California Stormwater Intelligence
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Waterbody profile

Official Water Board record · 2026 cycle

Arroyo Seco (Sonoma County)

Waterbody ID (WBID)
CAR2064002020210519034958
County / counties
Sonoma
Regional Water Board
Regional Board 2 - San Francisco Bay Region
Waterbody type
River & Stream
Condition category
Category 4a — TMDL completed
Integrated Report cycle
2026

303(d) listings (1)

Each row is one official listing decision from Appendix A of the Final 2026 California Integrated Report. Source terminology is preserved as published.

Pollutant / stressorDecision IDFinal listing decisionDecision statusTMDL requirement statusTMDL projectTMDL priority
Indicator BacteriaPathogens148538List on 303(d) list (being addressed by USEPA approved TMDL)Revised5B — Addressed by USEPA-approved TMDLSonoma Creek Pathogens—

Source & provenance

Agency
California State Water Resources Control Board
Report
Final 2026 California Integrated Report
Dataset
Appendix A — 2026 303(d) List of Impaired Waters
Imported
Aug 21, 2026, 12:44 AM UTC
Waterbody ID
CAR2064002020210519034958
CALWNUM
2206.400201, 2206.400202, 2206.400203
WBD code
180500020502
Geometry
Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)
View official Water Board fact sheet ↗Download Appendix A source file ↗

Location

Official 2026 Water Board geometry. Demonstration facility markers are shown for context only.

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Watershed
—
Assessed size
7.36 Miles

Derived facility associations

Industrial stormwater facilities geographically associated with this waterbody. These are derived spatial associations, not Water Board findings.

Derived
Carneros Hills Winery

Sonoma · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Marin Sun Farms Inc

Petaluma · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Patz & Hall Winery

Sonoma · No Exposure Certification · 0.56 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Sebastiani vineyards and Winery

Sonoma · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Sonoma Bottling Center

Sonoma · Notice of Intent · 0.57 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Vineburg Wine Co Inc

Sonoma · Notice of Intent · 0.27 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Facility records are official Industrial General Permit registrations, but the association between a facility and this waterbody is derived geographically (proximity or shared HUC12 subwatershed) and is not a Water Board receiving-water determination. Where a permit carries a Water Board-stated TMDL requirement naming this water, it is listed separately above.