Environmental Values and Water Quality Objectives: 
what are they and how are they used

Summary

A framework for identifying and setting Environmental Values (EVs) and Water Quality Objectives (WQOs) is well established through the National Water Quality Management Strategy (NWQMS) and Queensland Environmental Protection (Water) Policy 1997 (EPP Water). The EPP Water includes a process for determining the Environmental Values of waterways and corresponding Water Quality Objectives, and identifies the need for appropriate consultation with the community. This process has been adopted for development of the Burdekin WQIP, as in WQIPs from other GBR catchments, and is reported in this Chapter.

Environmental Values are the qualities of waterways that need to be protected from the effects of pollution, waste discharges and other threats to ensure aquatic ecosystems are healthy and waterways are safe for community use. EVs and how they are used are defined and explained below. Environmental Values have been identified for freshwater, estuarine and marine areas of the Burdekin WQIP region in collaboration with the Queensland Environmental Protection Agency (EPA) and Great Barrier Reef Marine Park Authority (GBRMPA). Freshwater High Ecological Value (HEV) areas are also listed and described in this Chapter, while the full suite of draft freshwater EVs are presented for each of the 48 Burdekin WQIP subcatchments within the Catchment Atlas. EVs for the estuarine and marine areas of the Burdekin WQIP region and receiving waters, including identification of High Ecological Value (HEV) estuarine and marine areas, are similarly presented in this Chapter.

The use of water quality guidelines for freshwater, estuarine and marine aquatic ecosystems are described in this Chapter. Insuffiicent data are available from the Burdekin Dry Tropics NRM region to derive locally releveant guidelines for freshwater ecosystems at this time.  Consquently National and Queensland guidelines were used as default guideline values for freshwater guidelines.

Water Quality Objectives are based on the Environmental Values of water and the existing water quality guidelines that are intended to protect these values. They are measurable indicators of water quality and may be defined for a range of physical, chemical and biological parameters.  Most commonly, however, they are expressed as concentrations. Concentrations above the WQO are used to indicate a possible health or use risk and trigger a management response. EVs and their supporting WQOs can inform, guide and provide a common goal for many forms of water planning and management, and investment programs.

Water Quality Objectives for freshwater, estuarine and marine waters of the Burdekin WQIP region are presented in this Chapter. While the WQOs for the protection of estuarine, coastal and marine waters may be considered ‘final’, there is a recognised need for further information on freshwater EVs. Hence, the WQOs for freshwater reaches are considered to be draft only. The WQOs for end-of- catchment estuarine areas and the immediate receiving waters of the GBR have been used within the Burdekin WQIP to establish targeted pollutant load reductions that will protect the Environmental Values of estuarine and marine areas of the GBRWHA.