Water Electrical Conductivity (EC)

AUS-TSR-URB-WEC General Moderate confidence

Benchmark Value

No specific value — see range

Range: 20 to 110.9 µS/cm

Optimal Range: 20 to 110.9

Direction: Higher 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

These streams, representing high-health reference sites, were found to have an electrical conductivity range of 20.0 to 110.9 µS/cm.

Metric Definition:

Electrical Conductivity (EC) is a fundamental measure of water quality, quantifying the ability of water to conduct an electrical current.

Benchmark Definition:

This benchmark represents the natural electrical conductivity range of high-health freshwater streams in the Tropical & Subtropical Rainforests biome under urban and developed land use in Australia, indicating ion-poor conditions.

Justification:

This range is exceptionally low, confirming that the natural state of these freshwater systems is ion-poor.

Sources (1)

Preview of Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025,

Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025, Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ)

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed August 2, 2025,

Direct Evidence

Requirements for graziers | Environment, land and water ..., accessed July 19, 2025,

View Source

Water-Quality-Salinity-Standards.pdf, accessed August 11, 2025,

Direct Evidence Journal

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

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Urban & Developed Use
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 20 Mar 2026

Notes

This empirically observed range of 20-111 µS/cm is therefore considered the Optimal Range for supporting the full suite of native aquatic biodiversity and ecological functions in this biome.

Related Benchmarks

Other benchmarks in the AUS-TSR-URB-WEC family.