← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Waterbody ID (WBID)
CAR1059101019990217163525
County / counties
Modoc, Siskiyou
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 (9)

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
ArsenicMetals168712Do Not Delist from 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
Chlorophyll-aNutrients158412List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
MercuryMetals168714Do Not Delist from 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
NutrientsNutrients168715Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B Addressed by USEPA-approved TMDLLower Lost River
Oxygen, DissolvedNutrients158414Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLLower Lost River
pHOther Cause168716List on 303(d) list (being addressed by USEPA approved TMDL)Original5B Addressed by USEPA-approved TMDLLower Lost River
pH (high)Other Cause79038Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)Revised5B Addressed by USEPA-approved TMDLLower Lost River
Temperature, waterOther Cause158415List on 303(d) list (TMDL required list)Revised5A TMDL still requiredLow
TurbiditySediment158416List 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
Sep 16, 2026, 10:56 PM UTC
Waterbody ID
CAR1059101019990217163525
CALWNUM
10590000
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
772.56 Miles

Derived facility associations

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

Derived

No industrial stormwater facility is geographically associated with this waterbody.

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.