Water Turbidity

AUS-TDG-CON-WTU General Moderate confidence

Benchmark Value

10 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 11 benchmarks together — the OptimalRange form drives the primary score, while 10 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

An upper threshold for maintaining "excellent" or "best available" ecological condition should not exceed 10 NTU.

Metric Definition:

Water turbidity measured in Nephelometric Turbidity Units (NTU) during baseflow conditions.

Benchmark Definition:

Upper limit for excellent ecological status during baseflow in Temperate Dry Woodlands & Native Grasslands conservation areas.

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

Catchment Health Indicator Program - Upper Murrumbidgee Waterwatch

View Source

Supporting Sources (3)

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

Yellow Box – Red Gum Grassy Woodland, accessed August 12, 2025,

Contextual Support Journal

Indicator W3: Water quality - ACT State of the Environment

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 2
Effective From 10 Jun 2026

Notes

Persistent turbidity values above this threshold indicate sub-optimal conditions and potential ecological stress.

Related Benchmarks

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