Water Electrical Conductivity (EC)

AUS-AIF-CON-WEC General High confidence

Benchmark Value

800 μS/cm

Direction: Higher 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

Therefore, a benchmark representing the best available condition should reflect the state that supports high biodiversity and is characteristic of the system during its productive phases (baseflow or early recession). A value of < 800 ³S/cm serves as a robust and defensible benchmark.

Metric Definition:

Water Electrical Conductivity (EC)

Benchmark Definition:

This benchmark represents the upper limit of water electrical conductivity that supports high biodiversity and ecosystem health in Australia's arid inland floodplains during productive flow phases.

Justification:

It is consistent with the qualitative assessment of the premier reference site, aligns with a national management definition of "low salinity," and is protective of the biological communities that underpin ecosystem health.

Sources (3)

Preview of Salinity - Murray–Darling Basin Authority, accessed August 11, 2025,

Salinity - Murray–Darling Basin Authority, accessed August 11, 2025, 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

View Source

Preview of Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern MurrayDarling Basin (Victoria, Australia) - Canadian Science Publishing

Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern MurrayDarling Basin (Victoria, Australia) - Canadian Science Publishing Journal

Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern MurrayDarling Basin (Victoria, Australia) - Canadian Science Publishing

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Preview of Water and sediment quality in the Diamantina-Georgina River catchment, Lake Eyre Basin

Water and sediment quality in the Diamantina-Georgina River catchment, Lake Eyre Basin Journal

Water quality in the Georgina-Diamantina River catchment

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Water quality in two Australian dryland rivers: spatial and temporal variability and the role of flow - ResearchGate, accessed July 30, 2025,

(PDF) Water quality in two Australian dryland rivers: spatial and temporal variability and the role of flow - ResearchGate, accessed July 30, 2025,

Direct Evidence

(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

The benchmark represents the upper limit of the optimal range for high ecological health in Australia's arid inland river systems. It is based on a synthesis of evidence: 1) The Georgina-Diamantina catchment in the Lake Eyre Basin, a minimally disturbed system, is described as having "low salinity". 2) The MDBA defines "low salinity" as < 800 ³S/cm. 3) Biological studies show macroinvertebrate richness declines above 300-500 ³S/cm, making < 800 ³S/cm a protective value.

Related Benchmarks

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