Water Electrical Conductivity (EC)

AUS-TMI-AGR-WEC General Moderate confidence

Benchmark Value

930 µS/cm

Direction: Lower is desirable ↓

Form: MinimumOnly

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 Point Guard Point Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard UpperThreshold Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MinimumOnly Guard Point Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

Sensitive macroinvertebrate taxa decline sharply at EC levels above approximately 930 µS/cm.

Metric Definition:

Ecological threshold for macroinvertebrate community degradation based on Electrical Conductivity (EC).

Benchmark Definition:

This benchmark marks the ecological tipping point where aquatic macroinvertebrate communities begin to degrade significantly due to elevated electrical conductivity.

Justification:

Represents a hard ecological ceiling beyond which the aquatic ecosystem is actively degrading.

Sources (1)

Preview of A Compendium of Ecological Information on Australia's Northern Tropical Rivers - Report 5 - Water quality - DCCEEW, accessed August 1, 2025,

A Compendium of Ecological Information on Australia's Northern Tropical Rivers - Report 5 - Water quality - DCCEEW, accessed August 1, 2025, Journal

Threshold Indicator Taxa ANalysis and change points (dots) for the ...

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Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG)

Contextual Support Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG)

View Source

Preview of Proserpine River, Whitsunday Island and O'Connell River Basins Environmental Values and Water Quality Objectives - Queensland Environment Department, accessed August 2, 2025,

Proserpine River, Whitsunday Island and O'Connell River Basins Environmental Values and Water Quality Objectives - Queensland Environment Department, accessed August 2, 2025,

Regulatory Framework Journal

Bioregional Assessment of the Clarence-Moreton bioregion, which includes the Richmond River basin

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VOLUME 1 WATER RESOURCES OF THE TIWI ... - Tiwi Land Council

Contextual Support Government

VOLUME 1 WATER RESOURCES OF THE TIWI ... - Tiwi Land Council

View Source

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

Exceeding this threshold indicates a system no longer in a high-health state.

Related Benchmarks

Other benchmarks in the AUS-TMI-AGR-WEC family.