← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Mendocino Coast HU, Gualala River HA, Gualala River

Waterbody ID (WBID)
CAR1138502119980709123111
County / counties
Mendocino, Sonoma
Regional Water Board
Regional Board 1 - North Coast Region
Waterbody type
River & Stream
Condition category
Category 5 — 303(d) listed, TMDL required
Integrated Report cycle
2026

303(d) listings (5)

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
AluminumMetals168900Do Not Delist from 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
Benthic Community EffectsOther Cause169311List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
SedimentSediment168901List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLGualala River Sediment
Sedimentation/SiltationSediment69315List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLGualala River Sediment
Temperature, waterOther Cause155314Do Not Delist from 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
Sep 16, 2026, 10:56 PM UTC
Waterbody ID
CAR1138502119980709123111
CALWNUM
1113.810002, 1113.810003, 1113.820001, 1113.820003, 1113.820004, 1113.830002, 1113.830003, 1113.840302, 1113.840304, 1113.850101
WBD code
180101080906, 180101090101, 180101090102, 180101090103, 180101090104, 180101090105, 180101090106, 180101090107, 180101090108
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
685.36 Miles

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

Annapolis Transfer Station1 49I025382

Aluminum · most recent exceedance RY 2025 · association: derived nearby in watershed

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
Annapolis Transfer Station

Annapolis · Notice of Intent · 0.06 km away

derived_nearby_in_watershed

Derived by California Stormwater Intelligence

South Coast Transfer Station

Gualala · Notice of Intent · 0.64 km away

derived_receiving_water

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.