Water Electrical Conductivity (EC)

AUS-TSR-CON-WEC General Moderate confidence

Benchmark Value

1500 µS/cm

Thresholds: Lower: —, Upper: 1500

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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Direct, adverse biological effects become likely across a range of biota once salinity exceeds 1000 mg/L, which corresponds to an electrical conductivity of approximately 1500 µS/cm.

Metric Definition:

Electrical conductivity level at which salinity causes direct and widespread harm to freshwater ecosystems.

Benchmark Definition:

This benchmark represents the critical upper threshold of electrical conductivity beyond which severe ecological degradation and biological harm occur in freshwater ecosystems.

Justification:

Established by seminal reviews and subsequent work indicating biological harm at this level.

Sources (2)

(PDF) Effects of increasing salinity on freshwater ecosystems in ... Journal

(PDF) Effects of increasing salinity on freshwater ecosystems in ...

View Source

Ecology of streams in a biogeographic isolate—the Queensland Wet ... Journal

Ecology of streams in a biogeographic isolate—the Queensland Wet ...

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Barron River Basin Environmental Values and Water Quality ..., accessed July 21, 2025,

Direct Evidence Journal

Effects of total dissolved solids on growth and mortality predict ...

View Source

Preview of Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025,

Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025,

Direct Evidence Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ)

View Source

Environmental Protection (Water and Wetland Biodiversity) Policy 2019 | Environment, accessed July 27, 2025,

Regulatory Framework Government

Environmental Protection (Water and Wetland Biodiversity) Policy 2019 | Environment

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 24 Mar 2026

Notes

Levels approaching this value signify severe degradation and major adverse biological effects, including loss of species diversity and disruption of critical life-cycle processes.

Related Benchmarks

Other benchmarks in the AUS-TSR-CON-WEC family.