Water Electrical Conductivity (EC)

AUS-TGP-AQU-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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The scientific literature consistently suggests that once salinity exceeds an EC of approximately 1500µS/cm (equivalent to ~1000 mg/L TDS), adverse effects are observed across a wide range of aquatic biota.

Metric Definition:

Electrical Conductivity (EC) level indicating widespread ecological damage and highly disturbed system status.

Benchmark Definition:

This benchmark indicates the threshold at which water quality causes widespread ecological damage and a highly disturbed system status in Australia's Temperate Grassy Woodlands & Plains.

Justification:

Based on consistent scientific literature indicating adverse effects 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 (5)

Additional references from the underlying research that informed this benchmark.

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,

Direct Evidence Journal

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

View Source

Murray-Darling Basin - Monthly Water Update - AWRA - Bureau of Meteorology

Contextual Support Journal

Murray-Darling Basin - Monthly Water Update - AWRA - Bureau of Meteorology

View Source

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

Contextual Support Government

Salinity | Murray–Darling Basin Authority

View Source

Salinity - Murray�darling Basin Authority

Contextual Support Journal

Salinity - Murray–Darling Basin Authority

View Source

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

Regulatory Framework Government

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

View Source

Context

Region Australia
Biome Temperate Grassy Woodlands & Plains
Land Use Aquaculture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 2
Effective From 3 Jun 2026

Notes

Waterways consistently above 1500 µS/cm are considered highly disturbed or degraded. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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