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Sonoma, CA Environmental Rules: Stormwater Management (2026)

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

Key Facts

Governing chapter
SMC Ch. 13.32, Stormwater Management and Discharge Control
Enforcement official
City public works director or designee
Spill notification window
24 hours to notify enforcement agency
Correction window
72 hrs (point source) / 30 days (nonpoint)
Civil penalty
Up to $1,000 per day of violation

Summary

The City of Sonoma bans illicit discharges and connections into its stormwater conveyance system under SMC 13.32.050, requires businesses and construction sites to use best management practices, and treats violations as a public nuisance enforceable by the public works director as enforcement official.

13.32.050 Discharge prohibitions. ... A. Illicit Discharges. ... Except as provided in SMC 13.32.060, it is unlawful and a public nuisance for any person to make or cause to be made any illicit discharge into the stormwater conveyance system in excess of incidental runoff. ... ... B. Illicit Connection. The construction, use, maintenance or continued existence of illicit connections is prohibited. This prohibition includes illicit connections made in the past, regardless of whether the connection was permissible under law or practices applicable or prevailing at the time of the connection. C. Litter, Dumps, and Stockpiles. Throwing, depositing, leaving, abandoning, maintaining or keeping materials or wastes on public or private lands in a manner and place where they may result in an illicit discharge is prohibited.

View official code

Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 13-2025, passed December 3, 2025).

Full Breakdown

050: making any illicit discharge (any discharge that is not entirely stormwater) into the city's stormwater conveyance system beyond incidental runoff; constructing, using, or maintaining any illicit connection to that system, even one built before the ordinance existed; and throwing, depositing, or leaving litter, dumped materials, or stockpiles anywhere they may cause an illicit discharge. 060, becomes unlawful again if the Regional Water Quality Control Board or the city's enforcement official determines it significantly contributes to violations of the applicable water quality plan standard. 205. 110. 120, with costs borne by the property owner.

Violations & Fines

A violation is enforced first through SMC 13.32.130's escalation procedure: an initial site visit and verbal warning giving the responsible party up to 72 hours to correct a point-source discharge, or 30 days for a nonpoint-source discharge posing an environmental threat, followed by a written notice of violation if uncorrected. Every violation is also declared a public nuisance and is punishable under the general penalty in Chapter 1.12 SMC. The city may instead pursue a civil action, and anyone who willfully violates the chapter or a permit issued under it faces a civil penalty of up to $1,000 per day the violation continues, with each day treated as a separate offense; a court weighs harm caused, duration, the violator's finances, and any corrective action taken in setting the amount. The city can also recover cleanup costs from the property owner or the person who caused the violation.

Frequently Asked Questions

What counts as an illegal discharge into Sonoma's storm drains?
SMC 13.32.050 bans any illicit discharge, meaning anything entering the stormwater conveyance system that is not entirely stormwater, beyond trivial incidental runoff. It also bans illicit connections to the system and dumping litter or materials where they could wash into it. Certain listed discharges like foundation drain water or dechlorinated pool water are exempt unless they contribute to a water quality violation.
What do I have to do if I discover a pollutant spill in the City of Sonoma?
SMC 13.32.110 requires anyone who learns of a pollutant release or illicit discharge on their property that could reach the stormwater system to immediately contain and clean it up and notify the city's enforcement agency within 24 hours of discovering the release.
What are the penalties for a stormwater violation in Sonoma?
Beyond the general penalty in Chapter 1.12 SMC, SMC 13.32.130 lets the city pursue a civil action with a penalty of up to $1,000 per day the violation continues, with each day counted as a separate offense. The city can also recover the cost of cleaning up any affected public property from the responsible party.

Sources & Official References

Other rules in Sonoma

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Stormwater Management in Nearby Cities

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