Water Turbidity

AUS-TSR-AGR-WTU General Moderate confidence

Benchmark Value

No specific value — see range

Range: 2.5 to 5 NTU

Thresholds: Lower: —, Upper: 6

Optimal Range: 2.5 to 5

Direction: Higher 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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Water Turbidity 2.5 - 6 NTU (baseflow conditions) NTU Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Volume 2, Chapter 8 High The benchmark is based on the ANZECC (2000) default trigger values for tropical Australian rivers, derived from minimally disturbed reference catchments.

Metric Definition:

Water turbidity is a measure of water clarity, quantifying the degree to which light is scattered by suspended particles in the water column.

Benchmark Definition:

This benchmark represents the range of water turbidity levels considered optimal for tropical and subtropical rainforest streams under agricultural crop production, based on minimally disturbed reference catchments. Maintaining turbidity within this range supports healthy aquatic ecosystems by minimizing sediment and erosion impacts.

Justification:

The benchmark is based on the ANZECC (2000) default trigger values for tropical Australian rivers, derived from minimally disturbed reference catchments. This is used as a robust proxy for the 'best available condition' under regenerative agriculture, as the explicit goal of such practices is to minimize erosion and sediment loss, thereby restoring the stream's water quality to a state that mimics a healthy, stable, natural catchment.

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 (51)

Additional references from the underlying research that informed this benchmark.

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

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

Contextual Support

Requirements for graziers | Environment, land and water ..., accessed July 19, 2025,

Preview of Altered water flows and quality | Wet Tropics Management Authority, accessed July 18, 2025,

Altered water flows and quality | Wet Tropics Management Authority, accessed July 18, 2025,

Contextual Support Government

Declining water quality - Reef Authority

Preview of ANZEC Guidelines - Risk Assessment for Contaminated Sites in New Zealand, accessed July 18, 2025,

ANZEC Guidelines - Risk Assessment for Contaminated Sites in New Zealand, accessed July 18, 2025,

Contextual Support Regulatory Framework Government

Salinity - Murray–Darling Basin Authority, accessed July 31, 2025,

Preview of Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) - Consultas Ciudadanas, accessed May 11, 2025,

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) - Consultas Ciudadanas, accessed May 11, 2025,

Direct Evidence Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) - Consultas Ciudadanas, accessed May 11, 2025,

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

Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed July 21, 2025,

Preview of Best Management Practice Programs - Queensland Farmers' Federation, accessed July 18, 2025,

Best Management Practice Programs - Queensland Farmers' Federation, accessed July 18, 2025,

Contextual Support

Best Management Practice Programs - Queensland Farmers' Federation, accessed July 18, 2025,

Preview of Best management practice programs in Reef catchments - Australia's Nature Hub, accessed July 18, 2025,

Best management practice programs in Reef catchments - Australia's Nature Hub, accessed July 18, 2025,

Contextual Support Government

Best management practice programs in Reef catchments - Australia's Nature Hub, accessed July 18, 2025,

Preview of Best practice farming in Great Barrier Reef catchments | Business ..., accessed July 25, 2025,

Best practice farming in Great Barrier Reef catchments | Business ..., accessed July 25, 2025,

Contextual Support Government

Best practice farming in Great Barrier Reef catchments | Business Queensland, accessed July 20, 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 CLARITY AND TURBIDITY - New Jersey Sea Grant Consortium, accessed July 18, 2025,

CLARITY AND TURBIDITY - New Jersey Sea Grant Consortium, accessed July 18, 2025,

Contextual Support Journal

CLARITY AND TURBIDITY - New Jersey Sea Grant Consortium, accessed July 18, 2025,

Preview of Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management - PubMed Central, accessed July 16, 2025,

Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management - PubMed Central, accessed July 16, 2025,

Contextual Support Direct Evidence Journal

Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management. Water, 15(8), 1589.

Preview of Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef, accessed August 3, 2025,

Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef, accessed August 3, 2025,

Contextual Support Journal

Lewis, S. E., et al. (2017). Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef. Reef Water Quality Protection Plan. 41

Preview of development of ecosystem health bottom-line thresholds for suspended and deposited sediment in New Zealand rivers and streams - Ministry for the Environment, accessed July 16, 2025,

development of ecosystem health bottom-line thresholds for suspended and deposited sediment in New Zealand rivers and streams - Ministry for the Environment, accessed July 16, 2025,

Contextual Support Journal

development of ecosystem health bottom-line thresholds for suspended and deposited sediment in New Zealand rivers and streams - Ministry for the Environment

Preview of Ecological aspects of water impoundment in the tropics by, accessed July 18, 2025,

Ecological aspects of water impoundment in the tropics by, accessed July 18, 2025,

Contextual Support Journal

Ecological aspects of water impoundment in the tropics by, accessed July 18, 2025,

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

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

Contextual Support Journal

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

Preview of Effects of suspended solids on benthic macroinvertebrate fauna downstream of a road crossing, Jim Jim Creek, Kakadu - DCCEEW, accessed July 21, 2025,

Effects of suspended solids on benthic macroinvertebrate fauna downstream of a road crossing, Jim Jim Creek, Kakadu - DCCEEW, accessed July 21, 2025,

Contextual Support Direct Evidence

Riparian Ecological Restoration Guidelines - Friends of Berowra Valley Inc.

Preview of Environmental Protection (Water) Policy 2009 - Queensland Legislation, accessed July 18, 2025,

Environmental Protection (Water) Policy 2009 - Queensland Legislation, accessed July 18, 2025,

Regulatory Framework Journal

Environmental Protection (Water) Policy 2009 - Queensland Legislation, accessed July 18, 2025,

Preview of Environmental Protection (Water) Policy 2009 Ross River Basin and Magnetic Island Environmental Values and Water Quality Objecti - Queensland Environment Department, accessed July 18, 2025,

Environmental Protection (Water) Policy 2009 Ross River Basin and Magnetic Island Environmental Values and Water Quality Objecti - Queensland Environment Department, accessed July 18, 2025,

Regulatory Framework Journal

Environmental Protection (Water) Policy 2009 Ross River Basin and Magnetic Island Environmental Values and Water Quality Objecti - Queensland Environment Department, accessed July 18, 2025,

Preview of Improving Water Quality in the Wet Tropics, Australia: A Conceptual Framework and Case Study - MDPI, accessed July 18, 2025,

Improving Water Quality in the Wet Tropics, Australia: A Conceptual Framework and Case Study - MDPI, accessed July 18, 2025,

Contextual Support Journal

NSW Land Based Sustainable Aquaculture Strategy, accessed July 21, 2025,

Preview of Land-based run-off - Reef Authority, accessed July 19, 2025,

Land-based run-off - Reef Authority, accessed July 19, 2025,

Contextual Support Government

Land-based run-off - Reef Authority,

Preview of Landholder stories | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Landholder stories | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Contextual Support Government

Landholder stories | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Preview of Marine ecosystem impacts - Reef 2050 Water Quality Improvement Plan, accessed August 1, 2025,

Marine ecosystem impacts - Reef 2050 Water Quality Improvement Plan, accessed August 1, 2025,

Contextual Support Journal

TERN: Terrestrial Ecosystem Research Network - The Waite, accessed July 27, 2025,

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,

Contextual Support Journal

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

Preview of Paddock to Reef | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Paddock to Reef | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Contextual Support Government

Paddock to Reef | Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Preview of Paddock to Reef Integrated Monitoring, Modelling and Reporting Program Summary, accessed July 18, 2025,

Paddock to Reef Integrated Monitoring, Modelling and Reporting Program Summary, accessed July 18, 2025,

Contextual Support Journal

Paddock to Reef Integrated Monitoring, Modelling and Reporting Program Summary, accessed July 18, 2025,

Preview of Paddock to Reef Monitoring, Modelling and Reporting Program, accessed July 18, 2025,

Paddock to Reef Monitoring, Modelling and Reporting Program, accessed July 18, 2025,

Contextual Support Government

Paddock to Reef Monitoring, Modelling and Reporting Program, accessed July 18, 2025,

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

Preview of Reef regulations and Best Management Practice programs factsheet, accessed July 18, 2025,

Reef regulations and Best Management Practice programs factsheet, accessed July 18, 2025,

Contextual Support Journal

Reef regulations and Best Management Practice programs factsheet - Queensland Government, accessed July 20, 2025,

Preview of Reef water quality and regional report cards - Fitzroy Partnership for River Health, accessed July 18, 2025,

Reef water quality and regional report cards - Fitzroy Partnership for River Health, accessed July 18, 2025,

Contextual Support Journal

Reef water quality and regional report cards - Fitzroy Partnership for River Health, accessed July 18, 2025,

Preview of Reef Water Quality Report Card 2019 Agricultural land management practice adoption methods, accessed July 18, 2025,

Reef Water Quality Report Card 2019 Agricultural land management practice adoption methods, accessed July 18, 2025,

Contextual Support Journal

Reef Water Quality Report Card 2019 Agricultural land management practice adoption methods, accessed July 18, 2025,

Preview of Regenerative farming practices to improve Great Barrier Reef water quality - Australian Circular Economy Hub, accessed July 18, 2025,

Regenerative farming practices to improve Great Barrier Reef water quality - Australian Circular Economy Hub, accessed July 18, 2025,

Contextual Support GreyLiterature

GROWER CASE STUDY ON ECONOMICS OF AN IMPROVED ...

Preview of Responses of Phytoplanktonic Chlorophyll-a Composition to Inorganic Turbidity Caused by Mine Tailings - Frontiers, accessed July 18, 2025,

Responses of Phytoplanktonic Chlorophyll-a Composition to Inorganic Turbidity Caused by Mine Tailings - Frontiers, accessed July 18, 2025,

Contextual Support Journal

Responses of Phytoplanktonic Chlorophyll-a Composition to Inorganic Turbidity Caused by Mine Tailings - Frontiers, accessed July 18, 2025,

Preview of Reviews and syntheses: Dams, water quality and tropical reservoir stratification - BG, accessed July 18, 2025,

Reviews and syntheses: Dams, water quality and tropical reservoir stratification - BG, accessed July 18, 2025,

Contextual Support Journal

Reviews and syntheses: Dams, water quality and tropical reservoir stratification - BG, accessed July 18, 2025,

Preview of Science in Water Quality - Reef & Rainforest Research Centre, accessed August 2, 2025,

Science in Water Quality - Reef & Rainforest Research Centre, accessed August 2, 2025,

Contextual Support

Science in Water Quality - Reef & Rainforest Research Centre, accessed July 22, 2025,

Preview of Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy - PMC, accessed July 18, 2025,

Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy - PMC, accessed July 18, 2025,

Contextual Support Journal

Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy - PMC, accessed July 18, 2025,

Preview of The influence of riparian vegetation on water quality in a mixed land use river basin - UQ eSpace, accessed July 18, 2025,

The influence of riparian vegetation on water quality in a mixed land use river basin - UQ eSpace, accessed July 18, 2025,

Contextual Support Journal

Queensland Aquaculture Strategy 2024–2034, accessed July 21, 2025

Preview of Treatment systems for agriculture – Farm and waterway best ..., accessed July 18, 2025,

Treatment systems for agriculture – Farm and waterway best ..., accessed July 18, 2025,

Contextual Support Government

Treatment systems for agriculture Farm and waterway best management practices, accessed August 10, 2025

Preview of Turbidity | River Detectives, accessed July 16, 2025,

Turbidity | River Detectives, accessed July 16, 2025,

Contextual Support Journal

Turbidity | River Detectives, accessed July 27, 2025,

Preview of Turbidity measurement and monitoring in water quality analysis, accessed July 18, 2025,

Turbidity measurement and monitoring in water quality analysis, accessed July 18, 2025,

Methodology Source GreyLiterature

Turbidity measurement and monitoring in water quality analysis, accessed July 16, 2025,

Preview of Turbidity Monitoring and Reduction - NTU, accessed July 18, 2025,

Turbidity Monitoring and Reduction - NTU, accessed July 18, 2025,

Contextual Support GreyLiterature

Turbidity Monitoring and Reduction - NTU, accessed July 18, 2025,

Preview of tuvalu-data.sprep.org, accessed May 11, 2025,

tuvalu-data.sprep.org, accessed May 11, 2025,

Direct Evidence Journal

Palaeovalley Groundwater Resources in Arid and Semi-Arid Australia - Geoscience Australia, accessed July 31, 2025,

Preview of Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Regulatory Framework Government

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

Preview of Water Quality Guidelines for the Great Barrier Reef Marine Park., accessed August 3, 2025,

Water Quality Guidelines for the Great Barrier Reef Marine Park., accessed August 3, 2025,

Contextual Support Direct Evidence Journal

Great Barrier Reef Marine Park Authority (GBRMPA). (2010). Water Quality Guidelines for the Great Barrier Reef Marine Park. Rev. ed. 35

Preview of Water Quality Monitoring, accessed July 18, 2025,

Water Quality Monitoring, accessed July 18, 2025,

Methodology Source Journal

Water Quality Monitoring, accessed July 18, 2025,

Preview of Water-quality and ecosystem impacts of recreation in streams: Monitoring and management, accessed August 1, 2025,

Water-quality and ecosystem impacts of recreation in streams: Monitoring and management, accessed August 1, 2025,

Contextual Support Journal

Water-quality and ecosystem impacts of recreation in streams: Monitoring and management, accessed July 18, 2025,

Preview of Wet Tropics - Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Wet Tropics - Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Contextual Support Government

Wet Tropics - Reef 2050 Water Quality Improvement Plan, accessed July 18, 2025,

Preview of Wet Tropics farmers improve local water quality - Great Barrier Reef ..., accessed July 18, 2025,

Wet Tropics farmers improve local water quality - Great Barrier Reef ..., accessed July 18, 2025,

Contextual Support GreyLiterature

Wet Tropics farmers improve local water quality - Great Barrier Reef ..., accessed July 18, 2025,

Preview of wet tropics report card 2024 - waterway environment results, accessed August 2, 2025,

wet tropics report card 2024 - waterway environment results, accessed August 2, 2025,

Contextual Support GreyLiterature

Report Card - Wet Tropics Waterways, accessed August 2, 2025,

Preview of wet tropics report card 2024 - waterway environment results, accessed July 18, 2025,

wet tropics report card 2024 - waterway environment results, accessed July 18, 2025,

Contextual Support

wet tropics report card 2024 - waterway environment results, accessed July 18, 2025

Preview of Why Measure Turbidity? - Montclair State University, accessed August 12, 2025,

Why Measure Turbidity? - Montclair State University, accessed August 12, 2025,

Contextual Support GreyLiterature

Feral horses (Equus caballus) increase suspended sediment in subalpine streams, accessed August 3, 2025

Preview of WQIP - Water Quality Improvement Plan - Wet Tropics Plan, accessed July 18, 2025,

WQIP - Water Quality Improvement Plan - Wet Tropics Plan, accessed July 18, 2025,

Regulatory Framework Government

Queensland Aquaculture Strategy 2024–2034

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Agricultural Crop Production
Assessment Conservation Target
Vegetation Forest
Season dry season baseflow conditions
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 15 Mar 2026

Notes

No evidence supports a detrimental lower threshold; low turbidity is consistently the goal of best practice. An upper detrimental threshold exists with sublethal stress to corals at >3 NTU and significant impacts on sensitive freshwater invertebrates at >5 NTU, indicating a clear ecological tipping point. The optimal condition is to maintain turbidity at or below these reference benchmark values. RangeFixup applied 2026-03-21 22:21 UTC: OptimalRangeHigh: 6 → 5; UpperThreshold: 5 → 6 [Migration] Original wider evidence range: 2.5 – 6 (retained OptimalRange: 2.5 – 5)