Water Turbidity

AUS-TGP-FOR-WTU General Moderate confidence

Benchmark Value

25 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 11 benchmarks together — the OptimalRange form drives the primary score, while 10 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary UpperThreshold Guard OptimalRange Guard UpperThreshold Guard MaximumOnly Guard OptimalRange Guard OptimalRange Guard MaximumOnly Guard Point Guard OptimalRange Guard MaximumOnly Guard

Evidence & Context

A persistent median or baseline turbidity > 25 NTU can be defined as the upper detrimental threshold for this context.

Metric Definition:

Water turbidity as a measure of water clarity and suspended particulate matter in water.

Benchmark Definition:

This benchmark defines the upper detrimental threshold for water turbidity in production forestry catchments within the Temperate Grassy Woodlands & Plains biome in Australia, indicating ecological degradation.

Justification:

This threshold aligns with the upper bound of ANZECC guidelines and indicates a transition from an acceptable, temporary operational impact to a state of chronic degradation.

Sources (1)

Preview of Water Quality Objectives - Border Rivers - NSW Government
Water Quality Objectives - Border Rivers - NSW Government Government

Water Quality Objectives - Border Rivers - NSW Government

View Source

Supporting Sources (15)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Determining reference conditions for management and ..., accessed August 5, 2025,
(PDF) Determining reference conditions for management and ..., accessed August 5, 2025,
Contextual Support Journal

Effects of Stock Grazing on Biodiversity Values in Temperate Native Grasslands and Grassy Woodlands in SE Australia: A Literature Review - ACT Government

View Source
Preview of Best Management Practices - National Association of State Foresters, accessed July 12, 2025,
Best Management Practices - National Association of State Foresters, accessed July 12, 2025,
Contextual Support Government

Best Management Practices - National Association of State Foresters

View Source
Preview of Canadian Water Quality Guidelines for the Protection of Aquatic Life - Total Particulate Matter - CCME, accessed August 10, 2025
Canadian Water Quality Guidelines for the Protection of Aquatic Life - Total Particulate Matter - CCME, accessed August 10, 2025
Contextual Support Journal

Canadian Water Quality Guidelines for the Protection of Aquatic Life - Total Particulate Matter - CCME

View Source
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

Turbidity | Australia state of the environment 2021

View Source
Preview of Criteria and Indicators for Sustainable Forest Management in Victoria
Criteria and Indicators for Sustainable Forest Management in Victoria
Contextual Support Journal

Criteria and Indicators for Sustainable Forest Management in Victoria

View Source
Preview of Ecosystems | Australia state of the environment 2021, accessed August 10, 2025
Ecosystems | Australia state of the environment 2021, accessed August 10, 2025
Contextual Support Journal

Natural Temperate Grassland of the South Eastern Highlands: a nationally protected ecological community - DCCEEW

View Source
Preview of Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 5, 2025,
Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 5, 2025,
Contextual Support GreyLiterature

(PDF) Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 4, 2025,

View Source
Preview of Improved forest management - CSIRO, accessed July 12, 2025,
Improved forest management - CSIRO, accessed July 12, 2025,
Contextual Support Government

Ecosystem wicks: Woodland trees enhance water infiltration in a fragmented agricultural landscape in eastern Australia, accessed May 15, 2025,

View Source
Preview of Logging Impacts On Streams - Cloudfront.net
Logging Impacts On Streams - Cloudfront.net
Contextual Support Journal

The effects of forest management on water quality - SLU

View Source
Preview of TB966 Compendium of Forestry Best Management Practices for Controlling Nonpoint Source Pollution in North America - NCASI
TB966 Compendium of Forestry Best Management Practices for Controlling Nonpoint Source Pollution in North America - NCASI
Contextual Support Journal

New York State Forestry Best Management Practices for Water Quality Field Guide

View Source
Preview of The effects of forest management on water quality - SLU, accessed July 20, 2025
The effects of forest management on water quality - SLU, accessed July 20, 2025
Contextual Support Journal

SA Arid Lands Landscape Regional Summary 2022 Aquatic Ecosystem Condition Report, accessed July 31, 2025,

View Source
Preview of Victorian Government Department of Sustainability and Environment. (2003). Victoria's Criteria and Indicators for Sustainable Forest Management.
Victorian Government Department of Sustainability and Environment. (2003). Victoria's Criteria and Indicators for Sustainable Forest Management.
Direct Evidence Journal

1.1.5.2 Surface water quality | Bioregional Assessments

View Source
Preview of Water clarity around Australia – satellite and in situ observations 3.1 - IMOS Ocean Report, accessed August 10, 2025
Water clarity around Australia – satellite and in situ observations 3.1 - IMOS Ocean Report, accessed August 10, 2025
Contextual Support Journal

Water clarity around Australia – satellite and in situ observations 3.1 - IMOS Ocean Report

View Source
Preview of Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025
Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025
Direct Evidence Government

(PDF) Impact of mitigated forestry activities on turbidity: assessing ...

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,
Contextual Support Government

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

View Source

Context

  • Region Australia
  • Biome Temperate Grassy Woodlands & Plains
  • Land Use Production Forestry
  • Assessment Not Stated
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 9 Jun 2026

Notes

Values consistently above 25 NTU indicate the system is under stress and may not be protecting aquatic ecosystem health. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TGP-FOR-WTU family.

3.3 NTU Moderate
Production Forestry · Not Stated
Point Active v1
— NTU High
Production Forestry · Not Stated
OptimalRange Active v1