Water Turbidity

AUS-TMS-URB-WTU General High confidence

Benchmark Value

No specific value — see range

Range: 0 to 4 NTU

Optimal Range: 0 to 4

Direction: Lower 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 2 benchmarks together — the OptimalRange form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard

Evidence & Context

The optimal range for water turbidity in a well-managed urban waterway within a tropical monsoonal savanna can be defined as 0–4 NTU.

Metric Definition:

Water turbidity concentration in surface waters

Benchmark Definition:

Optimal turbidity range for high ecosystem health in urban tropical monsoonal savanna waterways.

Justification:

Synthesized from evidence of detrimental effects above 5 NTU and lack of lower critical threshold in urban systems.

Sources (2)

Preview of Clarity and colour - WetlandInfo, accessed August 12, 2025,

Clarity and colour - WetlandInfo, accessed August 12, 2025, Government

Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management - PMC - PubMed Central

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Preview of Water Quality Guidelines Level of protection, accessed August 11, 2025,

Water Quality Guidelines Level of protection, accessed August 11, 2025, Government

Water quality objectives for the Darwin Harbour Region

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Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of A review of guideline development for suspended solids and salinity in tropical rivers of Queensland, Australia - ResearchGate, accessed May 11, 2025,

A review of guideline development for suspended solids and salinity in tropical rivers of Queensland, Australia - ResearchGate, accessed May 11, 2025,

Contextual Support Journal

Queensland Water Quality Guidelines (QWQG), accessed July 25, 2025,

View Source

Darwin Harbour water quality report 2020 | Department of Lands ...

Direct Evidence Government

Darwin Harbour water quality report 2020 | Department of Lands ...

View Source

Darwin Harbour water quality report 2020 | Department of Lands, Planning and Environment

Direct Evidence Government

Darwin Harbour water quality report 2021 | Department of Lands ...

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Urban & Developed Use
Assessment Pristine Reference
Season ambient (non-flood) conditions
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 5 Jun 2026

Notes

This range reflects the aspirational goal of achieving the highest possible water clarity, with the benchmark of <4 NTU representing the upper limit of a demonstrated, high-performance state.

Related Benchmarks

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