Merced River, Upper

Waterbody ID (WBID): CAR5373006120020716114140
County / counties: Mariposa
Regional Water Board: Regional Board 5 - Central Valley Region
Waterbody type: River & Stream
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 / stressor	Decision ID	Final listing decision	Decision status	TMDL requirement status	TMDL project	TMDL priority
Alkalinity as CaCO3Other Cause	159027	Do Not Delist from 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low

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: CAR5373006120020716114140
CALWNUM: 6537.220000, 6537.300401, 6537.300403, 6537.300404, 6537.300501, 6537.300503, 6537.300601, 6537.500301, 6537.500304, 6537.500402, (Total Count: 11)
WBD code: 180400080305, 180400080306, 180400080307, 180400080501, 180400080503, 180400080603
Geometry: Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)

View official Water Board fact sheet ↗Download Appendix A source file ↗

Location

Official 2026 Water Board geometry. Demonstration facility markers are shown for context only.

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Watershed: —
Assessed size: 42.52 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.