Water Turbidity

AUS-ASC-LVG-WTU General Moderate confidence

Benchmark Value

5 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.

Evidence & Context

"Ideally, samples should have <5 NTU turbidity. In such streams, turbidity can be used as a general measure of sediment and soil contamination"

Metric Definition:

Nephelometric turbidity measured in mountain streams to assess suitability for sensitive native fish species and identify early land degradation.

Benchmark Definition:

Upper limit turbidity target for pristine conditions in forested mountain streams to maintain critical cold-water fish habitat.

Justification:

This benchmark is tailored for high-gradient, shallow, gravel-bottomed mountain streams in southeastern Australia. A target of <5 NTU represents the ideal real-world ecological condition achievable under strict soil conservation and sustainable land-use management.

Sources (1)

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, Journal

A large data set measuring surface stream turbidity, dissolved oxygen levels, and water temperature

Supporting Sources (16)

Additional references from the underlying research that informed this benchmark.

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.

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.

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.

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

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,

Direct Evidence Journal

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

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.

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.

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

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

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

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

Preview of Victorian Water Quality Analysis 2022 – Summary Report, accessed August 10, 2025,

Victorian Water Quality Analysis 2022 – Summary Report, accessed August 10, 2025,

Direct Evidence Journal

Surface water hydrology and water quality - Gippsland Basin bioregion

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

Preview of Water Quality Objectives - Belconnen Trunk Sewer Augmentation Volume 2 Technical Papers

Water Quality Objectives - Belconnen Trunk Sewer Augmentation Volume 2 Technical Papers

Irrelevant

Water Quality Objectives - Belconnen Trunk Sewer Augmentation Volume 2 Technical Papers

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 ...

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 Livestock Grazing & Pasture
Assessment Conservation Target
Vegetation Forest
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 16 Jun 2026

Notes

This value represents the upper limit of pristine conditions; values above 5 NTU indicate initial sediment contamination or soil disturbance from catchment activities.

Related Benchmarks

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