Water Electrical Conductivity (EC)

AUS-TSW-URB-WEC General Moderate confidence

Benchmark Value

No specific value — see range
Range: 0 to 280 µS/cm
Thresholds: Lower: —, Upper: 280
Optimal Range: 0 to 280
Direction: Lower is desirable ↓
Form: OptimalRange

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 14 benchmarks together — the OptimalRange form drives the primary score, while 13 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The benchmark represents the best available condition for high ecological health in urban streams within Australia's temperate semi-arid biome. It is derived from an ecological threshold study in South Australia's Mount Lofty Ranges, a representative region. This value is chosen to protect the most sensitive aquatic biota (diatoms), which exhibit significant community stress above this level.

Metric Definition:

Water Electrical Conductivity (EC) is a physical property of water that measures its ability to pass an electrical current, directly proportional to the concentration of dissolved, electrically charged ions in the water.

Benchmark Definition:

This benchmark defines the optimal range of water electrical conductivity in urban streams of Australia's temperate semi-arid shrublands and open woodlands, protecting sensitive aquatic life by limiting salinity to below 280 µS/cm.

Justification:

This benchmark is based on an ecological threshold study linking EC levels to biological stress in sensitive diatom communities, representing a scientifically defensible protective target.

Sources (2)

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Ambient Water Quality Monitoring of South Australia's Rivers and Streams Journal

Ambient Water Quality Monitoring of South Australia's Rivers and Streams

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Analysis of 14 years of macroinvertebrates data from the Mediterranean catchments of the Torrens and Onkaparinga Rivers, South-Australia GreyLiterature

Analysis of 14 years of macroinvertebrates data from the Mediterranean catchments of the Torrens and Onkaparinga Rivers, South-Australia

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Supporting Sources (28)

Additional references from the underlying research that informed this benchmark.

Preview of 1.1.7.1 Ecological systems | Bioregional Assessments, accessed July 13, 2025,
1.1.7.1 Ecological systems | Bioregional Assessments, accessed July 13, 2025,
Contextual Support Government

NVIS Fact sheet MVG 19 – Tussock grasslands, accessed July 13, 2025

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Assessing Water Quality - Secondary Education Years 9 to 12 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,
Contextual Support Journal

Assessing water quality - ACT Waterwatch

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Preview of Characterising the relationship between water quality and water quantity, accessed August 5, 2025
Characterising the relationship between water quality and water quantity, accessed August 5, 2025
Contextual Support Journal

Report Card 2022-23 - EPA Victoria

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Conductivity (Electrical Conductance) and Water | U.S. Geological Survey - USGS.gov, accessed August 4, 2025,
Contextual Support

Conductivity (Electrical Conductance) and Water | U.S. Geological Survey - USGS.gov, accessed July 13, 2025

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Preview of Conductivity (electrolytic) - Wikipedia, accessed July 13, 2025
Conductivity (electrolytic) - Wikipedia, accessed July 13, 2025
Contextual Support

Conductivity (electrolytic) - Wikipedia, accessed July 13, 2025

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Preview of East Australian Mediterranean Woodlands & Temperate Savannas ..., accessed July 15, 2025
East Australian Mediterranean Woodlands & Temperate Savannas ..., accessed July 15, 2025
Contextual Support

Temperate Grasslands - Greening Australia

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Preview of Effectiveness of Water-Sensitive Urban Design Techniques on Stormwater Quantity Management at a Residential Allotment Scale - MDPI, accessed August 2, 2025,
Effectiveness of Water-Sensitive Urban Design Techniques on Stormwater Quantity Management at a Residential Allotment Scale - MDPI, accessed August 2, 2025,
Contextual Support

Targets for Urban Stormwater Management in Australia - MDPI, accessed July 13, 2025

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Preview of EPA Aquatic Ecosystem Condition Reports - Home - WaterConnect, accessed July 13, 2025
EPA Aquatic Ecosystem Condition Reports - Home - WaterConnect, accessed July 13, 2025
Contextual Support Government

EPA Aquatic Ecosystem Condition Reports - Home - WaterConnect, accessed July 13, 2025

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Preview of Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,
Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,
Contextual Support Journal

Guidance document for assessing and managing water quality in temporary waters, accessed July 10, 2025,

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Preview of Interim Biogeographic Regionalisation for Australia - Wikipedia, accessed July 13, 2025,
Interim Biogeographic Regionalisation for Australia - Wikipedia, accessed July 13, 2025,
Contextual Support GreyLiterature

Category:IBRA regions - Wikipedia, accessed August 1, 2025

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Preview of New sensitivity grades for Australian river macroinvertebrates - Murray-Darling Freshwater Research Centre
New sensitivity grades for Australian river macroinvertebrates - Murray-Darling Freshwater Research Centre
Direct Evidence Journal

AECR - 2016 panel assessment of creeks and rivers from the Adelaide and MLR NRM region - EPA SA, accessed July 13, 2025

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Preview of NVIS Fact sheet MVG 17 – Other shrublands - DCCEEW, accessed July 15, 2025
NVIS Fact sheet MVG 17 – Other shrublands - DCCEEW, accessed July 15, 2025
Contextual Support Journal

NVIS Fact sheet MVG 17 – Other shrublands - DCCEEW, accessed July 13, 2025

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Preview of NVIS Fact sheet MVG 19 6 Tussock grasslands, accessed July 16, 2025,
NVIS Fact sheet MVG 19 6 Tussock grasslands, accessed July 16, 2025,
Contextual Support Journal

Understanding soil pH, accessed August 28, 2025,

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Preview of Salinity - Murray�darling Basin Authority
Salinity - Murray�darling Basin Authority
Contextual Support GreyLiterature

Why test for electrical conductivity, acidity and alkalinity? - The Australian Museum, accessed July 13, 2025

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Preview of Salinity in Western Australia : a situation statement - DPIRD's Digital library, accessed July 10, 2025,
Salinity in Western Australia : a situation statement - DPIRD's Digital library, accessed July 10, 2025,
Contextual Support

Characterising the relationship between water quality and water quantity, accessed July 13, 2025

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Preview of Salinity is not necessarily bad for biodiversity: case studies of invertebrates from South Australian streams and River Murray wetlands - EPA SA, accessed July 13, 2025
Salinity is not necessarily bad for biodiversity: case studies of invertebrates from South Australian streams and River Murray wetlands - EPA SA, accessed July 13, 2025
Contextual Support Journal

Temporal Patterns and Environmental Correlates of Macroinvertebrate Communities in Temporary Streams | PLOS One, accessed July 13, 2025

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Preview of Salinity is not necessarily bad for biodiversity: case studies of invertebrates from South Australian streams and River Murray wetlands, accessed May 15, 2025,
Salinity is not necessarily bad for biodiversity: case studies of invertebrates from South Australian streams and River Murray wetlands, accessed May 15, 2025,
Contextual Support Journal

Indicators: Conductivity | US EPA, accessed July 13, 2025

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Semi-arid woodlands (shrubby sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )
Contextual Support Government

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Preview of Stream-salinity-status-and-trends-in-south-west-WA.pdf, accessed July 13, 2025
Stream-salinity-status-and-trends-in-south-west-WA.pdf, accessed July 13, 2025
Contextual Support GreyLiterature

Salinity and Land Use Impacts Stream salinity status and trends in south-west Western Australia - ResearchGate, accessed July 13, 2025

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Preview of Targets for Urban Stormwater Management in Australia - MDPI, accessed July 21, 2025
Targets for Urban Stormwater Management in Australia - MDPI, accessed July 21, 2025
Direct Evidence Journal

J. Tibby's research works | The University of Adelaide and other places, accessed July 13, 2025

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Preview of The Relationship between Electrical Conductivity and Selected Macroinvertebrate Communities in Four River Systems of South-West Victoria, Australia - ResearchGate
The Relationship between Electrical Conductivity and Selected Macroinvertebrate Communities in Four River Systems of South-West Victoria, Australia - ResearchGate
Direct Evidence Journal

The Relationship between Electrical Conductivity and Selected Macroinvertebrate Communities in Four River Systems of South-West Victoria, Australia - ResearchGate

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The urban stream syndrome: current knowledge and the search for a cure - UCI Water-PIRE, accessed July 13, 2025
Contextual Support

The urban stream syndrome: current knowledge and the search for a cure - UCI Water-PIRE, accessed July 13, 2025

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Total dissolved solids | Australian Drinking Water Guidelines - NHMRC, accessed July 27, 2025,
Contextual Support Government

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Preview of Water Sensitive Urban Design Guidelines - Clearwater, accessed July 13, 2025
Water Sensitive Urban Design Guidelines - Clearwater, accessed July 13, 2025
Contextual Support GreyLiterature

(PDF) AUSTRALIA'S WATER SENSITIVE URBAN DESIGN - ResearchGate, accessed July 13, 2025

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Preview of Water Sensitive Urban Design Guidelines - Melbourne Water, accessed July 13, 2025
Water Sensitive Urban Design Guidelines - Melbourne Water, accessed July 13, 2025
Contextual Support

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Preview of Water Sensitive Urban Design Guidelines - Melbourne Water, accessed July 21, 2025,
Water Sensitive Urban Design Guidelines - Melbourne Water, accessed July 21, 2025,
Contextual Support Journal

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Preview of Water Sensitivity Urban Design (WSUD) Guideline 2018 - City of Coffs Harbour, accessed July 13, 2025
Water Sensitivity Urban Design (WSUD) Guideline 2018 - City of Coffs Harbour, accessed July 13, 2025
Contextual Support Journal

Water Sensitivity Urban Design (WSUD) Guideline 2018 - City of Coffs Harbour, accessed July 13, 2025

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Preview of Water-Quality-Salinity-Standards.pdf, accessed August 11, 2025,
Water-Quality-Salinity-Standards.pdf, accessed August 11, 2025,
Contextual Support Journal

What Is The Typical Water Conductivity Range? - Atlas Scientific, accessed July 13, 2025

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Context

  • Region Australia
  • Biome Temperate Semi-Arid Shrublands & Open Woodlands
  • Land Use Urban & Developed Use
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 22 Mar 2026

Notes

The benchmark is more protective than the median EC of 'good' quality reference streams (e.g., First Creek median EC of 333 µS/cm). There is no evidence for a lower critical threshold; the main management challenge is mitigating elevated EC due to urbanization.