Water Nitrate — Benchmark Detail - Nature Index

Benchmark Value

1.65 mg/L

Range: 0.01 to 1.65 mg/L

Thresholds: Lower: —, Upper: 1.65

Optimal Range: 0.01 to 1.65

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MaximumOnly Guard Point Guard MaximumOnly Guard

Evidence & Context

The 80th percentile value of 1.65 mg/L NO3²0b²21N represents the upper boundary of concentrations expected in healthy, non-impacted groundwater systems across the country.

Metric Definition:

Water nitrate concentration as NO3²21N in groundwater representing the best available ecological condition in minimally impacted systems.

Benchmark Definition:

This benchmark represents the upper limit of nitrate concentration in groundwater expected in healthy, minimally impacted semi-arid grazing systems in Australia, indicating the best available ecological condition.

Justification:

This value is consistent with and triangulated by other relevant data sources including field studies and runoff data from well-managed grazing trials.

Sources (5)

Preview of Establishing riverine nutrient criteria using individual taxa thresholds, accessed August 8, 2025

Establishing riverine nutrient criteria using individual taxa thresholds, accessed August 8, 2025 Journal

Establishing riverine nutrient criteria using individual taxa thresholds - ResearchOnline@JCU, accessed July 25, 2025,

Preview of Full article: Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters - Taylor & Francis Online

Full article: Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters - Taylor & Francis Online

Full article: Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters - Taylor & Francis Online, accessed August 1, 2025

Preview of Herbicides, pesticides and nutrients in the Tindall aquifer, Katherine ...

Herbicides, pesticides and nutrients in the Tindall aquifer, Katherine ... Journal

Herbicides, pesticides and nutrients in the Tindall aquifer, Katherine ..., accessed July 10, 2025,

Preview of Nutrient loss and water quality under extensive grazing in the upper ...

Nutrient loss and water quality under extensive grazing in the upper ... Journal

Evidence of Large-Scale Chronic Eutrophication in the Great Barrier Reef: Quantification of Chlorophyll a Thresholds for Sustaining Coral Reef Communities - PubMed Central, accessed July 18, 2025,

Preview of The Wambiana grazing trial | FutureBeef, accessed July 19, 2025,

The Wambiana grazing trial | FutureBeef, accessed July 19, 2025, Journal

FutureBeef. (2011). The Wambiana grazing trial: Key learnings for managing for rainfall variability and land condition in northern grazing lands. Meat & Livestock Australia.

Supporting Sources (29)

Additional references from the underlying research that informed this benchmark.

Preview of 1.1.7.1 Ecological systems | Bioregional Assessments, accessed July 13, 2025,

1.1.7.1 Ecological systems | Bioregional Assessments, accessed July 13, 2025,

Contextual Support Government

NVIS Fact sheet MVG 19 – Tussock grasslands, accessed July 13, 2025

Preview of B.ERM.0108 - Wambiana: Grazing strategies and tools to improve profitability and land condition | Meat & Livestock Australia - MLA, accessed July 10, 2025,

B.ERM.0108 - Wambiana: Grazing strategies and tools to improve profitability and land condition | Meat & Livestock Australia - MLA, accessed July 10, 2025,

Contextual Support GreyLiterature

Wambiana : Grazing strategies and tools to improve profitability and ...

Preview of Brigalow Belt - Wikipedia, accessed July 10, 2025,

Brigalow Belt - Wikipedia, accessed July 10, 2025,

Contextual Support GreyLiterature

Brigalow Belt - Wikipedia, accessed July 10, 2025,

Preview of Can extension programs improve grazing management in rangelands: a case study in Australia's Great Barrier Reef catchments - CSIRO Publishing, accessed July 10, 2025,

Can extension programs improve grazing management in rangelands: a case study in Australia's Great Barrier Reef catchments - CSIRO Publishing, accessed July 10, 2025,

Contextual Support Journal

Can extension programs improve grazing management in rangelands: a case study in Australia's Great Barrier Reef catchments - CSIRO Publishing, accessed July 18, 2025,

Preview of Cattle and Australia's water supply - MAHB, accessed July 10, 2025,

Cattle and Australia's water supply - MAHB, accessed July 10, 2025,

Contextual Support GreyLiterature

Cattle and Australia's water supply - MAHB, accessed July 10, 2025,

Preview of Controls on species distribution and biogeochemical cycling in nitrate-contaminated groundwater and surface water, southeastern Australia - PubMed, accessed July 10, 2025,

Controls on species distribution and biogeochemical cycling in nitrate-contaminated groundwater and surface water, southeastern Australia - PubMed, accessed July 10, 2025,

Contextual Support Journal

Controls on species distribution and biogeochemical cycling in nitrate-contaminated groundwater and surface water, southeastern Australia - PubMed, accessed July 10, 2025,

Preview of Environmental Factors Affecting Australia's Livestock Industries - MLA, accessed August 8, 2025

Environmental Factors Affecting Australia's Livestock Industries - MLA, accessed August 8, 2025

Contextual Support Journal

Environmental Factors Affecting Australia's Livestock Industries - MLA, accessed July 10, 2025,

Preview of Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025,

Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025,

Cross Reference Journal

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

Preview of final report - FutureBeef, accessed July 10, 2025,

final report - FutureBeef, accessed July 10, 2025,

Contextual Support Journal

final report - FutureBeef, accessed July 10, 2025,

Preview of Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,

Guidance document for assessing and managing water quality in temporary waters, accessed July 16, 2025,

Methodology Source Journal

Guidance document for assessing and managing water quality in temporary waters, accessed July 10, 2025,

Preview of Land management for graziers | Business Queensland, accessed August 8, 2025

Land management for graziers | Business Queensland, accessed August 8, 2025

Contextual Support Government

Reducing the impacts of grazing on water quality - EPA Victoria, accessed July 19, 2025,

Preview of Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Contextual Support GreyLiterature

Soil Health and Regenerative Agriculture - Southern Queensland Landscapes, accessed July 27, 2025,

Preview of Livestock drinking water guidelines, accessed July 10, 2025,

Livestock drinking water guidelines, accessed July 10, 2025,

Regulatory Framework Journal

Livestock drinking water guidelines, accessed July 10, 2025,

Preview of Memorandum - Nitrate guideline values in ANZECC 2000, accessed August 8, 2025

Memorandum - Nitrate guideline values in ANZECC 2000, accessed August 8, 2025

Contextual Support Journal

Hickey, C. (2002). Nitrate guideline values in ANZECC 2000. Memorandum MFE02237 prepared for Ministry for the Environment (New Zealand). NIWA Client Report: HAM2002-126.

Preview of Microbial Biogeochemical Cycling of Nitrogen in Arid Ecosystems - PMC - PubMed Central, accessed July 10, 2025,

Microbial Biogeochemical Cycling of Nitrogen in Arid Ecosystems - PMC - PubMed Central, accessed July 10, 2025,

Contextual Support Journal

Microbial Biogeochemical Cycling of Nitrogen in Arid Ecosystems - PMC - PubMed Central, accessed July 10, 2025,

Preview of Nitrate and nitrite | Australian Drinking Water Guidelines - NHMRC, accessed August 8, 2025

Nitrate and nitrite | Australian Drinking Water Guidelines - NHMRC, accessed August 8, 2025

Regulatory Framework Government

Water quality guidelines - Queensland Environment Department, accessed July 31, 2025,

Preview of Nitrate in drinking water - WA Health, accessed August 8, 2025

Nitrate in drinking water - WA Health, accessed August 8, 2025

Regulatory Framework Government

Nitrate in drinking water - WA Health, accessed July 10, 2025,

Preview of Nitrate leaching from temperate perennial pastures grazed by dairy cows in south-eastern Australia - ResearchGate, accessed August 8, 2025

Nitrate leaching from temperate perennial pastures grazed by dairy cows in south-eastern Australia - ResearchGate, accessed August 8, 2025

Contextual Support Journal

(PDF) Nitrate leaching from temperate perennial pastures grazed by ..., accessed July 10, 2025,

Preview of NVIS Fact sheet MVG 13 – Acacia open woodlands - DCCEEW, accessed July 13, 2025,

NVIS Fact sheet MVG 13 – Acacia open woodlands - DCCEEW, accessed July 13, 2025,

Contextual Support Journal

NVIS Fact sheet MVG 13 Acacia open woodlands - DCCEEW, accessed July 10, 2025,

Preview of Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters - PMC - PubMed Central, accessed July 26, 2025,

Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters - PMC - PubMed Central, accessed July 26, 2025,

Cross Reference Journal

Reference conditions and threshold values for nitrate-nitrogen in ..., accessed July 25, 2025

Preview of Regen Ag #9- Nurture the Water Cycle - Dirty Clean Food

Regen Ag #9- Nurture the Water Cycle - Dirty Clean Food

Contextual Support GreyLiterature

Water Quality Guidelines Level of protection, accessed July 10, 2025,

Preview of Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025

Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025

Contextual Support Journal

NCC: Regenerative Agriculture and Soil Health - Wet Tropics Plan, accessed July 27, 2025,

Preview of Semi-arid woodlands (grassy sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )

Semi-arid woodlands (grassy sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )

Contextual Support Government

Temperate Grasslands - Greening Australia

Preview of Semi-arid woodlands (shrubby sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )

Semi-arid woodlands (shrubby sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )

Contextual Support Government

Semi-arid woodlands (grassy sub-formation) | NSW Environment, Energy and Science, accessed July 12, 2025, )

Preview of Southeast Australia temperate savanna - Wikipedia, accessed August 4, 2025

Southeast Australia temperate savanna - Wikipedia, accessed August 4, 2025

Contextual Support

Southeast Australia temperate savanna - Wikipedia

Preview of TERN data assist government and industry-led sustainable grazing practices in Great Barrier Reef catchments - Terrestrial Ecosystem Research Network, accessed on June 5, 2025

TERN data assist government and industry-led sustainable grazing practices in Great Barrier Reef catchments - Terrestrial Ecosystem Research Network, accessed on June 5, 2025

Contextual Support Government

TERN data assist government and industry-led sustainable grazing practices in Great Barrier Reef catchments, accessed July 18, 2025,

Preview of Water availability - A physiological constraint on nitrate utilization in plants of Australian semi-arid mulga woodlands - UQ eSpace, accessed July 10, 2025,

Water availability - A physiological constraint on nitrate utilization in plants of Australian semi-arid mulga woodlands - UQ eSpace, accessed July 10, 2025,

Contextual Support Journal

Water availability - A physiological constraint on nitrate utilization in plants of Australian semi-arid mulga woodlands - UQ eSpace, accessed July 10, 2025,

Preview of Water quality and the grazing animal - PubMed, accessed July 30, 2025,

Water quality and the grazing animal - PubMed, accessed July 30, 2025,

Contextual Support Journal

Water quality and the grazing animal - PubMed, accessed July 10, 2025,

Preview of Woodlands - DCCEEW, accessed August 5, 2025,

Woodlands - DCCEEW, accessed August 5, 2025,

Contextual Support

Woodlands - DCCEEW, accessed May 19, 2025

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Livestock Grazing & Pasture
Assessment Conservation Target
Vegetation Shrubland
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 17 Mar 2026

Notes

There is no evidence for a lower critical threshold; these ecosystems are primarily water-limited, not nitrogen-limited, and low nitrate in water indicates a healthy, nutrient-retentive system. The upper detrimental threshold is defined as any concentration consistently exceeding this 1.65 mg/L benchmark, which signifies a departure from the reference state and an increased risk of ecological harm (e.g., eutrophication). Ecotoxicological data suggest significant risk to aquatic biodiversity may emerge as Dissolved Inorganic Nitrogen approaches and exceeds ~1.3 mg/L. The optimal range for high ecological health is therefore considered to be from natural background levels up to the 1.65 mg/L benchmark.