Water Turbidity

AUS-AKW-URB-WTU General Low confidence

Benchmark Value

No specific value — see range
Range: 0 to 5 NTU
Thresholds: Lower: —, Upper: 50
Optimal Range: 0 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.

Evidence & Context

The optimal range is considered < 5 NTU, reflecting the clear water conditions of natural refuge pools between rainfall events.

Metric Definition:

Water turbidity as a measure of water clarity, quantifying the degree to which light is scattered by suspended particles such as silt, clay, organic matter, and microorganisms.

Benchmark Definition:

This benchmark defines the optimal water turbidity range indicating high water quality and ecological condition in urban and developed areas of the Arid Karstic Woodlands & Shrublands biome.

Justification:

The optimal range aligns with the lower end of ANZECC guidelines for high conservation value ecosystems and aesthetic drinking water standards.

Sources (1)

Preview of Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025
Water Quality Objectives - Border Rivers - NSW Government, accessed August 12, 2025 Government

(PDF) Impact of mitigated forestry activities on turbidity: assessing ..., accessed August 10, 2025

View Source

Context

  • Region Australia
  • Biome Arid Karstic Woodlands & Shrublands
  • Land Use Urban & Developed Use
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 19 Mar 2026

Notes

Lower critical threshold is not applicable; lower turbidity consistently indicates better ecological health. An upper detrimental threshold is identified at 50 NTU; sustained turbidity above this level indicates a degraded state and potential for significant ecological harm.

Related Benchmarks

Other benchmarks in the AUS-AKW-URB-WTU family.