Water Turbidity

AUS-TSW-AQU-WTU General Moderate confidence

Benchmark Value

2 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 15 benchmarks together — the OptimalRange form drives the primary score, while 14 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard Point Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

a sustained turbidity of <2 NTU can be considered a lower critical threshold, below which the system may lack the desired natural productivity.

Metric Definition:

Water Turbidity measured in Nephelometric Turbidity Units (NTU).

Benchmark Definition:

Lower Critical Threshold below which the system may be sterile and unproductive.

Justification:

Based on the lower bound of the ANZECC guidelines for healthy upland rivers and lakes.

Sources (1)

National Guidelines for Water Quality | Department of Natural ..., accessed July 12, 2025, Journal

National Guidelines for Water Quality | Department of Natural ..., accessed July 12, 2025,

View Source

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Aquaculture
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 2
Effective From 1 Jun 2026

Notes

Extremely clear water (e.g., approaching 0 NTU) is not necessarily optimal as it may indicate a sterile, unproductive environment lacking phytoplankton and zooplankton. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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