California Stormwater Intelligence
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Waterbody profile

Official Water Board record · 2026 cycle

Santa Margarita River (Lower)

Waterbody ID (WBID)
CAR9021100019980911161346
County / counties
San Diego
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 (6)

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
Benthic Community EffectsOther Cause148281Do Not Delist from 303(d) list (TMDL required list)Revised5A — TMDL still required—Low
ChlorpyrifosPesticides148263Do Not Delist from 303(d) list (TMDL required list)Revised5A — TMDL still required—Low
Indicator BacteriaPathogens128036Do Not Delist from 303(d) list (TMDL required list)Revised5A — TMDL still required—Low
NitrogenNutrients165387Do Not Delist from 303(d) list (TMDL required list)Revised5A — TMDL still required—Low
PhosphorusNutrients165388Do Not Delist from 303(d) list (TMDL required list)Revised5A — TMDL still required—Low
ToxicityTotal Toxics148278Do Not Delist from 303(d) list (TMDL required list)Revised5A — 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
CAR9021100019980911161346
CALWNUM
4902.110000, 4902.120000, 4902.130000, 4902.210000
WBD code
180703020504
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
9.85 Miles

Derived facility associations

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

Derived
CubeSmart 493

Fallbrook · Notice of Non-Applicability

derived_watershed_association

Derived by California Stormwater Intelligence

Defense Logistics Agency Disposition Services Pendleton DLA DSP

Camp Pendleton · Notice of Intent · 0.70 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Fallbrook Refuse Service

Fallbrook · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Fallbrook Water Reclamation Plant

Fallbrook · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Main Recycling Center

Camp Pendleton · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Rock Solid Stone

Fallbrook · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Rosemarys Mountain Quarry

Fallbrook · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

South Region Tertiary Treatment Plant SRTTP

Camp Pendleton · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Southland Fabrication

Fallbrook · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Southwest Regional Fleet Transportation SWRFT

Camp Pendleton · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Standish Precision Products

Fallbrook · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

US Marine Corps Air Station MCAS

Camp Pendleton · Notice of Intent · 0.61 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.