Water Turbidity

AUS-TSR-LVG-WTU General Moderate confidence

Benchmark Value

15 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

Once baseflow turbidity consistently exceeds 15–20 NTU, significant negative impacts on a range of aquatic life and ecosystem functions are highly probable.

Metric Definition:

Water turbidity measured as Nephelometric Turbidity Units (NTU) indicating onset of significant ecological harm.

Benchmark Definition:

This benchmark marks the turbidity level above which significant ecological harm is likely in tropical rainforest grazing landscapes.

Justification:

Synthesized from multiple studies indicating ecological harm above this turbidity level.

Sources (1)

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, Journal

Assessing water quality - ACT Waterwatch.

View Source

Supporting Sources (23)

Additional references from the underlying research that informed this benchmark.

(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed August 2, 2025,

Contextual Support GreyLiterature

Ecology of streams in a biogeographic isolate 6the Queensland Wet Tropics, Australia, accessed July 21, 2025

View Source

(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed July 19, 2025,

Contextual Support Journal

Climate change and its implications for Australia´s freshwater fish - CSIRO Publishing, accessed July 19, 2025,

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Preview of A Compendium of Ecological Information on Australia's Northern Tropical Rivers - Report 5 - Water quality - DCCEEW, accessed August 1, 2025,

A Compendium of Ecological Information on Australia's Northern Tropical Rivers - Report 5 - Water quality - DCCEEW, accessed August 1, 2025,

Contextual Support Journal

Threshold Indicator Taxa ANalysis and change points (dots) for the ...

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A meta-analytical review of turbidity effects on fish mobility - ResearchGate, accessed July 24, 2025

Contextual Support Journal

A meta-analytical review of turbidity effects on fish mobility - ResearchGate, accessed July 19, 2025,

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Backgrounder: Impact of land runoff | AIMS - The Australian Institute of Marine Science, accessed May 11, 2025,

Contextual Support Government

Backgrounder: Impact of land runoff | AIMS, accessed July 19, 2025,

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Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - ResearchGate, accessed July 19, 2025,

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - ResearchGate, accessed July 19, 2025,

Contextual Support Journal

View Source

Preview of Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - CSIRO Research Publications Repository

Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - CSIRO Research Publications Repository

Direct Evidence Journal

(PDF) A review of the salt sensitivity of the Australian freshwater biota

View Source

Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - ResearchOnline@JCU, accessed July 19, 2025,

Direct Evidence Journal

Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - ResearchOnline@JCU, accessed July 19, 2025,

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Grazing Best Practice

Contextual Support GreyLiterature

Grazing Best Practice

View Source

Preview of Hillslope gully erosion in savanna rangelands tributary to the Great Barrier Reef: Investigation of hydrogeomorphic processes - USC Research Bank, accessed July 22, 2025,

Hillslope gully erosion in savanna rangelands tributary to the Great Barrier Reef: Investigation of hydrogeomorphic processes - USC Research Bank, accessed July 22, 2025,

Direct Evidence Journal

Hillslope gully erosion in savanna rangelands tributary to the Great Barrier Reef: Investigation of hydrogeomorphic processes, sediment and nutrient yields (PhD Thesis)

View Source

Impacts of improved grazing land management on sediment yields, Part 1: Hillslope processes - ResearchGate, accessed July 19, 2025,

Contextual Support Journal

Impacts of improved grazing land management on sediment yields, Part 1: Hillslope processes - ResearchGate, accessed July 19, 2025,

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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,

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Land management for graziers | Business Queensland, accessed August 8, 2025

Contextual Support Government

Managing Gully Erosion - NQ Dry Tropics

View Source

Mutual relationships of suspended sediment, turbidity and visual clarity in New Zealand rivers - PIAHS, accessed July 19, 2025,

Contextual Support Journal

Mutual relationships of suspended sediment, turbidity and visual clarity in New Zealand rivers - PIAHS, accessed July 19, 2025,

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Natural water systems | Australia state of the environment 2021, accessed July 16, 2025,

Contextual Support Government

Characterising the relationship between water quality and water quantity, accessed July 16, 2025

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

Contextual Support Journal

Grazing water quality risk framework 2017-2022, accessed July 10, 2025,

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Total-Suspended-Solids-from-Turbidity-Tech-Note.pdf - In-Situ, accessed July 19, 2025,

Methodology Source Journal

Total-Suspended-Solids-from-Turbidity-Tech-Note.pdf - In-Situ, accessed July 19, 2025,

View Source

Turbidity-based erosion estimation in a catchment in South Australia - ResearchGate, accessed July 19, 2025,

Methodology Source Journal

Turbidity-based erosion estimation in a catchment in South Australia - ResearchGate, accessed July 19, 2025,

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

Contextual Support Journal

Reference-site data - Water Quality Australia

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Water quality for livestock, accessed July 29, 2025,

Contextual Support Journal

Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers, accessed July 10, 2025,

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Water Quality Guidelines for the Great Barrier Reef Marine Park.

Direct Evidence Journal

Water Quality Guidelines for the Great Barrier Reef Marine Park.

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Water quality of surface water environments - NSW Government Water, accessed August 1, 2025,

Contextual Support Government

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

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Water-quality and ecosystem impacts of recreation in streams: Monitoring and management, accessed July 22, 2025

Contextual Support Journal

Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed July 19, 2025,

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Livestock Grazing & Pasture
Assessment Conservation Target
Season Baseflow conditions
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Represents a conservative threshold for high environmental health in grazing landscapes.

Related Benchmarks

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