Water Electrical Conductivity (EC)

AUS-TMS-AQU-WEC General Moderate confidence

Benchmark Value

1500 μS/cm

Thresholds: Lower: —, Upper: 1500

Direction: Higher is desirable ↑

Form: UpperThreshold

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

aquatic biota will be adversely affected as salinity exceeds 1000 mg L−1, which is equivalent to an EC of approximately 1500 μS/cm

Metric Definition:

Upper detrimental threshold of Electrical Conductivity (EC) above which freshwater biota are adversely affected

Benchmark Definition:

The upper detrimental threshold of electrical conductivity indicating ecological harm to freshwater biota.

Justification:

Based on a key review by Hart et al. (1991) and subsequent government assessments.

Sources (1)

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

Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

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

Contextual Support Government

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

View Source

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

Regulatory Framework Journal

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

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

Exceeding this threshold signifies a transition to a degraded, salinized ecosystem state.

Related Benchmarks

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