Water Electrical Conductivity (EC)

AUS-TSR-LVG-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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

A seminal review of salt sensitivity in Australian freshwater biota concluded that direct adverse biological effects are likely to occur as salinity approaches 1,500 μS/cm.

Metric Definition:

Electrical Conductivity (EC) threshold for significant aquatic ecosystem degradation

Benchmark Definition:

This benchmark defines the electrical conductivity threshold above which widespread adverse effects and significant shifts in aquatic community composition are expected in tropical and subtropical rainforest freshwater ecosystems under livestock grazing and pasture land use.

Justification:

This threshold is based on a seminal review of salt sensitivity in Australian freshwater biota indicating significant ecosystem changes at this level.

Sources (1)

Preview of Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - CSIRO Research Publications Repository
Effect of reduced grazing pressure on sediment and nutrient yields in savanna rangeland streams draining to the Great Barrier Reef - CSIRO Research Publications Repository Journal

Hillslope gully erosion in savanna rangelands tributary to the Great ..., accessed July 19, 2025,

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) A review of the salt sensitivity of the Australian freshwater biota, accessed August 11, 2025,
(PDF) A review of the salt sensitivity of the Australian freshwater biota, accessed August 11, 2025,
Direct Evidence Journal

Salinity Tolerances of Freshwater Macroinvertebrates

View Source
Preview of Accessory Publication Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia
Accessory Publication Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia
Direct Evidence Journal

Pine Creek, near Dutton 2010 Aquatic Ecosystem Condition Report - EPA SA

View Source
Preview of Tully River, Murray River and Hinchinbrook Island Basins Environmental Values and Water Quality Objectives
Tully River, Murray River and Hinchinbrook Island Basins Environmental Values and Water Quality Objectives
Direct Evidence Journal

Environmental Protection (Water and Wetland Biodiversity) Policy 2019: Tully, Murray and Hinchinbrook Island River Basins Environmental Values and Water Quality Objectives

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 20 Mar 2026

Notes

A system consistently at or above this level is considered significantly degraded.

Related Benchmarks

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

— μS/cm Moderate
Livestock Grazing & Pasture · Pristine Reference
OptimalRange Active v1