Queensland environmental values (EVs) and water quality objectives (WQOs)

• Identifying local environmental values (EVs), management goals and water quality objectives (WQOs) for Queensland’s tidal and non-tidal waters consistent with requirements of the Environmental Protection (Water and Wetland Biodiversity) Policy 2019.
• Including final materials in schedule 1 of the Environmental Protection (Water and Wetland Biodiversity) Policy, where they can be used in a range of condition assessment, planning and development assessment activities

The Queensland Government works with communities (including industry and commerce sectors) in partnership with Regional Natural Resource Management (NRM) groups and local governments to develop environmental values (EVs) and water quality objectives (WQOs) for Queensland waters.  Once approved by Government, these become a point of reference for water quality in Queensland.

EVs for water are the qualities that make it suitable for supporting aquatic ecosystems and human uses. EVs define the human uses of the water, (such as drinking water, irrigation, aquaculture, recreation, cultural/spiritual values), and aquatic ecosystem health. Several EVs may be identified for a particular water, and different waters may have different combinations of EVs. Stakeholder input is an important component of the process to identify EVs. Aquatic ecosystem health is an EV of all Queensland waters.

Water quality guidelines are technically derived numerical measures (e.g. concentrations) or descriptive statements to protect EVs. They are based on best-available science, local water quality data (where available) and form the technical basis for water quality objectives (WQOs).  Examples of national guidelines include Australian and New Zealand Guidelines for Fresh and Marine Water Quality, and those by the National Health and Medical Research Council (NHRMC), e.g. for recreation and drinking waters. An example of state guidelines is the Queensland Water Quality Guidelines.

Water quality objectives (WQOs) are the quantitative measures or narrative statements established to protect the EVs of waters. WQOs are derived from site-specific scientific studies, technical guideline sources (refer paragraph above), and other documents published by recognised entities.  They may be modified by social and economic factors.

Water quality data from various sources (e.g. government, science providers, industry, NRM bodies) is collected and reviewed as part of the process to establish local WQOs.

EVs are identified to protect waters from the effects of habitat alteration, waste releases, contaminated runoff and changed flows, to ensure healthy aquatic ecosystems and waterways that are safe for community use. All tidal and non-tidal waters, including wetlands, lakes and groundwater, have EVs. The suite of EVs is listed in the following section. Aquatic ecosystem health is an EV of all Queensland waters.

For the aquatic ecosystem EV, there are four levels of protection according to the current condition of the waters being assessed, i.e. high ecological value (HEV), slightly disturbed (SD), moderately disturbed (MD) and highly disturbed (HD). Each level of protection is assigned a specific management intent. For HEV waters, the management intent is to maintain natural values/condition, and WQOs are set accordingly. For waters identified as slightly disturbed, the intent is to progressively improve them towards the HEV condition.

WQOs are expressed in various ways, including concentrations, loads (e.g. tonnes/year), and biological measures. Subject to available data, the WQOs may define measures for the physical and chemical characteristics of the water, such as nitrogen content, dissolved oxygen, turbidity, toxicants (e.g. metals, pesticides), and biological characteristics such as in-stream biota (fish, macroinvertebrates, aquatic macrophytes), seagrass extent and distribution, coral extent and distribution, and groundwater stygofauna.

EVs include:

• Aquatic ecosystems (high ecological/conservation value waters, slightly disturbed waters, moderately disturbed waters, highly disturbed waters)
• Cultural and Spiritual values
• Irrigation
• Farm water supply/use
• Stock watering (e.g. cattle, sheep)
• Aquaculture
• Human consumers of aquatic foods (may include oystering)
• Primary recreation
• Secondary recreation
• Visual recreation
• Drinking water supply
• Industrial use

Different EVs may have different water quality indicators of relevance. For the Aquatic Ecosystem EV, indicators include:

• Physical and chemical indicators such as pH, nutrients, suspended solids, water clarity, salinity, dissolved oxygen.
• Biological indicators such as in-stream biota (fish, macroinvertebrates, aquatic macrophytes), seagrass extent and distribution, coral extent and distribution, groundwater stygofauna.
• Toxicant indicators (e.g. metals, industrial chemicals, pesticides). The guideline values for toxicants are determined by direct testing of the impacts (both lethal and sub-lethal) of the toxicant on target organisms. These are typically based on national (ANZG) toxicant guideline sources.

    Additional considerations include:

• Physical form indicators such as beds, banks, in-stream habitat, refuge waterholes and ground cover).
• Habitat indicators such as measures of the health of the riparian zone such as width, continuity, species composition.
• Hydrology indicators and environmental flows such as measures of alteration to flow, changes to peak or baseflow, changes in seasonality, changes to groundwater levels.

Waterway uses and values are identified based on stakeholder inputs, land and water use information and other applicable sources.  Ecosystem and habitat information is reviewed from available sources.

Water quality data needs to meet certain quality assurance/quality control standards if they are to be used in the EVs/WQOs process.  These are established in the Queensland water monitoring and sampling manual (see links below), which is the primary reference document in Queensland covering physico-chemical and biological monitoring and analysis activities.

Water quality datasets are analysed, categorised and used in derivation of water quality guidelines, in accordance with the draft guide Deciding aquatic ecosystem indicators and local water quality guidelines (see links below).

The development of the EVs and WQOs requires local stakeholder input, high level expert knowledge, spatial and non-spatial data, statistical analyses, assessment, database management and consultation.

A database platform for data storage, manipulation and values assessment, a Geographic Information System (GIS) platform for result presentation and interpretation.

EVs and WQOs for a defined area, including mapping supported by GIS files.  These are available from the DES Environmental Protection (Water and Wetland Biodiversity) Policy website (also see Case studies section below).

• Criteria against which water quaility can be compared for specific areas
• To inform environmental compliance, policy, licensing and approvals
• Report cards and other mechanisms to measure water quality change over time (where assessment repeated) at a catchment scale (monitoring)
• Development assessment
• Coastal management
• Water plans
• Resource operation plans
• Planning schemes and matters of state significance
• Investment strategies
• On-ground works
• Priority setting
• Urban stormwater management

Outputs relevant to natural resource managers including regional NRM bodies, State government agencies, Local government, consultants, water corporations and industry.

• Based on robust quantitative data at a catchment/landscape scale for many regions
• Provides the criteria and metrics for protecting specific environmental values
• Strong reliance on stakeholder inputs and knowledge
• A wide range of biological and physico-chemical parameters are used in the assessment
• Direct links to policy and legislative processes
• Widely applicable to all water types (fresh, estuarine, coastal/marine)
• Ability to develop WQOs for different flows (ambient, event) or seasons (wet, dry) where data available.

• Data limitations: local water quality data may not be available in all waters, requiring use of best available alternative source material (adjacent catchment data, technical guidelines, etc)
• Indicators: Water quality data has historically been focussed on physico-chemical indicators. WQOs using biological / habitat data are evolving.
• Reference sites: Natural (unimpacted) reference site data is limited. Alternative methods have been established to derive WQOs based on best available (modified) data (refer Deciding aquatic ecosystem indicators and local water quality guidelines.)
• Data analysis: review and treatment of water quality datasets (including quality assurance checks) requires scientific expertise
• Timeframe: stakeholder identification, consultation, and feedback, coupled with scientific and technical inputs does not take place quickly.

This page should be cited as:

Department of Environment, Science and Innovation, Queensland (2021) Queensland environmental values (EVs) and water quality objectives (WQOs), WetlandInfo website, accessed 30 August 2024. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/resources/tools/assessment-search-tool/queensland-environmental-values-evs-and-water-quality-objectives-wqos/