Draft California 2026 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Oak Creek Side Channel (Inyo County)
Water Body ID:	CAR6033012020230612043795
Water Body Type:	River & Stream


DECISION ID	163849	Region 6
Oak Creek Side Channel (Inyo County)

Pollutant:	Orthophosphate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 163849, Orthophosphate	Region 6
Oak Creek Side Channel (Inyo County)

LOE ID:

343657

Pollutant:

Orthophosphate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Fort Independence Indian Community of Paiute Indians of the Fort Independence Reservation, California data to determine beneficial use support and results are as follows:
1 of 1 samples exceeded the water quality threshold for OrthoPhosphate as P

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for OrthoPhosphate as P in this water body is 0.08 (mg/L), (as a Mean).

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: OC 5 (FIIR-Site 5)

Temporal Representation:

The samples were collected between the dates of 2019-07-16 and 2019-07-16

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference


DECISION ID	163848	Region 6
Oak Creek Side Channel (Inyo County)

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 163848, Total Dissolved Solids	Region 6
Oak Creek Side Channel (Inyo County)

LOE ID:

343700

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Fort Independence Indian Community of Paiute Indians of the Fort Independence Reservation, California data to determine beneficial use support and results are as follows:
0 of 1 samples exceeded the water quality threshold for Total Dissolved Solids

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Total Dissolved Solids in this water body is 72 (mg/L), (as a Mean).

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: OC 5 (FIIR-Site 5)

Temporal Representation:

The samples were collected between the dates of 2019-07-16 and 2019-07-16

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference

Line of Evidence (LOE) for Decision ID 163848, Total Dissolved Solids	Region 6
Oak Creek Side Channel (Inyo County)

LOE ID:

343695

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Fort Independence Indian Community of Paiute Indians of the Fort Independence Reservation, California data to determine beneficial use support and results are as follows:
0 of 1 samples exceeded the water quality threshold for Total Dissolved Solids

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Total Dissolved Solids in this water body is 72 (mg/L), (as a Mean).

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: OC 3 (FIIR-Site 3)

Temporal Representation:

The samples were collected between the dates of 2019-07-01 and 2019-07-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference