Water Electrical Conductivity (EC)

AUS-ASC-CON-WEC General Moderate confidence

Benchmark Value

50 µS/cm

Thresholds: Lower: 5, Upper: —

Direction: Lower is desirable ↓

Form: MinimumOnly

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Chronic exposure to EC values consistently exceeding the natural background range (e.g., >50-100 µS/cm) should be considered a trigger for investigation and concern in high conservation value alpine streams.

Metric Definition:

Lower bound of electrical conductivity above which ecological concern is triggered in Australian alpine aquatic ecosystems.

Benchmark Definition:

Threshold EC value above which chronic exposure indicates ecological concern in alpine streams.

Justification:

Based on direct evidence of ecological impacts at EC levels exceeding natural background in sensitive alpine ecosystems.

Sources (1)

Impacts of road de-icing salts on water quality and macroinvertebrates in streams of the Australian Alps (Shenton et al., 2021).

Impacts of road de-icing salts on water quality and macroinvertebrates in streams of the Australian Alps (Shenton et al., 2021).

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) - V, accessed July 22, 2025

Direct Evidence Journal

1.5.2.1 Surface water - Bioregional Assessments |

View Source

Review of water quality studies in the Australian Alps, accessed August 12, 2025,

Contextual Support Government

Review of water quality studies in the Australian Alps | Australian ...

View Source

Context

Region Australia
Biome Alpine and Subalpine Complex
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 17 Mar 2026

Notes

Serves as a trigger for investigation and management action to prevent ecological degradation. ConsistencyResolver applied 2026-03-22 21:24 UTC: LowerThreshold 50 → (check: MinAboveOptimalHigh, rationale: Removing the LowerThreshold value avoids the contradiction and aligns with the threshold being an upper guard.) ConsistencyResolver applied 2026-03-22 21:24 UTC: UpperThreshold → 50 (check: MinAboveOptimalHigh, rationale: The Notes and EvidenceStatement indicate that EC values above 50 µS/cm trigger ecological concern, so 50 should be an upper threshold, not a lower threshold.) ConsistencyResolver applied 2026-03-22 21:24 UTC: UpperThreshold → 50 (check: MinAboveOptimalHigh, rationale: The Notes and EvidenceStatement indicate that EC values above 50 µS/cm trigger ecological concern, so 50 should be an upper threshold, not a lower threshold.) ConsistencyResolver applied 2026-03-22 21:24 UTC: UpperThreshold → 50 (check: MinAboveOptimalHigh, rationale: The Notes and EvidenceStatement indicate that EC values above 50 µS/cm trigger ecological concern, so 50 should be an upper threshold, not a lower threshold.) ConsistencyResolver applied 2026-03-23 00:19 UTC: UpperThreshold 50 → (check: MinAboveOptimalHigh, rationale: Removing the UpperThreshold value from the MinimumOnly benchmark avoids form confusion and contradiction, as the upper degradation limit is already represented by the MaximumOnly benchmark.) ConsistencyResolver applied 2026-03-23 00:19 UTC: LowerThreshold → 5 (check: MinAboveOptimalHigh, rationale: To resolve the MinAboveOptimalHigh contradiction, the MinimumOnly threshold must be below the OptimalRange low (10 µS/cm). Setting LowerThreshold to 5 µS/cm aligns with the MinimumOnly form as a floor guard and avoids penalizing the optimal range.)

Related Benchmarks

Other benchmarks in the AUS-ASC-CON-WEC family.