Water Electrical Conductivity (EC)

AUS-TMS-URB-WEC General Moderate confidence

Benchmark Value

200 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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The objective states that for the protection of aquatic ecosystems, Electrical Conductivity should be maintained at less than 200 µS/cm.

Metric Definition:

Electrical Conductivity (EC) is a measure of water's ability to pass an electrical current, related to the concentration of dissolved ionic substances (salts).

Benchmark Definition:

This benchmark represents the upper limit of Electrical Conductivity in freshwater rivers and streams in the Darwin Harbour region to protect aquatic ecosystems within the tropical monsoonal savanna biome under urban and developed land use.

Justification:

Derived using the ANZECC/ANZG referential methodology, based on the 80th percentile of data from local, minimally disturbed reference sites, intended to protect high ecological value systems from development impacts.

Sources (1)

Water Quality Objectives for the Darwin Harbour Region - Background Document - Department of Lands, Planning and Environment, accessed July 16, 2025, Journal

Water Quality Objectives for the Darwin Harbour Region - Background Document - Department of Lands, Planning and Environment

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,

Direct Evidence GreyLiterature

(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source

Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,

Direct Evidence Government

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Urban & Developed Use
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Superseded
Version 1
Effective From 5 Jun 2026
Effective To 5 Jun 2026

Notes

This value represents the upper limit of natural variability in healthy streams in the tropical monsoonal savanna biome and serves as the performance target for sustainable urban development. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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