Water Electrical Conductivity (EC)

AUS-TSR-AGR-WEC General Moderate confidence

Benchmark Value

106 μS/cm

Range: 20 to 110 μS/cm

Optimal Range: 20 to 110

Direction: Higher is desirable ↑

Form: Point

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

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard Point Guard Point Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard UpperThreshold Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MinimumOnly Guard Point Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

The reference value of 106 ³S/cm is the 80th percentile of baseline data from reference sites used to set the official Water Quality Objectives for the Johnstone River Basin, a representative Wet Tropics catchment.

Metric Definition:

Water Electrical Conductivity (EC) as a measure of the water's ability to conduct electricity, directly proportional to the concentration of total dissolved ions.

Benchmark Definition:

This benchmark represents the reference water electrical conductivity level for the Johnstone River Basin in the Tropical & Subtropical Rainforests biome under Agricultural Crop Production land use, indicating a scientifically defensible proxy for best available water quality conditions.

Justification:

This value of 106 μS/cm serves as an excellent, scientifically defensible proxy for the 'best available condition' benchmark. It is locally derived, scientifically robust, aligns with the natural baseline, and is a realistic target for sustainable agriculture.

Sources (1)

Johnstone River Basin Environmental Values and Water Quality ... Journal

Johnstone River Basin Environmental Values and Water Quality ...

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate, accessed August 11, 2025,

Contextual Support Journal

Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source

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,

Direct Evidence Journal

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

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type TargetCondition

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

The benchmark value of 106 μS/cm is derived from the 80th percentile of baseline data from local reference sites, within the natural background range of 20-110.9 μS/cm observed in pristine forested streams. The optimal range for ecosystem health is 20-110 μS/cm. Values above 110 μS/cm indicate departure from high-health conditions, with higher thresholds at 350 μS/cm and 1500 μS/cm indicating increasing levels of disturbance and degradation.

Related Benchmarks

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