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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Heavenly Valley Creek (USFS boundary to Trout Creek)
Water Body ID:	CAR6341003120021219154348
Water Body Type:	River & Stream


DECISION ID	162049	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Chloride
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Unknown Point Source
TMDL Name:	Heavenly Valley Creek (source to USFS boundary) Sediment
TMDL Project Code:	655
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Seven hundred and forty one of the 742 samples exceed the water quality objective, which is based on a site-specific objective of 0.15 mg/L for Trout Creek, which applies to Heavenly Valley Creek since it is tributary to Trout Creek. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seven hundred and forty one of the 742 samples exceed the water quality objective, and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 162049, Chloride	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

34056

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

733

Number of Exceedances:

732

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Seven-hundred and thirty-two of the 733 samples collected exceeded Trout Creek's site-specific objective.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Chapter 2 of the Lahontan Region's Basin Plan states Heavenly Valley Creek (USFS boundary to Trout Creek) as being tributary to Trout Creek and thus, the objective for Trout Creek applies to the Heavenly Valley Creek (USFS boundary to Trout Creek) water body. The site-specific objective for Chloride in Lahontan Basin Plan Table 3-14 for Trout Creek is 0.15 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from the HVC-1, HVC-2, and HVC-3 stations.

Temporal Representation:

Samples were collected approximately once a month from November 1983 to May 2010.

Environmental Conditions:

QAPP Information:

Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 162049, Chloride	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

4616

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 162049, Chloride	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338370

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan Objective that is incorporated by in the Water Quality Control Plan, Lahontan Region for chloride is an annual average of 0.15 mg/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2019-05-18 and 2020-05-30

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162049, Chloride	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338442

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan Objective that is incorporated by in the Water Quality Control Plan, Lahontan Region for chloride is an annual average of 0.15 mg/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2014-05-17 and 2019-05-18

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162049, Chloride	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338431

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan Objective that is incorporated by in the Water Quality Control Plan, Lahontan Region for chloride is an annual average of 0.15 mg/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2014-05-17 and 2014-05-17

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	169694	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One of the 401 samples exceed the water quality objective, which is a 4-day objective for unionized ammonia. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of 401 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169694, Ammonia	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338289

Pollutant:

Ammonia (Unionized)

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:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The un-ionized ammonia water quality objective to protect aquatic life in freshwater is temperature and pH dependent and is calculated according to the equation for the four-day criterion defined in Chapter 3 of The Water Quality Control Plan for the Lahontan Region.

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: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2008-05-10 and 2008-05-10

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169694, Ammonia	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

31723

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

400

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of the 400 samples exceeded the water quality objective for un-ionized ammonia. The single exceedance occurred in HVC-3 on 11/5/1994. Total ammonia nitrogen samples were converted to unionized ammonia using the Basin Plan formulas on p.3-3 and p.3-4.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan 4-day objective for unionized ammonia is a function of pH, temperature, and the presence of salmonids.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the following sites: HVC-1, HVC-2, and HVC-3.

Temporal Representation:

Samples were collected from 1993 to 2010.

Environmental Conditions:

QAPP Information:

Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.

QAPP Information Reference(s):


DECISION ID	169692	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. One of the 17 samples exceeds the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of 17 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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:

Line of Evidence (LOE) for Decision ID 169692, Indicator Bacteria	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

336780

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use in waters other than Lake Thaoe, where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the days of 2020-05-30 and 2020-05-30 .

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169692, Indicator Bacteria	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

336777

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the days of 2009-05-16 and 2021-05-15 .

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169692, Indicator Bacteria	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

336815

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the days of 2008-05-10 and 2014-05-17 .

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169692, Indicator Bacteria	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

336789

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and the results are as follows: 1 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the days of 2008-05-10 and 2013-05-11 .

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	169693	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Nitrogen, Nitrate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Zero of the 721 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 721 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169693, Nitrogen, Nitrate	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

31722

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

714

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 714 samples exceeded the water quality objective for Nitrate. The data was reported as Nitrate as N which was converted to Nitrate.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

he Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrate is 45 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the following sites: HVC-1, HVC-2, and HVC-3.

Temporal Representation:

Samples were collected from 11/14/1983 to 5/25/2010.

Environmental Conditions:

QAPP Information:

Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 169693, Nitrogen, Nitrate	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338845

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate (NO3 as N) incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2019-05-18 and 2019-05-18

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169693, Nitrogen, Nitrate	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338930

Pollutant:

Nitrate as Nitrate (NO3)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Nitrate incorporated by reference in the Water Quality Control Plan, Lahontan Region is 45000 ug/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2012-05-12 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169693, Nitrogen, Nitrate	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338917

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2016-05-14 and 2018-05-19

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169693, Nitrogen, Nitrate	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

338934

Pollutant:

Nitrate as Nitrate (NO3)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Nitrate incorporated by reference in the Water Quality Control Plan, Lahontan Region is 45000 ug/L (Water Quality Control Plan, Lahontan Region).

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2005-05-21 and 2011-05-14

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	79432	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Nitrogen, Nitrite
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the 477 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 477 samples exceeded the objective (MCL) and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 79432, Nitrogen, Nitrite	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

31674

Pollutant:

Nitrite as Nitrite NO2

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

477

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 477 samples exceeded the water quality objective for nitrite.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the following sites: HVC-1, HVC-2, and HVC-3.

Temporal Representation:

Samples were collected from 2/19/1993 to 5/25/2010.

Environmental Conditions:

QAPP Information:

Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.

QAPP Information Reference(s):


DECISION ID	162050	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the 28 samples are below the concentration objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 28 samples are below the concentration objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 162050, Oxygen, Dissolved	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339278

Pollutant:

Oxygen, Dissolved

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:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

For waters with the beneficial uses of COLD, COLD with SPWN, WARM, and WARM with SPWN, the minimum dissolved oxygen concentration shall not be less than that specified in Table 3-6. (Water Quality Control Plan, Lahontan Region)

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: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2005-05-21 and 2014-05-17

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162050, Oxygen, Dissolved	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339069

Pollutant:

Oxygen, Dissolved

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:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2003-05-10 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162050, Oxygen, Dissolved	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339294

Pollutant:

Oxygen, Dissolved

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:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2006-05-20 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162050, Oxygen, Dissolved	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339158

Pollutant:

Oxygen, Dissolved

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:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2009-05-16 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	169691	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the 31 samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 31 samples exceeded the objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169691, Specific Conductivity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340496

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's 'Chemical Constituents' objective. The California Secondary MCL for specific conductivity is 900 uS/cm.

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2005-05-21 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169691, Specific Conductivity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340379

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2002-05-04 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169691, Specific Conductivity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340520

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2003-05-10 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 169691, Specific Conductivity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340674

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2009-05-16 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	162051	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollution

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Nine lines of evidence is available in the administrative record to assess this pollutant. The Lahontan Basin Plan's narrative pH objective is an antidegradation-based objective that requires that there be no change greater than 0.5 pH units in waters designated for COLD and WARM beneficial uses. ( A pH range of 6.5 to 8.5 units applies to "all other waters.") Listing Policy section 3.10 contains directions for assessment based on trends in water quality. Though the LOE (34620) associated with this decision finds that 88 of the 733 samples exceed the water quality objective, this can not be determined with certainty because baseline conditions (normal ambient pH) has not been established for this waterbody. As such, it is more accurate to report the use rating for this decision as insufficient information instead of fully supporting. Staff recommend some trend analysis be completed on this data set before next listing cycle to determine the normal ambient pH for this waterbody. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. It is not possible to determine with certainty if 88 of the 733 samples exceeded the objective because the objective requires that a normal ambient pH for the waterbody be established to determine compliance. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339867

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan's regionwide objective for pH states: 'In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis.'

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: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2009-05-16 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340077

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2005-05-21 and 2014-05-17

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339980

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 14 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2003-05-10 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339614

Pollutant:

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 League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 14 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2003-05-10 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

339989

Pollutant:

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 League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2009-05-16 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340121

Pollutant:

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 League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2004-05-22 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340186

Pollutant:

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 League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2005-05-21 and 2014-05-17

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

34620

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

733

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 733 minimums and maximums of pH data had 88 exceedences.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the Region, the pH shall not be depressed below 6.5 nor raised above 8.5. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis. [There is no site specific objective for pH for this water body]

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the the HVC-1, HVC-2, and HVC-3 stations.

Temporal Representation:

Samples were collected approximately once a month from November 1983 to May 2010.

Environmental Conditions:

QAPP Information:

Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 162051, pH	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340004

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed League to Save Lake Tahoe Truckee Tahoe Snapshot D data for Heavenly Valley Creek (USFS boundary to Trout Creek) to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2004-05-22 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	78849	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. One of the 723 samples exceed the water quality objective. The samples were collected between 11/14/1983 and 5/25/2010 and this sampling frequency seems sufficient to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect trends in the temperature regime if such trends exist. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the 723 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 78849, Temperature, water	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

31703

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

723

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of the 723 samples exceeded the evaluation guideline for temperature in this water body.

Data Reference:

Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit above or below the natural temperature. For waters designated COLD, the temperature shall not be altered.

Objective/Criterion Reference:

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

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis

Spatial Representation:

Samples were collected in the following locations in this water body: Heavenly Valley Creek; Downstream of Pioneer Heavenly Valley Creek; 250' upstream of Pond #2 Heavenly Valley Creek; 25' downstream of Meadow Crest Dr.

Temporal Representation:

Samples collected between 11/14/1983 and 5/25/2010.

Environmental Conditions:

QAPP Information:

South Tahoe Public Utility District Laboratory Quality Assurance Program by Terry Powers, Laboratory Director (March 30, 2009)

QAPP Information Reference(s):


DECISION ID	162052	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Turbidity
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:	Pollution

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Two of the 26 samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of 26 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 162052, Turbidity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340965

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL) based upon drinking water standards specified in Title 22 of the California Code of Regulations. The Lahontan Basin Plan also has regionwide turbidity objective for other beneficial uses that states: Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10%.

Objective/Criterion Reference:

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

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Lahontan Basin Plan's 'Chemical Constituents' objective. The Secondary MCL for turbidity is 5 NTU. Calculation of a numeric objective for other beneficial uses requires comparison with upstream or other background data which may not be available as part of the data used for water quality assessment.

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV2-00 (Heavenly Valley Creek upstream of Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2002-05-04 and 2013-05-11

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162052, Turbidity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340817

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-00 (Heavenly Valley Creek at Trout Creek Confluence).

Temporal Representation:

The samples were collected between the dates of 2003-05-10 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162052, Turbidity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340830

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-01 (Heavenly Valley Creek above Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2009-05-16 and 2021-05-15

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634

Line of Evidence (LOE) for Decision ID 162052, Turbidity	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

340838

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Truckee Tahoe Snapshot Day for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: SLT-HEAV-02 (Heavenly Valley Creek upstream of Pioneer Trail).

Temporal Representation:

The samples were collected between the dates of 2007-05-12 and 2014-05-17

Environmental Conditions:

QAPP Information:

Tahoe Truckee Snapshot QAPP

QAPP Information Reference(s):

Lahontan Water Board - TahoeTruckeeSnapshotQAPP - League to Save Lake Tahoe Truckee Tahoe Snapshot D - 402634


DECISION ID	79971	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

Pollutant:	Sedimentation/Siltation
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	A Source Unknown
TMDL Name:	Lake Tahoe Nutrients/Sediment
TMDL Project Code:	198
Date TMDL Approved by USEPA:	08/16/2011
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. 303(d) listing decisions made prior to 2006 were not held in an assessment database. Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle, however; the previous conclusion has changed since the Lake Tahoe TMDL, which partly addresses the sediment impairment within this segment of Heavenly Creek, was adopted after the 2010 Integrated Report. Heavenly Valley Creek (from the USFS boundary to Trout Creek) is a tributary to Lake Tahoe. On the ground efforts required by the Lake Tahoe TMDL that focus on (1) stabilizing disturbed areas within the forested uplands and (2) managing and treating urban uplands (e.g. street sweeping, installing and maintaining infiltration and stormwater treatment facilities) will also achieve pollutant load reductions of sediment within this waterbody segment, which is tributary to Lake Tahoe. The largest source of sediment in this reach of Heavenly Valley Creek is urban storm water runoff and erosion of disturbed undeveloped areas. The Lake Tahoe TMDL identifies actions that resource management agencies, Lake Tahoe municipalities (El Dorado and Placer Counties, and the City of South Lake Tahoe) and California Department of Transportation must take to reduce fine sediment and nutrient loading to the Lake. Municipal Stormwater NPDES permits require the Lake Tahoe municipalities and CalTrans to develop and implement comprehensive pollutant load reduction programs (PLRPs) to meet specified pollutant load reduction requirements. Expected implementation measures include a variety of alternative treatment options, roadway operation practices, and local ordinances to reduce average annual pollutant loads. These Lake Tahoe TMDL implementation efforts will also reduce inputs of sediment to this impaired segment of Heavenly Valley Creek from the USFS boundary to Trout Creek. Additionally, the Lake Tahoe TMDL requires that the USFS-Lake Tahoe Basin Management Unit undertake restoration actions to reduce erosion and treat urban storm water runoff from paved and unpaved roadways, campgrounds, and recreational trails within the Lake Tahoe watershed. Storm water collection, conveyance, and treatment facilities coupled with revegetation of previously disturbed lands and stabilizing areas designated for recreational use are expected to reduce erosion and help control sediment discharges to Heavenly Valley Creek (USFS to Trout Creek). Finally, the Lake Tahoe TMDL also requires implementation of measures to control stationary sources of dust which help reduce pollutant loads of fine sediments. Implementation of these measures helps address the sedimentation/siltation loading that impairs Heavenly Valley Creek (USFS to Trout Creek) from dust sources. Pollutant load reductions within C will be tracked through implementation of detailed performance and compliance measures and assessment and reporting protocols included in the Lake Tahoe TMDL. The TMDL Management System project is establishing activity-based tracking and reporting requirements to assess activities that are expected to reduce pollutant loading from non-urban sources. The Lahontan Water Board and the Nevada Division of Environmental Protection will implement a Lake Tahoe TMDL Management System for managing, tracking, integrating and evaluating new information generated from TMDL implementation actions, effectiveness monitoring, research efforts, and other factors such as climate change and wildfires. The Management System is based on an adaptive management framework to (1) link load reduction effectiveness with project implementation monitoring to improve project design and to assess if actual environmental improvement is occurring as expected; (2) establish guidance and operation protocols for how new information will be incorporated into project designs and TMDL program implementation; (3) establish prioritized TMDL research needs to fill data gaps and reduce uncertainties, and (4) implement a process for updating and reporting pollutant load reduction estimates and tracking projects within the TMDL implementation timeline. The Lake Tahoe TMDL requires implementation, effectiveness, and status and trends monitoring. Tributary stream status and trends monitoring will track long-term changes in water quality conditions relative to established water quality standards or goals, and project-specific monitoring will be used to assess the efficacy of various implementation measures. Long-term water quality trends and pollutant load reduction tracking in Heavenly Valley Creek (USFS to Trout Creek) will be captured through the ongoing efforts of the Lake Tahoe Interagency Monitoring Program (LTIMP) whose primary objective is to monitor discharge, nutrient load, and sediment loads from representative streams that flow into Lake Tahoe. Nitrogen and phosphorus loading calculations are performed using the LTIMP flow and nutrient concentration database. LTIMP has monitored Heavenly Valley Creek (USFS to Trout Creek) and other tributaries to Lake Tahoe since 1988; this data is stored on the USGS website at http://wdr.water.usgs.gov/.

Regional Board Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

State Board Review of Regional Board Conclusion and Recommendation:	Pollutant load reductions within C will be tracked through implementation of detailed performance and compliance measures and assessment and reporting protocols included in the Lake Tahoe TMDL. The TMDL Management System project is establishing activity-based tracking and reporting requirements to assess activities that are expected to reduce pollutant loading from non-urban sources. The Lahontan Water Board and the Nevada Division of Environmental Protection will implement a Lake Tahoe TMDL Management System for managing, tracking, integrating and evaluating new information generated from TMDL implementation actions, effectiveness monitoring, research efforts, and other factors such as climate change and wildfires. The Management System is based on an adaptive management framework to (1) link load reduction effectiveness with project implementation monitoring to improve project design and to assess if actual environmental improvement is occurring as expected; (2) establish guidance and operation protocols for how new information will be incorporated into project designs and TMDL program implementation; (3) establish prioritized TMDL research needs to fill data gaps and reduce uncertainties, and (4) implement a process for updating and reporting pollutant load reduction estimates and tracking projects within the TMDL implementation timeline. The Lake Tahoe TMDL requires implementation, effectiveness, and status and trends monitoring. Tributary stream status and trends monitoring will track long-term changes in water quality conditions relative to established water quality standards or goals, and project-specific monitoring will be used to assess the efficacy of various implementation measures. Long-term water quality trends and pollutant load reduction tracking in Heavenly Valley Creek (USFS to Trout Creek) will be captured through the ongoing efforts of the Lake Tahoe Interagency Monitoring Program (LTIMP) whose primary objective is to monitor discharge, nutrient load, and sediment loads from representative streams that flow into Lake Tahoe. Nitrogen and phosphorus loading calculations are performed using the LTIMP flow and nutrient concentration database. LTIMP has monitored Heavenly Valley Creek (USFS to Trout Creek) and other tributaries to Lake Tahoe since 1988; this data is stored on the USGS website at http://wdr.water.usgs.gov/.

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 79971, Sedimentation/Siltation	Region 6
Heavenly Valley Creek (USFS boundary to Trout Creek)

LOE ID:

4617

Pollutant:

Sedimentation/Siltation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):