Water Electrical Conductivity (EC)

AUS-TSW-URB-WEC General Moderate confidence

Benchmark Value

280 µS/cm
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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The most precise evidence for this threshold comes from the analysis of diatom communities in South Australian streams, which identified a significant decline in the abundance of sensitive species at an EC of approximately 280 µS/cm.

Metric Definition:

Water Electrical Conductivity (EC) measures the ability of water to conduct an electrical current, directly proportional to the concentration of dissolved ions, serving as a proxy for salinity and total dissolved solids.

Benchmark Definition:

This benchmark represents the upper limit of water electrical conductivity in urban streams within Australia's temperate semi-arid biome to protect sensitive aquatic species and maintain high ecological health.

Justification:

This benchmark is based on a documented biological tipping point where sensitive diatom species show significant community stress, representing the highest achievable state of environmental health in the biome.

Sources (1)

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

View Source

Supporting Sources (29)

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

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

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Preview of Assessing Water Quality - Secondary Education Years 9 to 12 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,
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

Turbidity | Australia state of the environment 2021

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

5.9 Conductivity | Monitoring & Assessment | US EPA, accessed August 4, 2025

View Source
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

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

Plants of the mallee shrublands - Australian National Botanic Gardens, accessed July 13, 2025

View Source
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

Effectiveness of Water-Sensitive Urban Design Techniques on Stormwater Quantity Management at a Residential Allotment Scale - MDPI, accessed August 11, 2025

View Source
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

View Source
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,

View Source
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

View Source
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

View Source
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 19 – Tussock grasslands, accessed July 13, 2025

View Source
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

View Source
Preview of Salinity - Murray�darling Basin Authority
Salinity - Murray�darling Basin Authority
Contextual Support Journal

Salinity - Murray–Darling Basin Authority

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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

finalrepport - MLA, accessed July 28, 2025

View Source
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

View Source
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

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

Semi-arid woodlands (grassy sub-formation) | NSW Environment, Energy and Science

View Source
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

View Source
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

Targets for Urban Stormwater Management in Australia - MDPI, accessed July 21, 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 GreyLiterature

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

View Source
Preview of The urban stream syndrome: current knowledge and the search for a cure - UCI Water-PIRE, accessed July 13, 2025
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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Preview of Total dissolved solids | Australian Drinking Water Guidelines - NHMRC, accessed July 27, 2025,
Total dissolved solids | Australian Drinking Water Guidelines - NHMRC, accessed July 27, 2025,
Contextual Support Government

Australian and New Zealand Guidelines for Fresh and Marine Water Quality

View Source
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

Issues affecting water quality, accessed July 13, 2025

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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

Section 13 – Water Sensitive Urban Design (WSUD) Guidelines - City of Gold Coast, accessed July 13, 2025

View Source
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

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

(PDF) Effects of increasing salinity on freshwater ecosystems in ..., accessed July 21, 2025

View Source

Context

  • Region Australia
  • Biome Temperate Semi-Arid Shrublands & Open Woodlands
  • Land Use Urban & Developed Use
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 8 Jun 2026

Notes

The benchmark protects the most sensitive aquatic biota (diatoms) and is more protective than the median EC of 'good' quality reference streams. There is no evidence for a lower critical EC threshold; the management challenge is exclusively mitigating elevated EC.