Water Turbidity

AUS-TDG-CON-WTU General High confidence

Benchmark Value

10 NTU

Thresholds: Lower: —, Upper: 10

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 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary UpperThreshold Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

The 2021 CHIP report highlighted headwater reaches of the Badja River (BAD1), Numeralla River (NUM2), and Hospital Creek in Namadgi National Park (HOS1) as having "Excellent" water quality, implying turbidity was consistently ²6410 NTU.

Metric Definition:

Water turbidity measured in Nephelometric Turbidity Units (NTU) representing the upper limit for excellent ecological status in Conservation / Protected Natural Areas within Australian Temperate Dry Woodlands & Native Grasslands.

Benchmark Definition:

This benchmark represents the maximum turbidity level for excellent water quality in protected natural areas of Australian temperate dry woodlands and native grasslands, indicating pristine reference conditions.

Justification:

Directly aligns with "Excellent" water quality criteria in relevant regional monitoring programs within conservation areas of the target biome.

Sources (1)

Preview of Upper Murrumbidgee Waterwatch Catchment Health Indicator Program (CHIP) Reports (e.g., 2021, 2023) and associated methodology defining "Excellent" water quality thresholds.

Upper Murrumbidgee Waterwatch Catchment Health Indicator Program (CHIP) Reports (e.g., 2021, 2023) and associated methodology defining "Excellent" water quality thresholds. Journal

Upper Murrumbidgee Waterwatch Catchment Health Indicator Program - Upper Murrumbidgee Waterwatch

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Default guideline values - Water Quality Australia, accessed August 12, 2025

Direct Evidence Government

ANZECC (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

View Source

Feral horses (Equus caballus) increase suspended sediment in subalpine streams

Contextual Support Journal

Feral horses (Equus caballus) increase suspended sediment in subalpine streams

View Source

Context

Region Australia
Biome Temperate Dry Woodlands & Native Grasslands
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

Values consistently above 10 NTU are sub-optimal for maintaining the best available condition.

Related Benchmarks

Other benchmarks in the AUS-TDG-CON-WTU family.