California Stormwater Intelligence

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Waterbody profile

Official Water Board record · 2026 cycle

Arroyo Trabuco Creek, Upper

Waterbody ID (WBID): CAR9012200020200716063560
County / counties: Orange
Regional Water Board: Regional Board 9 - San Diego Region
Waterbody type: River & Stream
Condition category: Category 5 — 303(d) listed, TMDL required
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 / stressor	Decision ID	Final listing decision	Decision status	TMDL requirement status	TMDL project	TMDL priority
ToxicityTotal Toxics	105539	Do Not Delist from 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low

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: CAR9012200020200716063560
CALWNUM: 4901.22
WBD code: 180703010103
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: 6.88 Miles

Derived facility associations

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

Derived

3A Treatment Plant

Laguna Niguel · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Applied Medical Resources

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Applied Medical Resources

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Applied Medical Resources

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Applied Medical Resources

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Applied Medical Resources

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Forespar Products Corp

Rancho Santa Margarita · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

IMI Critical Engineering

Rancho Santa Margarita · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Laguna Hills · Notice of Non-Applicability

derived_watershed_association

Derived by California Stormwater Intelligence

Oso Parkway Crushing Facility and Batch Plant

Mission Viejo · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Rancho Sierra Vista Equestrian Center

San Juan Capistrano · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

San Juan Capistrano Equestrian Center

San Juan Capistrano · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

USPS Mission Viejo VMF

Mission Viejo · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Rancho Santa Margarita · No Exposure Certification

derived_watershed_association

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.