Water Turbidity

AUS-AIF-IND-WTU General Moderate confidence

Benchmark Value

25 NTU

Direction: Lower is desirable ↓

Form: MinimumOnly

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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MinimumOnly Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard

Evidence & Context

Lower Critical Threshold: No specific numerical threshold is supported by the literature. However, an artificially low turbidity (e.g., consistently below 25 NTU) would signify a profoundly altered and ecologically degraded state.

Metric Definition:

Lower critical threshold turbidity value below which ecological degradation is indicated.

Benchmark Definition:

This benchmark indicates the turbidity level below which water clarity is unnaturally high, signaling ecological degradation due to disrupted sediment and nutrient transport in arid ephemeral river systems.

Justification:

Literature supports that turbidity below this level indicates disruption of natural sediment and nutrient transport processes.

Sources (1)

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, Government

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

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Supporting Sources (13)

Additional references from the underlying research that informed this benchmark.

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

Irrelevant Government

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

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Assessing Water Quality - Secondary Education Years 9 to 12 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,

Contextual Support Journal

Assessing water quality - ACT Waterwatch.

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

Contextual Support Journal

Turbidity | Australia state of the environment 2021

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Environment Monitoring Systems & Data for Ecosystem Studies ..., accessed July 30, 2025,

Contextual Support Government

(PDF) Evaluation of genetic markers for the metabarcoding of ...

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Evaluating Water Management Practice for Sustainable Mining - MDPI, accessed July 20, 2025

Contextual Support Journal

Evaluating Water Management Practice for Sustainable Mining - MDPI, accessed July 20, 2025

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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

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Preview of Persistence of in-stream waterholes in ephemeral rivers of tropical northern Australia and potential impacts of climate change - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 18, 2025,

Persistence of in-stream waterholes in ephemeral rivers of tropical northern Australia and potential impacts of climate change - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 18, 2025,

Contextual Support Journal

Persistence of in-stream waterholes in ephemeral rivers of tropical northern Australia and potential impacts of climate change - CSIRO PUBLISHING | Marine and Freshwater Research

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Turbidity | Australian Drinking Water Guidelines - NHMRC, accessed August 11, 2025,

Contextual Support Government

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

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Water Management in the Australian Minerals Industry - UQ eSpace - The University of Queensland, accessed July 20, 2025

Contextual Support Journal

Water Management in the Australian Minerals Industry - UQ eSpace - The University of Queensland, accessed July 20, 2025

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Water management in the Pilbara – time for a more strategic approach?

Contextual Support Journal

WATER STEWARDSHIP - Leading Practice Sustainable ..., accessed July 20, 2025

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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)

View Source

WATER STEWARDSHIP - Leading Practice Sustainable ..., accessed July 24, 2025

Direct Evidence Journal

(PDF) Water quality in two Australian dryland rivers: spatial and ..., accessed July 20, 2025

View Source

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,

View Source

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Industrial & Infrastructure Use
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 3 Jun 2026

Notes

Artificially low turbidity is an indicator of poor ecological health in this biome, often caused by upstream dams or impoundments. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AIF-IND-WTU family.