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Waterbody profile

Official Water Board record · 2026 cycle

Malibu Lagoon

Waterbody ID (WBID)
CAE4042100019990201160355
County / counties
Los Angeles
Regional Water Board
Regional Board 4 - Los Angeles Region
Waterbody type
Estuary
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 Cause99794Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLMalibu Lagoon Benthic Comm. Effects (71)
EutrophicNutrients69987List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLMalibu Creek Nutrients (50)
Indicator BacteriaPathogens69576List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLMalibu Pathogens (47 in part)
pHOther Cause68414Do Not Delist from 303(d) list (TMDL required list)Original5A TMDL still requiredLow
Swimming RestrictionsPathogens76137List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLMalibu Pathogens (47 in part)
Viruses (enteric)Pathogens76135List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLMalibu Pathogens (47 in part)

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
CAE4042100019990201160355
CALWNUM
4404.160000, 4404.210000, 4404.310000
WBD code
180701040104, 180701040204, 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
24.97 Acres

Facilities with an NAL exceedance for a listed pollutant (2)

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

Santa Monica Malibu Usd4 19I004720

pH · most recent exceedance RY 2018 · association: derived watershed association

Tapia WRF4 19I005211

pH · 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
Santa Monica Malibu Usd

Santa Monica · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Tapia WRF

Calabasas · 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.