Water Turbidity

AUS-AMR-LVG-WTU General Moderate confidence

Benchmark Value

No specific value — see range

Range: 2 to 25 NTU

Thresholds: Lower: 2, Upper: 25

Optimal Range: 2 to 25

Direction: Lower is desirable ↓

Form: OptimalRange

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 2 benchmarks together — the OptimalRange form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard

Evidence & Context

The benchmark value of 2–25 NTU is the default trigger value range for this category.

Metric Definition:

Water Turbidity as the expected ambient (low-flow) turbidity range for ephemeral and intermittent streams in high-health, sustainably grazed catchments.

Benchmark Definition:

This benchmark represents the expected ambient (low-flow) turbidity range for ephemeral and intermittent streams in high-health, sustainably grazed catchments in the Arid Mountain Ranges & Uplands biome.

Justification:

It is derived by combining a weight of evidence from on-ground ecological assessments and national water quality guidelines. The SA EPA's 2022 assessment of the Flinders Ranges identified several creeks in "Good" ecological condition, characterized by healthy native vegetation and limited impact from stock. While direct turbidity data for these specific best-practice sites is unavailable, their ecological description aligns with the ANZECC (2000) definition of "slightly disturbed upland rivers."

Sources (1)

Preview of ANZECC & ARMCANZ (2000) guidelines - Water Quality Australia, accessed August 12, 2025

ANZECC & ARMCANZ (2000) guidelines - Water Quality Australia, accessed August 12, 2025 Government

ANZECC & ARMCANZ (2000) guidelines - Water Quality Australia

Supporting Sources (35)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) The Impact of Extreme Low Flows on the Water Quality of the Lower Murray River and Lakes (South Australia) - ResearchGate, accessed May 10, 2025,

(PDF) The Impact of Extreme Low Flows on the Water Quality of the Lower Murray River and Lakes (South Australia) - ResearchGate, accessed May 10, 2025,

Contextual Support Journal

Water in mining and industry

Preview of (PDF) Water quality in two Australian dryland rivers: spatial and temporal variability and the role of flow - ResearchGate, accessed July 30, 2025,

(PDF) Water quality in two Australian dryland rivers: spatial and temporal variability and the role of flow - ResearchGate, accessed July 30, 2025,

Contextual Support

(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

Preview of 1.5.2.1 Surface water - Bioregional Assessments |, accessed July 30, 2025,

1.5.2.1 Surface water - Bioregional Assessments |, accessed July 30, 2025,

Contextual Support Methodology Source Government

1.5.2.1 Surface water - Bioregional Assessments |, accessed July 30, 2025,

Preview of 3.2.4 Sediment exposure, accessed July 30, 2025,

3.2.4 Sediment exposure, accessed July 30, 2025,

Contextual Support Government

3.2.4 Sediment exposure, accessed July 30, 2025,

Preview of 5.5 Turbidity | Monitoring & Assessment - EPA Archives, accessed July 30, 2025,

5.5 Turbidity | Monitoring & Assessment - EPA Archives, accessed July 30, 2025,

Contextual Support Government

5.5 Turbidity | Monitoring & Assessment - EPA Archives, accessed August 3, 2025

Preview of An environmental flow to an ephemeral creek increases the input of carbon and nutrients to a downstream receiving river - Frontiers, accessed July 20, 2025

An environmental flow to an ephemeral creek increases the input of carbon and nutrients to a downstream receiving river - Frontiers, accessed July 20, 2025

Contextual Support Journal

Connectivity – New South Wales Irrigators' Council, accessed July 17, 2025

Preview of Characterising the relationship between water quality and water quantity, accessed August 5, 2025

Characterising the relationship between water quality and water quantity, accessed August 5, 2025

Contextual Support Journal

Report Card 2022-23 - EPA Victoria

Preview of Development of regional water quality and catchment guidelines for the conservation of aquatic ecosystems - NSW Environment Protection Authority, accessed July 30, 2025,

Development of regional water quality and catchment guidelines for the conservation of aquatic ecosystems - NSW Environment Protection Authority, accessed July 30, 2025,

Contextual Support Journal

Defining reference condition for South Australian streams ... - EPA SA, accessed August 3, 2025

Preview of Discover the Top 6 Benefits of Regenerative Farming in Australia, accessed August 5, 2025,

Discover the Top 6 Benefits of Regenerative Farming in Australia, accessed August 5, 2025,

Contextual Support GreyLiterature

The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF

Preview of Effects of Sedimentation and Turbidity on Lotic Food Webs: A Concise Review for Natural Resource Managers - ResearchGate, accessed July 16, 2025,

Effects of Sedimentation and Turbidity on Lotic Food Webs: A Concise Review for Natural Resource Managers - ResearchGate, accessed July 16, 2025,

Contextual Support

Effects of Sedimentation and Turbidity on Lotic Food Webs: A Concise Review for Natural Resource Managers - ResearchGate, accessed August 17, 2025

Preview of Exploring Stream Turbidity and Excess Sediment - Grand Valley State University, accessed July 30, 2025,

Exploring Stream Turbidity and Excess Sediment - Grand Valley State University, accessed July 30, 2025,

Contextual Support Journal

Exploring Stream Turbidity and Excess Sediment - Grand Valley State University, accessed July 30, 2025,

Preview of Grazing the surface of agricultural effects on water quality – impacts of in-stream cattle activity - RSC Blogs - The Royal Society of Chemistry, accessed July 30, 2025,

Grazing the surface of agricultural effects on water quality – impacts of in-stream cattle activity - RSC Blogs - The Royal Society of Chemistry, accessed July 30, 2025,

Contextual Support GreyLiterature

Grazing the surface of agricultural effects on water quality – impacts of in-stream cattle activity - RSC Blogs - The Royal Society of Chemistry, accessed July 30, 2025,

Preview of Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,

Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,

Contextual Support Journal

Guidance document for assessing and managing water quality in temporary waters, accessed July 10, 2025,

Preview of How has Australia's river water quality changed over two decades?, accessed July 30, 2025,

How has Australia's river water quality changed over two decades?, accessed July 30, 2025,

Contextual Support GreyLiterature

How has Australia's river water quality changed over two decades?, accessed July 30, 2025,

Preview of Impacts of Natural Land Loss on Water Quality - WeConservePA Library, accessed July 30, 2025,

Impacts of Natural Land Loss on Water Quality - WeConservePA Library, accessed July 30, 2025,

Contextual Support GreyLiterature

Impacts of Natural Land Loss on Water Quality - WeConservePA Library, accessed July 30, 2025,

Preview of Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics | Request PDF - ResearchGate, accessed July 30, 2025,

Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics | Request PDF - ResearchGate, accessed July 30, 2025,

Contextual Support Journal

Land-use effects on water quality in an intensively managed ...

Preview of Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Contextual Support GreyLiterature

Soil Health and Regenerative Agriculture - Southern Queensland Landscapes, accessed July 27, 2025,

Preview of Linking Sediment Dynamics, Riparian Vegetation and Aquatic Ecology in the Ovens River – Part 2 - La Trobe, accessed July 30, 2025,

Linking Sediment Dynamics, Riparian Vegetation and Aquatic Ecology in the Ovens River – Part 2 - La Trobe, accessed July 30, 2025,

Contextual Support

Linking Sediment Dynamics, Riparian Vegetation and Aquatic Ecology in the Ovens River – Part 2 - La Trobe, accessed July 30, 2025,

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 Direct Evidence

Australian and New Zealand Guidelines for Fresh and Marine Water ...

Preview of Northern and Yorke | Managing watercourses - Landscape South Australia, accessed July 30, 2025,

Northern and Yorke | Managing watercourses - Landscape South Australia, accessed July 30, 2025,

Contextual Support Government

Northern and Yorke | Managing watercourses - Landscape South Australia, accessed July 30, 2025,

Preview of Nutrient Criteria Technical Guidance Manual: Rivers and Streams - Environmental Protection Agency (EPA), accessed July 30, 2025

Nutrient Criteria Technical Guidance Manual: Rivers and Streams - Environmental Protection Agency (EPA), accessed July 30, 2025

Contextual Support Journal

Nutrient Criteria Technical Guidance Manual: Rivers and Streams - Environmental Protection Agency (EPA), accessed August 17, 2025,

Preview of Preliminary information for developing sediment guidelines for streams of the West Coast, New Zealand - Envirolink, accessed August 17, 2025,

Preliminary information for developing sediment guidelines for streams of the West Coast, New Zealand - Envirolink, accessed August 17, 2025,

Contextual Support Journal

Preliminary information for developing sediment guidelines for streams of the West Coast, New Zealand - Envirolink, accessed August 1, 2025,

Preview of Queensland Murray-Darling Freshwater Biogeographic Province 6 Water quality - WetlandInfo, accessed July 16, 2025,

Queensland Murray-Darling Freshwater Biogeographic Province 6 Water quality - WetlandInfo, accessed July 16, 2025,

Contextual Support Government

Queensland Murray-Darling Freshwater Biogeographic Province – Water quality - WetlandInfo

Preview of Reducing the impacts of grazing on water quality - EPA Victoria, accessed August 8, 2025

Reducing the impacts of grazing on water quality - EPA Victoria, accessed August 8, 2025

Contextual Support Journal

Generic document, accessed July 19, 2025,

Preview of Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Contextual Support Journal

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 28, 2025,

Preview of Requirements for graziers | Environment, land and water | Queensland Government, accessed July 30, 2025,

Requirements for graziers | Environment, land and water | Queensland Government, accessed July 30, 2025,

Contextual Support Government

Soil Health & Your Wealth - presented by Graeme Sait - Regional Development Australia, accessed July 30, 2025,

Preview of SA Arid Lands Landscape Regional Summary 2022 Aquatic ..., accessed July 30, 2025,

SA Arid Lands Landscape Regional Summary 2022 Aquatic ..., accessed July 30, 2025,

Contextual Support Government

(PDF) Effects of increasing salinity on freshwater ecosystems in ..., accessed July 31, 2025,

Preview of Sediments | AIMS - The Australian Institute of Marine Science, accessed July 30, 2025,

Sediments | AIMS - The Australian Institute of Marine Science, accessed July 30, 2025,

Contextual Support Government

Sediments | AIMS - The Australian Institute of Marine Science, accessed July 30, 2025,

Preview of Sustainable land management practices for graziers - NSW Department of Primary Industries, accessed August 8, 2025

Sustainable land management practices for graziers - NSW Department of Primary Industries, accessed August 8, 2025

Contextual Support Government

Sustainable land management practices for graziers - NSW Department of Primary Industries, accessed August 8, 2025

Preview of Water quality | Australia state of the environment 2021, accessed August 11, 2025,

Water quality | Australia state of the environment 2021, accessed August 11, 2025,

Contextual Support Government

Drivers of water quality in Afromontane-savanna rivers - Frontiers

Preview of Water quality and the grazing animal - PubMed, accessed July 30, 2025,

Water quality and the grazing animal - PubMed, accessed July 30, 2025,

Contextual Support Journal

Water quality and the grazing animal - PubMed, accessed July 10, 2025,

Preview of Water quality for farm water supplies | Managing dams - Agriculture Victoria, accessed August 1, 2025,

Water quality for farm water supplies | Managing dams - Agriculture Victoria, accessed August 1, 2025,

Contextual Support Government

Water quality for farm water supplies | Managing dams - Agriculture Victoria, accessed August 1, 2025,

Preview of Water quality for primary industries, accessed July 30, 2025,

Water quality for primary industries, accessed July 30, 2025,

Contextual Support Government

Development of regional water quality and catchment guidelines for the conservation of aquatic ecosystems - NSW Environment Protection Authority

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 WESTERN AUSTRALIAN WATER QUALITY GUIDELINES FOR FRESH AND MARINE WATERS - DBCA Library, accessed July 16, 2025,

WESTERN AUSTRALIAN WATER QUALITY GUIDELINES FOR FRESH AND MARINE WATERS - DBCA Library, accessed July 16, 2025,

Contextual Support Journal

WESTERN AUSTRALIAN WATER QUALITY ... - DBCA Library, accessed July 25, 2025,

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Livestock Grazing & Pasture
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 16 Mar 2026

Notes

The benchmark applies to the crucial low-flow or baseflow conditions in refugial waterholes, not to naturally turbid high-flow events. Sustained turbidity above 25 NTU is considered detrimental due to reduced light penetration, which suppresses primary production and smothers habitat. Studies show significant negative impacts on algae and invertebrates at levels as low as 9–19 NTU. The concept of a lower critical threshold where water is "too clean" is not supported; arid streams naturally transport sediment and organic matter essential for ecosystem function.

Related Benchmarks

Other benchmarks in the AUS-AMR-LVG-WTU family.