Water Nitrate — Benchmark Detail

Benchmark Value

1 mg/L

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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The value of <1.0 mg/L stands out as the most credible and defensible benchmark. It is a real-world, measured concentration that is empirically associated with the highest possible ecological condition rating in a well-monitored urban system located within the target biome and managed using best practices.

Metric Definition:

Water nitrate concentration in urban streams as an indicator of ecological health.

Benchmark Definition:

This benchmark represents the upper limit of nitrate concentration for an 'Excellent' water quality rating in urban streams within the Temperate Grassy Woodlands & Plains biome, reflecting best-practice urban water management.

Justification:

Derived from extensive monitoring data from the ACT Catchment Health Indicator Program, linking nitrate levels to ecological condition under best-practice WSUD management.

Sources (2)

Preview of Catchment Health Indicator Program Report 2021 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,

Catchment Health Indicator Program Report 2021 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025, Journal

ANZECC/ARMCANZ (2000) Guidelines

View Source

Preview of Current understanding of the eutrophication process in Australia - ResearchGate, accessed August 17, 2025,

Current understanding of the eutrophication process in Australia - ResearchGate, accessed August 17, 2025, GreyLiterature

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

View Source

Context

Region Australia
Biome Temperate Grassy Woodlands & Plains
Land Use Urban & Developed Use
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 3
Effective From 3 Jun 2026

Notes

No lower critical threshold exists; less nitrate is unequivocally better. The benchmark defines the upper limit of a high-health state. ANZECC (2000) trigger value of 0.444 mg/L is a more sensitive early warning threshold. Concentrations above 1.4 mg/L indicate moderate degradation, and above 2.6 mg/L indicate severe degradation. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TGP-URB-WNI family.