Water Turbidity

AUS-ASC-LVG-WTU General Moderate confidence

Benchmark Value

2 NTU
Direction: Lower is desirable ↓
Form: MaximumOnly

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

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard Point Guard

Evidence & Context

Proposed Lower Critical Threshold: ≤ 2 NTU (as a median or 50th percentile)

Metric Definition:

Water turbidity (median or 50th percentile)

Benchmark Definition:

This benchmark represents the maximum water turbidity level (median or 50th percentile) indicative of pristine or near-pristine alpine stream conditions, reflecting exceptional water clarity.

Justification:

Reflects conditions observed in minimally impacted alpine streams (e.g., Bullocks Head Creek) and represents exceptionally clear water.

Sources (1)

Preview of Natural Characteristics and Human Activity Influence Turbidity and Ion Concentrations in Streams - UCOWR, accessed July 18, 2025,
Natural Characteristics and Human Activity Influence Turbidity and Ion Concentrations in Streams - UCOWR, accessed July 18, 2025, Journal

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

View Source

Supporting Sources (14)

Additional references from the underlying research that informed this benchmark.

Preview of An Examination of Stream Water Quality Data from Monitoring of Forest Harvesting in the Eastern Highlands of Victoria - MDPI, accessed August 1, 2025,
An Examination of Stream Water Quality Data from Monitoring of Forest Harvesting in the Eastern Highlands of Victoria - MDPI, accessed August 1, 2025,
Contextual Support Journal

An Examination of Stream Water Quality Data from Monitoring of Forest Harvesting in the Eastern Highlands of Victoria.

View Source
Preview of Assessing Water Quality - Secondary Education Years 9 to 12 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,
Assessing Water Quality - Secondary Education Years 9 to 12 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,
Direct Evidence Journal

Assessing water quality - ACT Waterwatch.

View Source
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,
Contextual Support 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.

View Source
Preview of British Columbia Ministry of Environment. (2001). Summary of water quality guidelines for turbidity, suspended and benthic sediments.
British Columbia Ministry of Environment. (2001). Summary of water quality guidelines for turbidity, suspended and benthic sediments.
Contextual Support Government

British Columbia Ministry of Environment. (2001). Summary of water quality guidelines for turbidity, suspended and benthic sediments.

View Source
Preview of Feral horses (Equus caballus) increase suspended sediment in subalpine streams, accessed August 12, 2025,
Feral horses (Equus caballus) increase suspended sediment in subalpine streams, accessed August 12, 2025,
Direct Evidence Journal

Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management

View Source
Preview of Scanes, P., & Whitehead, A. (2019). Trigger values for New Zealand rivers: A comparison with south-eastern Australia. Ministry for the Environment, New Zealand.
Scanes, P., & Whitehead, A. (2019). Trigger values for New Zealand rivers: A comparison with south-eastern Australia. Ministry for the Environment, New Zealand.
Regulatory Framework Government

Scanes, P., & Whitehead, A. (2019). Trigger values for New Zealand rivers: A comparison with south-eastern Australia. Ministry for the Environment, New Zealand.

View Source
Preview of Snowy Strategic Activation Precinct - NSW Planning Portal
Snowy Strategic Activation Precinct - NSW Planning Portal
Contextual Support Journal

Department of Climate Change, Energy, the Environment and Water. (2006). Lowland Native Grasslands of Tasmania Listing Advice.

View Source
Preview of Sydney Drinking Water Catchment Audit 2019-22 - WaterNSW
Sydney Drinking Water Catchment Audit 2019-22 - WaterNSW
Direct Evidence Journal

Conservation land management aims to preserve ecological integrity and control erosion.9

View Source
Preview of theaustralianalpsnationalparks.org, accessed on May 28, 2025
theaustralianalpsnationalparks.org, accessed on May 28, 2025
Contextual Support Journal

Caring for our Australian Alps Catchments, accessed on May 28, 2025

View Source
Preview of Turbidity | Australian Drinking Water Guidelines - NHMRC, accessed August 11, 2025,
Turbidity | Australian Drinking Water Guidelines - NHMRC, accessed August 11, 2025,
Regulatory Framework Government

Turbidity | Australian Drinking Water Guidelines - NHMRC, accessed August 3, 2025

View Source
Preview of Turbidity in Surface Water 14 Rehabilitation Standard for the Ranger uranium mine - DCCEEW, accessed August 1, 2025,
Turbidity in Surface Water 14 Rehabilitation Standard for the Ranger uranium mine - DCCEEW, accessed August 1, 2025,
Regulatory Framework Government

ANZG (2018) Australian and New Zealand Guidelines for Fresh and Marine Water Quality

View Source
Preview of Victorian Water Quality Analysis 2022 Technical Report - Water and ..., accessed August 12, 2025,
Victorian Water Quality Analysis 2022 Technical Report - Water and ..., accessed August 12, 2025,
Contextual Support Journal

Victorian Water Quality Analysis 2022 Technical Report

View Source
Preview of Water quality of surface water environments - NSW Government Water, accessed August 1, 2025,
Water quality of surface water environments - NSW Government Water, accessed August 1, 2025,
Regulatory Framework Government

National Guidelines for Water Quality | Department of Natural ...

View Source
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,

View Source

Context

  • Region Australia
  • Biome Alpine and Subalpine Complex
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 2
  • Effective From 3 Jun 2026

Notes

Defined as a state of exceptional clarity reflecting minimal to no recent sediment input.

Related Benchmarks

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

10 NTU Moderate
Livestock Grazing & Pasture · Livestock Grazing & Pasture
MaximumOnly Active v2
5 NTU Moderate
Livestock Grazing & Pasture · Conservation Target
MaximumOnly Active v1
2 NTU Moderate
Livestock Grazing & Pasture · Pristine Reference
MaximumOnly Superseded v1
10 NTU Moderate
Livestock Grazing & Pasture · Livestock Grazing & Pasture
MaximumOnly Superseded v1