We have identified and mapped broad spatial patterns based on biological and physical attributes in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality. This expands on the ecoregionalisation approach first introduced in the ANZECC & ARMCANZ (2000) guidelines.
Check with relevant local authorities in your jurisdiction who might have established guidance and guideline values for inland surface water and marine waterways.
Ecoregional water quality guidance for Australia and New Zealand
The Water Quality Guidelines provide physical and chemical (PC) stressor default guideline values (DGVs) for many ecoregions of Australia and New Zealand.
We provide specific advice for Australia about the jurisdictional setting, features and ecology of natural and semi-natural aquatic ecosystems in each region, indicators that may be used for biological assessment, and design considerations for conducting a monitoring and assessment program.
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Improvement on previous ecoregionalisation
The ecoregional schema in the Water Quality Guidelines is a considerable enhancement over the approach in the ANZECC & ARMCANZ (2000) guidelines:
- each type of regionalisation or ecosystem based on greater environmental (climatic–physiographic) similarity
- many more regions
- more regional PC stressor DGVs
- more biological assessment models for inland streams (e.g. AUSRIVAS, or Australian River Assessment Scheme)
- useful template for providing guidance on regional-specific management context, biological assessments and general monitoring advice.
Localised guideline values for PC stressors
Many jurisdictions have derived their own guideline values for PC stressors at a catchment, basin or physiographic level since the ANZECC & ARMCANZ (2000) guidelines. We provide links to such jurisdictional information.
It is advantageous for jurisdictions and other users to derive guideline values at even finer spatial scales than the ecoregions adopted in the Water Quality Guidelines.
Future revisions of jurisdictionally derived guideline values for PC stressors should consider the ecoregionalisation adopted in the Water Quality Guidelines to avoid any aggregation across adjoining ecoregions.
Limitations of regional referentially based guideline values for PC stressors
Referentially derived DGVs for PC stressors only provide first-pass guidance for water quality management in the absence of site-specific data and information.
Our ecoregionally based DGVs have improved on the ANZECC & ARMCANZ (2000) values but we recommend that jurisdictions and other users collect more localised reference data for site-specific derivation of guideline values from:
- strategic monitoring programs
- submissions for proposed or existing scheduled activities
- environmental quality management plans developed by proponents.
Benefits of locally derived guideline values
It is not possible to develop a universal set of DGVs and associated guidance that applies equally to all regions.
Australia and New Zealand have a wide range of ecosystem types and environments, which create enormous differences in water quality characteristics between regions. Additional environmental factors, such as local natural water quality, can significantly alter the toxicity of toxicants and PC stressors at a site, and these factors can vary considerably between sites.
This is why water and sediment quality assessments that use more localised (geographically derived) guideline values and advice targeted to the relevant local scale will always be more accurate than those using DGVs. As a general rule of thumb: the higher the spatial resolution, the more accurate the assessment.
Biological assessments are implicitly regional or site-specific because their basis is the comparison of monitoring data from sites of interest against those gathered in a baseline period and from a local reference condition of similar spatial scale.
Advice and guidance for indicator types (PC stressors and toxicants) — and derivation of DGVs for some PC stressor indicators — will be relevant at a regional scale, which is the basis of our ecoregional guidance.
Presentation of ecoregional water quality information
The Water Quality Guidelines will eventually provide specific information to assist with conducting water quality assessments in each of the estuarine, inland surface water and marine ecoregions of Australia and New Zealand. In the meantime, we are releasing:
- partial data for Australia’s marine regions
- partial data for Australia’s inland waters
- full data for New Zealand’s freshwater rivers (but only sedimentation rates for estuaries).
Regional information for Australia is presented in 3 parts.
Part 1 — General descriptions
Specific information or advice about the jurisdictional setting, features and ecology of naturally occurring aquatic ecosystems in each ecoregion, indicators that may be used for biological assessment, and design considerations for conducting an associated monitoring and assessment program.
Management context — includes general land use, economic zones, protected properties and assigned level of protection and aquatic ecosystem condition status (if undertaken by the relevant jurisdiction).
Descriptions of aquatic ecosystem types and seasonality — includes hydrology or oceanography, and general water quality features and implications for water quality assessments. General aquatic ecology descriptions comprise key ecological processes and general patterns of biological diversity and conservation significance, as well as any available conceptual models of key natural processes operating in the aquatic systems.
Part 2 — Water quality guidance and guideline values
Links to ecoregional or current jurisdictional water quality guidance or guideline values for PC stressors. These will refer predominately to guideline values for PC stressors derived from reference data. For some regions, biological-effects data has been used to derive DGVs (e.g. dissolved oxygen, salinity, turbidity). These values are described together with any similar regional or site-specific effects-based guideline values for toxicants.
Part 3 — Other advice for water quality assessments (including biological assessments)
Other regional or national guidance — conceptual models depicting causal pathways for common pressures and threats, and links to revised and new regional AUSRIVAS or derivative models for jurisdictions.
Proven indicators — successfully and routinely monitored indicators for specific pressures in different ecosystem types in the region, and links to relevant protocols or other published methods.
Under the specific regional climatic regime, monitoring strategies, techniques, and design and analysis for ecosystem types vary considerably. Recommended periods for monitoring, implications of seasonality and interannual variability in flow, water level, current and other climatic variations for monitoring, and work health and safety considerations may be provided.
Basis of ecological classification
Ecological classifications support land and water conservation management based on ecosystems by providing spatial frameworks that stratify landscapes (geographic space) into units with distinctive ecological character (Hale et al. 2012).
For water quality management, these ecological units (may be geographically independent) or ecoregions (may be geographically distinct) — and their associated ecosystem and habitat types — can provide the basis for more targeted and relevant guideline values and associated advice.
Hale et al. (2012) reviewed different approaches to aquatic ecosystem classification and regionalisation in Australia and New Zealand. We have adopted their recommendations in the Water Quality Guidelines for regionalising water quality guideline values and associated guidance.
Rivers and streams in New Zealand
Where attributes for physical and chemical (PC) stressors have not been assigned in the
National Policy Statement for Freshwater Management 2014, geographically independent classifications for rivers and streams are based on environmental characteristics for PC stressors.
Geographically independent classifications are based on environmental characteristics nested within a high-level bioregionalisation for biological assessment.
Further work is required to develop schema for non-riverine systems in New Zealand.
Surface waters in Australia
We adopted a nested approach for deriving PC stressor DGVs and selecting biological indicators, as well as advice for both types of indicator. Our approach uses the Australian National Aquatic Ecosystem (ANAE) classification for surface waters within inland (non-estuarine) waters, estuaries and marine waters: palustrine (wetlands), lacustrine (lakes), riverine (rivers and streams), floodplain, estuarine and marine ecosystems.
Inland (non-estuarine) waters
We used Australia’s 12 drainage divisions, based on major topographic features and climatic zones.
For marine waters outside the Great Barrier Reef Marine Park, we used:
- Australia’s 5 marine regions for high-level guidance on management context, ecological descriptions, biological indicator selection and other advice
- Australia’s 60 IMCRA (Integrated Marine and Coastal Regionalisation of Australia) mesoscale bioregions for derivations of a number of PC stressors.
The Great Barrier Reef Marine Park Authority provides
DGVs and guidance for the Great Barrier Reef Marine Park.
Both the marine regions and the IMCRA mesoscale bioregions are derived from biological and physical information.
ANZECC & ARMCANZ 2000,
Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.
Hale, J, Butcher, R, Collier, K & Snelder, T, 2012,
ANZECC/ARMCANZ Water Quality Guidelines Revision: Ecoregionalisation and Ecosystem Types in Australian and New Zealand Marine, Coastal and Inland Water Systems, report prepared for the Department of Sustainability, Environment, Water, Population and Communities, Canberra.