Water Turbidity

AUS-TSW-FOR-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. 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 MinimumOnly Guard MaximumOnly Guard Point Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard UpperThreshold Guard

Evidence & Context

Based on the most robust empirical evidence available, the pre-harvest mean turbidity was 3.3 NTU.9 To account for minor natural variability across different catchments within the biome, a benchmark value of < 5 NTU is established.

Metric Definition:

Water turbidity measured as Nephelometric Turbidity Units (NTU), an optical measure of water clarity quantifying light scattering by suspended particulate matter.

Benchmark Definition:

This benchmark represents the target maximum water turbidity level in Nephelometric Turbidity Units (NTU) for temperate semi-arid woodland catchments under best-practice production forestry management, prior to harvesting disturbance or during recovery.

Justification:

The benchmark is strongly anchored to high-quality, empirical data from a scientifically rigorous, peer-reviewed Australian study that directly measured turbidity under best-practice land-use conditions. The interpretation is framed within nationally accepted guidelines.

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Impact of mitigated forestry activities on turbidity: assessing ..., accessed July 12, 2025,

(PDF) Impact of mitigated forestry activities on turbidity: assessing ..., accessed July 12, 2025,

Direct Evidence

(PDF) Impact of mitigated forestry activities on turbidity: assessing ..., accessed July 12, 2025,

Preview of 1.1.5.2 Surface water quality - Bioregional Assessments |, accessed August 5, 2025,

1.1.5.2 Surface water quality - Bioregional Assessments |, accessed August 5, 2025,

Contextual Support Government

1.1.5.2 Surface water quality - Bioregional Assessments |, accessed July 12, 2025,

Preview of Australia's forests – overview - DAFF, accessed August 5, 2025,

Australia's forests – overview - DAFF, accessed August 5, 2025,

Contextual Support

Boland, D. J., & Dunn, A. T. (1985). Eucalyptus delegatensis: Its ecology and management. Forestry Commission of NSW.

Preview of Australia's State of the Forests Report, accessed August 12, 2025

Australia's State of the Forests Report, accessed August 12, 2025

Contextual Support Journal

Criteria and Indicators for Sustainable Forest Management in Victoria, accessed March 28, 2026,

Preview of Australia's Sustainable Forest Management - DAFF, accessed July 12, 2025,

Australia's Sustainable Forest Management - DAFF, accessed July 12, 2025,

Contextual Support

Sustainable forest management: the Australian context - DAFF, accessed July 12, 2025,

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 Regulatory Framework Government

Best Management Practices - National Association of State Foresters, accessed August 10, 2025

Preview of Deriving guideline values using reference-site data - Water Quality Australia, accessed August 12, 2025

Deriving guideline values using reference-site data - Water Quality Australia, accessed August 12, 2025

Contextual Support Government

Water Quality Guidelines Home - Water Quality Australia

Preview of Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin, accessed July 12, 2025,

Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin, accessed July 12, 2025,

Contextual Support Journal

Dissolved Oxygen (DO) Turbidity - Interstate Commission on the Potomac River Basin

Preview of How Sustainable Forestry Works - Science | HowStuffWorks, accessed July 12, 2025,

How Sustainable Forestry Works - Science | HowStuffWorks, accessed July 12, 2025,

Contextual Support GreyLiterature

How Sustainable Forestry Works - Science | HowStuffWorks, accessed July 12, 2025,

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, accessed August 10, 2025

Preview of National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

Contextual Support Direct Evidence

Australian and New Zealand Guidelines for Fresh and Marine Water ...

Preview of NVIS Fact sheet MVG 13 – Acacia open woodlands - DCCEEW, accessed July 13, 2025,

NVIS Fact sheet MVG 13 – Acacia open woodlands - DCCEEW, accessed July 13, 2025,

Contextual Support Journal

NVIS Fact sheet MVG 13 Acacia open woodlands - DCCEEW, accessed July 10, 2025,

Preview of Protecting waterways - Forestry Corporation, accessed July 12, 2025,

Protecting waterways - Forestry Corporation, accessed July 12, 2025,

Contextual Support Government

Protecting waterways - Forestry Corporation, accessed July 12, 2025,

Preview of The Turbidity Effect on Aquatic Life - Number Analytics, accessed July 12, 2025,

The Turbidity Effect on Aquatic Life - Number Analytics, accessed July 12, 2025,

Contextual Support GreyLiterature

The Turbidity Effect on Aquatic Life - Number Analytics, accessed July 31, 2025,

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

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

Contextual Support Government

Australian Drinking Water Guidelines

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 and Water | U.S. Geological Survey - USGS.gov, accessed August 12, 2025,

Turbidity and Water | U.S. Geological Survey - USGS.gov, accessed August 12, 2025,

Contextual Support

Turbidity and Water | U.S. Geological Survey - USGS.gov, accessed July 31, 2025,

Preview of Turbidity, accessed August 3, 2025,

Turbidity, accessed August 3, 2025,

Contextual Support Journal

Turbidity, accessed July 31, 2025,

Preview of Water Quality and Forestry Best Management Practices, accessed July 12, 2025,

Water Quality and Forestry Best Management Practices, accessed July 12, 2025,

Contextual Support Government

Water Quality and Forestry Best Management Practices, accessed July 12, 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 Woodlands of Australia - A biography of the Australian continent, accessed July 12, 2025,

Woodlands of Australia - A biography of the Australian continent, accessed July 12, 2025,

Contextual Support GreyLiterature

Semi-arid woodlands (shrubby sub-formation) | NSW Environment, Energy and Science, accessed July 8, 2025, )

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Superseded
Version 1
Effective From 13 Mar 2026
Effective To 13 Mar 2026

Notes

The benchmark value represents the mean turbidity in a healthy, well-vegetated catchment within a production forest estate prior to harvesting. The functional range includes no detrimental lower threshold, an optimal range < 10 NTU, and an upper detrimental threshold > 25 NTU.

Related Benchmarks

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