← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Oxford Retention Basin (Los Angeles County)

Waterbody ID (WBID)
CAL4046100020210322040715
County / counties
Los Angeles
Regional Water Board
Regional Board 4 - Los Angeles Region
Waterbody type
Lake & Reservoir
Condition category
Category 5 — 303(d) listed, TMDL required
Integrated Report cycle
2026

303(d) listings (3)

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
CopperMetals140609List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
Indicator BacteriaPathogens150316List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
ZincMetals140611List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow

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
CAL4046100020210322040715
CALWNUM
4404.61
WBD code
180701040403
Geometry
Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)

Location

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

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Watershed
Assessed size
3.14 Acres

Facilities with an NAL exceedance for a listed pollutant (1)

Geographically associated industrial stormwater facilities whose reported results exceeded an Industrial General Permit Numeric Action Level for a pollutant this waterbody is listed for.

Derived

Boatyard4 19I020189

Zinc · most recent exceedance RY 2015 · association: derived watershed association

This is derived co-occurrence between a calculated NAL comparison and the official 303(d) listing for this waterbody. An NAL exceedance triggers Exceedance Response Actions under the permit; it is not a violation and does not establish that any facility caused or contributed to this impairment.

Derived facility associations

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

Derived
Boatyard

Marina Del Rey · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Fedex SMOA

Marina Del Rey · Notice of Intent · 0.90 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

Windward Yacht Repair Inc

Marina Del Rey · Notice of Intent

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.