Water Electrical Conductivity (EC)

AUS-TGP-AQU-WEC General High confidence

Benchmark Value

280 μS/cm
Range: 50 to 280 μS/cm
Thresholds: Lower: —, Upper: 280
Optimal Range: 50 to 280
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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Evidence & Context

The research identifies a distinct threshold of ecological change at an Electrical Conductivity of approximately 280μS/cm.

Metric Definition:

Electrical Conductivity (EC) is a fundamental measure of water quality that quantifies the ability of a solution to conduct an electrical current, measured in microSiemens per centimeter (μS/cm) at 25 0C.

Benchmark Definition:

This benchmark defines the upper limit of electrical conductivity in freshwater streams to maintain high ecological health, marking the onset of stress in sensitive aquatic species in the Temperate Grassy Woodlands & Plains biome under aquaculture land use.

Justification:

This value is based on a robust, peer-reviewed study specific to the target biome's stream types and aligns with the best-practice methodology recommended by national water quality guidelines.

Sources (1)

Preview of Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research, accessed May 15, 2025,
Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research, accessed May 15, 2025, Journal

Diatom0water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research

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Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate, accessed August 11, 2025,
(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
Preview of Salinity - Murray–Darling Basin Authority, accessed August 11, 2025,
Salinity - Murray–Darling Basin Authority, accessed August 11, 2025,
Contextual Support Government

Basin Plan water quality targets; Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG 2018/ANZECC 2000); Australia State of the Environment 2021: Inland water

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Context

  • Region Australia
  • Biome Temperate Grassy Woodlands & Plains
  • Land Use Aquaculture
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 17 Mar 2026

Notes

The optimal range for high ecological health is approximately 50 to less than 280 μS/cm. Levels above 280 μS/cm indicate increasing ecological stress, with further degradation observed at higher EC levels.