← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Isabella Lake

Waterbody ID (WBID)
CAL5542101020020418145333
County / counties
Kern
Regional Water Board
Regional Board 5 - Central Valley 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
MercuryMetals131328Do Not Delist from 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
Oxygen, DissolvedNutrients75478Do Not Delist from 303(d) list (TMDL required list)Original5A TMDL still requiredLow
pHOther Cause75847List on 303(d) list (TMDL required list)Original5A 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, 10:57 PM UTC
Waterbody ID
CAL5542101020020418145333
CALWNUM
7554.100202, 7554.210000, 7554.220506, 7554.220707
WBD code
180300010606, 180300010607, 180300020702
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
11707.08 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

Kern Valley R and TS5F15I023359

pH · most recent exceedance RY 2018 · 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
Cranes Waste Oil Inc

Weldon · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Kern Valley R and TS

Kernville · 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.