Stormwater Management: Petaluma vs Sonoma
How do stormwater management rules compare between Petaluma, CA and Sonoma, CA?
Petaluma has fewer restrictions than Sonoma.
Petaluma, CA
Sonoma County
Petaluma Code Ch. 15.80 prohibits discharge of pollutants to the City's MS4 storm drain system. Illicit connections and prohibited discharges are violations subject to administrative and civil penalties.
View full Petaluma rules →Sonoma, CA
Sonoma County
Sonoma operates under a State NPDES Phase II MS4 permit and bans non-stormwater discharges into the city's storm drains, which flow untreated to Nathanson, Sonoma, and Fryer Creeks.
View full Sonoma rules →Key Facts Comparison
| Fact | Petaluma | Sonoma |
|---|---|---|
| Code | Petaluma Code Ch. 15.80 | - |
| Spill Reporting | Required (§15.80.190) | - |
| BMPs | Required during construction | - |
| Code section | - | SMC Ch. 13.32 |
| Permit | - | State NPDES Phase II Small MS4 |
| SWCP threshold | - | 5,000 sq ft impervious |
| Mitigation threshold | - | 2,500 sq ft impervious |
| Receiving waters | - | Nathanson, Sonoma, Fryer Creeks |
Highlighted rows indicate differences between cities.
Petaluma FAQ
What if I spill paint?
Contain immediately, do not wash to storm drain, and report to the City.
Sonoma FAQ
Can I wash my car in the driveway?
Residential car washing is generally allowed, but soapy water flowing into the gutter is an illicit discharge under SMC 13.32. The city recommends washing on grass or at a commercial car wash that routes wash water to the sanitary sewer.
Do I need a Stormwater Control Plan for a small remodel?
Only if the project creates or replaces 5,000 sq ft or more of impervious surface. Smaller projects creating 2,500+ sq ft must still mitigate downstream impacts per the NPDES permit.
Compare other topics
See how Petaluma and Sonoma compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool