Water Turbidity

AUS-ASC-AQU-WTU General Moderate confidence

Benchmark Value

0 NTU

Direction: Lower is desirable ↓

Form: Point

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 15 benchmarks together — the OptimalRange form drives the primary score, while 14 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard Point Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

The lower critical threshold for water turbidity is 0 NTU. There are no documented detrimental effects associated with very low turbidity for salmonid health, growth, or productivity in a managed aquaculture system.

Metric Definition:

Water turbidity measured in NTU indicating the lowest turbidity level without detrimental effects on salmonid health in aquaculture.

Benchmark Definition:

This benchmark represents the lowest turbidity level considered non-detrimental for salmonid health in alpine aquaculture.

Justification:

Based on ecological literature and the natural state of pristine alpine streams, no negative effects are associated with turbidity approaching zero.

Sources (1)

Preview of Effects of Turbidity and Suspended Solids on Salmonids - ResearchGate

Effects of Turbidity and Suspended Solids on Salmonids - ResearchGate GreyLiterature

Effects of Turbidity and Suspended Solids on Salmonids - ResearchGate

Supporting Sources (39)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Climate change impacts on Australia's alpine ecosystems - ResearchGate, accessed on May 28, 2025,

(PDF) Climate change impacts on Australia's alpine ecosystems - ResearchGate, accessed on May 28, 2025,

Contextual Support GreyLiterature

(PDF) Climate change impacts on Australia's alpine ecosystems - ResearchGate, accessed August 5, 2025

Preview of Alpine Trout Farm

Alpine Trout Farm

Irrelevant

Alpine Trout Farm

Preview of Aquaculture in NSW facts & figures 2024

Aquaculture in NSW facts & figures 2024

Contextual Support Journal

Aquaculture in NSW facts & figures 2024, accessed August 10, 2025,

Preview of Australia: aquaculture exceeded the value of wild catch by 2021-22

Australia: aquaculture exceeded the value of wild catch by 2021-22

Contextual Support GreyLiterature

Australia: aquaculture exceeded the value of wild catch by 2021-22

Preview of Australia's Aquaculture industry - DAFF, accessed August 17, 2025,

Australia's Aquaculture industry - DAFF, accessed August 17, 2025,

Contextual Support Government

Australian fisheries and aquaculture outlook 2024 - DAFF

Preview of Australian and New Zealand guidelines for fresh and marine water quality, accessed July 19, 2025,

Australian and New Zealand guidelines for fresh and marine water quality, accessed July 19, 2025,

Regulatory Framework Government

Australian Alps Liaison Committee (AALC). (2011). Caring for our Australian Alps catchments: A climate change action strategy. Department of Climate Change and Energy Efficiency.

$Preview of C:\My Documents\BiOps and Notes\Milltown Dam\MTD Opinion\Appendix A.wpd - US EPA$

C:\My Documents\BiOps and Notes\Milltown Dam\MTD Opinion\Appendix A.wpd - US EPA

Contextual Support Journal

C:\My Documents\BiOps and Notes\Milltown Dam\MTD Opinion\Appendix A.wpd - US EPA

Preview of Caring for our Australian Alps Catchments, accessed August 28, 2025,

Caring for our Australian Alps Catchments, accessed August 28, 2025,

Contextual Support Journal

Patterns of variation in Australian alpine soils and their relationships to parent material, vegetation formation, climate and t, accessed May 27, 2025

Preview of Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin, accessed July 12, 2025,

Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin, accessed July 12, 2025,

Contextual Support Journal

Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin

Preview of Does turbidity determine fish growth? - American Fisheries Society

Does turbidity determine fish growth? - American Fisheries Society

Contextual Support GreyLiterature

Does turbidity determine fish growth? - American Fisheries Society

Preview of From Hatch to Catch - Buxton Trout & Salmon Farm's commitment to Sustainability since 1958.

From Hatch to Catch - Buxton Trout & Salmon Farm's commitment to Sustainability since 1958.

Contextual Support GreyLiterature

From Hatch to Catch - Buxton Trout & Salmon Farm's commitment to Sustainability since 1958.

Preview of Gaden Trout Hatchery - Away We Go Tours | School Excursions & Group Tours

Gaden Trout Hatchery - Away We Go Tours | School Excursions & Group Tours

Irrelevant

Gaden Trout Hatchery - Away We Go Tours | School Excursions & Group Tours

Preview of Gaden Trout Hatchery - Snowy Mountains Fishing

Gaden Trout Hatchery - Snowy Mountains Fishing

Irrelevant

Gaden Trout Hatchery - Snowy Mountains Fishing

Preview of Gaden Trout Hatchery - Thredbo River - Visit Cooma, accessed August 17, 2025,

Gaden Trout Hatchery - Thredbo River - Visit Cooma, accessed August 17, 2025,

Contextual Support Government

Gaden Trout Hatchery - Thredbo River - Visit Cooma

Preview of Gaden Trout Hatchery EPA Pollution Monitoring Data - August 2021

Gaden Trout Hatchery EPA Pollution Monitoring Data - August 2021

Direct Evidence Journal

Gaden Trout Hatchery EPA Pollution Monitoring Data - August 2021

Preview of Impacts of Sediment to Aquatic Habitats

Impacts of Sediment to Aquatic Habitats

Contextual Support Journal

Impacts of Sediment to Aquatic Habitats

Preview of Improved Methods for Correlating Turbidity and Suspended Solids for Monitoring - CLU-IN

Improved Methods for Correlating Turbidity and Suspended Solids for Monitoring - CLU-IN

Methodology Source Journal

Water-quality and ecosystem impacts of recreation in streams: Monitoring and management, accessed July 19, 2025,

Preview of Improvement of the Water Quality in Rainbow Trout Farming by Means of the Feeding Type and Management over 10 Years (2009–2019), accessed August 10, 2025

Improvement of the Water Quality in Rainbow Trout Farming by Means of the Feeding Type and Management over 10 Years (2009–2019), accessed August 10, 2025

Contextual Support Journal

Improvement of the Water Quality in Rainbow Trout Farming by Means of the Feeding Type and Management over 10 Years (2009–2019) - PMC

Preview of Lethal Turbidity Levels for Common Fish and Invertebrates in Auckland Streams - CiteSeerX

Lethal Turbidity Levels for Common Fish and Invertebrates in Auckland Streams - CiteSeerX

Contextual Support

Lethal Turbidity Levels for Common Fish and Invertebrates in Auckland Streams - CiteSeerX

Preview of Managing Recreational Trout Fisheries - VFA

Managing Recreational Trout Fisheries - VFA

Contextual Support Government

Managing Recreational Trout Fisheries - VFA

Preview of National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

Contextual Support

Using the ANZECC Guidelines and Water Quality Objectives in NSW

Preview of Remote Sensing Retrieval of Turbidity in Alpine Rivers based on high Spatial Resolution Satellites - MDPI

Remote Sensing Retrieval of Turbidity in Alpine Rivers based on high Spatial Resolution Satellites - MDPI

Methodology Source Journal

Remote Sensing Retrieval of Turbidity in Alpine Rivers based on high Spatial Resolution Satellites - MDPI

Preview of Review of water quality studies in the Australian Alps, accessed August 12, 2025,

Review of water quality studies in the Australian Alps, accessed August 12, 2025,

Contextual Support Government

Feral horses (Equus caballus) increase suspended sediment in subalpine streams

Preview of Snapshot of Australia's commercial fisheries and aquaculture - DAFF, accessed August 17, 2025,

Snapshot of Australia's commercial fisheries and aquaculture - DAFF, accessed August 17, 2025,

Contextual Support Government

Snapshot of Australia's commercial fisheries and aquaculture - DAFF

Preview of Snowy 2.0 Recreational Fishing Management Plan

Snowy 2.0 Recreational Fishing Management Plan

Contextual Support Journal

Snowy 2.0 Recreational Fishing Management Plan

Preview of Snowy Mountains Trout | freshtrout.com.au | Snowy Mountains Trout NSW

Snowy Mountains Trout | freshtrout.com.au | Snowy Mountains Trout NSW

Contextual Support GreyLiterature

About | Snowy Mountains Trout | freshtrout.com.au

Preview of Stony Creek Fish Farm

Stony Creek Fish Farm

Contextual Support GreyLiterature

Stony Creek Fish Farm

Preview of The conversion of Nephelometric Turbidity Units (NTU) into mg/l for Alberta Transportations turbidity specification is required

The conversion of Nephelometric Turbidity Units (NTU) into mg/l for Alberta Transportations turbidity specification is required

Methodology Source Journal

The conversion of Nephelometric Turbidity Units (NTU) into mg/l for Alberta Transportations turbidity specification is required

Preview of trout culture in recirculatory aquaculture system (ras) - National Fisheries Development Board

trout culture in recirculatory aquaculture system (ras) - National Fisheries Development Board

Contextual Support

trout culture in recirculatory aquaculture system (ras) - National Fisheries Development Board

Preview of Turbidity in freshwater habitats of Alaska - A review of published and unpublished literature relevant t

Turbidity in freshwater habitats of Alaska - A review of published and unpublished literature relevant t

Contextual Support Journal

Turbidity in freshwater habitats of Alaska - A review of published and unpublished literature relevant t

Preview of Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed August 11, 2025,

Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed August 11, 2025,

Contextual Support Journal

Reference-site data - Water Quality Australia

Preview of Water monitoring - NSW Department of Primary Industries, accessed August 17, 2025,

Water monitoring - NSW Department of Primary Industries, accessed August 17, 2025,

Contextual Support Government

Water monitoring - NSW Department of Primary Industries

Preview of Water Quality | Snowy Hydro

Water Quality | Snowy Hydro

Contextual Support Journal

Water Quality | Snowy Hydro

Preview of Water quality data and reports - EPA Victoria, accessed August 12, 2025,

Water quality data and reports - EPA Victoria, accessed August 12, 2025,

Contextual Support Government

Water quality data and reports - EPA Victoria

Preview of Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Contextual Support Government

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

Preview of Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025

Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025

Contextual Support Government

(PDF) Impact of mitigated forestry activities on turbidity: assessing ...

Preview of Water Quality Standards - Turbidity Technical Review - Oregon.gov, accessed August 11, 2025,

Water Quality Standards - Turbidity Technical Review - Oregon.gov, accessed August 11, 2025,

Contextual Support Journal

Positive responses of benthic macroinvertebrates to spatial and temporal reductions in water pollution downstream from a trout farm outlet | Knowledge and Management of Aquatic Ecosystems, accessed August 17, 2025

Preview of What is NTU? - TecnoConverting Engineering

What is NTU? - TecnoConverting Engineering

Contextual Support GreyLiterature

What is NTU? - TecnoConverting Engineering

Preview of www.environment.nsw.gov.au, accessed on May 25, 2025,

www.environment.nsw.gov.au, accessed on May 25, 2025,

Contextual Support

The Australian Alps Bioregion - Environment and Heritage, accessed on May 27, 2025,

Context

Region Australia
Biome Alpine and Subalpine Complex
Land Use Aquaculture
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Superseded
Version 1
Effective From 2 Jun 2026
Effective To 2 Jun 2026

Notes

Salmonids thrive in clear water conditions; no evidence supports a detrimental effect of very low turbidity. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-ASC-AQU-WTU family.