Water Electrical Conductivity (EC)

AUS-TMS-URB-WEC General High confidence

Benchmark Value

1500 µS/cm

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

A clear upper detrimental threshold is identified at approximately 1500 µS/cm, a level at which widespread, significant adverse impacts on Australian freshwater biota are documented.

Metric Definition:

Electrical Conductivity level at which significant ecological harm occurs due to salinization stress.

Benchmark Definition:

This benchmark marks the upper detrimental threshold of Electrical Conductivity indicating the onset of salinization stress causing significant ecological harm in freshwater ecosystems.

Justification:

Supported by multiple studies documenting reduced biodiversity, growth, and survival of freshwater biota above this EC level.

Sources (1)

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

(PDF) 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.

Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Direct Evidence Government

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

View Source

Preview of Water Quality Objectives for the Darwin Harbour Region - Background Document - Department of Lands, Planning and Environment, accessed July 16, 2025,

Water Quality Objectives for the Darwin Harbour Region - Background Document - Department of Lands, Planning and Environment, accessed July 16, 2025,

Direct Evidence Journal

Water Quality Objectives for the Darwin Harbour Region - Background Document - Department of Lands, Planning and Environment

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Urban & Developed Use
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 2
Effective From 5 Jun 2026

Notes

Waterways exceeding this level are considered significantly degraded with severe ecological impacts. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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