the system regardless of its listed exemption. 150, and can issue a written notice and order to abate by personal service or certified mail; the recipient then has thirty days (or a shorter period stated in the notice) to submit an explanation and a correction plan. Failure to comply lets the director perform the abatement work and bill the property owner. 130.

Violations & Fines

Violating any provision of Chapter 14.14 is a misdemeanor under Section 14.14.180, unless the director of public works or the district attorney elects to charge it as an infraction instead. Each day a violation continues counts as a separate offense. A violation is also declared a public nuisance under Section 14.14.150(B), letting the county abate it directly and recover its costs from the property owner, in addition to any Clean Water Act or Porter-Cologne Act sanctions the discharge may separately trigger.

Frequently Asked Questions

Can I wash my car in my Stanislaus County driveway?
Yes. Individual residential car washing on private property is specifically exempted under Section 14.14.060(B)(14), as long as no commercial enterprise or nonprofit fundraiser is running the wash. Runoff from a commercial car wash operation is not covered by this exemption.
What happens if my exempt discharge is polluting a creek?
The exemption disappears. Section 14.14.050(B) lets the Regional Water Quality Control Board or the county's enforcement official revoke the protection for any listed exempt discharge that is found to significantly contribute to a permit violation or endanger public health, forcing it to stop entering the conveyance system.
Who do I call if I see an illegal discharge into a storm drain?
Report it to the Stanislaus County Department of Public Works, which administers Chapter 14.14 under Section 14.14.150. Property owners who discover a pollutant release on their own land must also notify the enforcement official within 24 hours per Section 14.14.130.

Sources & Official References

Other rules in Stanislaus County

All Stanislaus County rules

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