← Impaired waters

Waterbody profile

Official Water Board record · 2026 cycle

Hopper Creek

Waterbody ID (WBID)
CAR4034100020020131112807
County / counties
Ventura
Regional Water Board
Regional Board 4 - Los Angeles 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 / stressorDecision IDFinal listing decisionDecision statusTMDL requirement statusTMDL projectTMDL priority
SulfatesToxic Inorganics69376Do Not Delist from 303(d) list (TMDL required list)Original5A TMDL still requiredLow
Total Dissolved SolidsSALINITY/TOTAL DISSOLVED SOLIDS/CHLORIDES/SULFATES69521Do Not Delist from 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, 10:56 PM UTC
Waterbody ID
CAR4034100020020131112807
CALWNUM
4403.41
WBD code
180701020801, 180701020802
Geometry
Official Water Board GIS (CA_WATERBOARDS_GIS_FINAL_2026)

Location

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

Loading map…
Watershed
Assessed size
13.6 Miles

Derived facility associations

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

Derived
Ameron Pole Prod

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Bus Garage

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Fillmore Auto Dismantling

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Fillmore Piru Citrus Assoc

Piru · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Grimes Rock Inc

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

MRC Rock and Sand

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Rancho San Cristobal Clay Mine

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Rehart

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Sespe 14 Tank Battery

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Sespe Oilfield

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

Shiells Canyon Field

Fillmore · Notice of Intent

derived_watershed_association

Derived by California Stormwater Intelligence

United Chemical

Piru · No Exposure Certification

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.