Water Electrical Conductivity (EC)

AUS-TMS-AQU-WEC General Moderate confidence

Benchmark Value

30 μS/cm

Thresholds: Lower: 30, Upper: —

Direction: Higher 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 18 benchmarks together — the OptimalRange form drives the primary score, while 17 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

ANZECC (2000) default lower trigger value for upland rivers of 30 μS/cm provides a useful and conservative indicator of a level below which ionoregulatory stress may begin

Metric Definition:

Lower critical threshold of Electrical Conductivity (EC) below which ionoregulatory stress occurs in freshwater fauna

Benchmark Definition:

The lower critical threshold of electrical conductivity indicating ionoregulatory stress in freshwater fish.

Justification:

Based on ANZECC (2000) guidelines as a conservative indicator for ionoregulatory stress.

Sources (1)

Preview of Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000), accessed May 11, 2025,

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000), accessed May 11, 2025, Journal

Northern Territory Government (2020) Darwin Harbour Region Water Quality Objectives, Report Card Section 3.0.

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate, accessed August 11, 2025,

Contextual Support Journal

Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source

A Compendium of Ecological Information on Australia's ... - DCCEEW

Contextual Support Government

A Compendium of Ecological Information on Australia's ... - DCCEEW

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Aquaculture
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 19 Mar 2026

Notes

Values below this threshold may induce physiological stress in freshwater fauna.

Related Benchmarks

Other benchmarks in the AUS-TMS-AQU-WEC family.