California Stormwater Intelligence

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Waterbody profile

Official Water Board record · 2026 cycle

Powell Slough (Colusa County)

Waterbody ID (WBID): CAR5201000020190625028803
County / counties: Colusa
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 (2)

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
AluminumMetals	153951	List on 303(d) list (TMDL required list)	Revised	5A — TMDL still required	—	Low
Oxygen, DissolvedNutrients	124113	List on 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: Aug 21, 2026, 12:44 AM UTC
Waterbody ID: CAR5201000020190625028803
CALWNUM: 5520.100002, 5520.210000
WBD code: 180201040807
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: 4.45 Miles

Derived facility associations

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

Derived

ACC Williams Bio Energy Project

Williams · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Arbuckle · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

American Commodity Company

Williams · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

American Commodity Company BioEnergy Project

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Big M Automotive

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Coach Maintenance Co

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Colusa County Airport

Colusa · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Farmers Fresh Mushrooms California Inc

Colusa · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

julio brincats high tech towing dism 26630

Williams · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Morning Star co

Williams · Notice of Non-Applicability

derived_watershed_association

Derived by California Stormwater Intelligence

Morning Star co

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Ramos Oil Company Williams

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

REACH 080 Williams CA

Williams · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Simplot Grower Solutions Colusa

Colusa · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Tamaki Rice Corporation

Williams · No Exposure Certification

derived_watershed_association

Derived by California Stormwater Intelligence

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Wadham Energy Ltd Part

Williams · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Western Ready Mix Concrete Co Inc

Colusa · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Wilbur Ellis Company LLC Colusa

Colusa · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Williams Redi Mix dba Clearlake Lava Inc

Williams · 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.