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Waterbody profile

Official Water Board record · 2026 cycle

Arrowhead, Lake

Waterbody ID (WBID)
CAL6282000020000215164600
County / counties
San Bernardino
Regional Water Board
Regional Board 6 - Lahontan Region
Waterbody type
Lake & Reservoir
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 / stressorDecision IDFinal listing decisionDecision statusTMDL requirement statusTMDL projectTMDL priority
MercuryMetals170119Do Not Delist from 303(d) list (TMDL required list)Revised5A TMDL still requiredMedium

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
CAL6282000020000215164600
CALWNUM
9628.2
WBD code
180902080103
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
736.2 Acres

Derived facility associations

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

Derived
Maintenance Operations Transpo

Lake Arrowhead · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Willow Creek Waste Water Treatment Plant

Lake Arrowhead · 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.