The Development of Default Guideline Values (DGVs) of Water Quality for Aquatic Ecosystems
Default Guideline Values (DGVs) of water quality for aquatic ecosystems have been developed in accordance with the National Water Quality Management Strategy (NWQMS). The default guideline values apply to the Protected Environmental Value of Protection of Aquatic ecosystems.
Default Guideline Values have been developed for High Ecological Value and Slightly to Moderately Disturbed aquatic ecosystems.
The Default Guideline Values for Slightly to Moderately Disturbed ecosystems can be used as interim guideline values for moderately disturbed ecosystems until site-specific guideline values are developed.
For the decision process and selection criteria for identifying the ecosystem condition refer to the EPA document, Technical Guidance for Water Quality Objectives (WQOs) Setting for Tasmania.
Technical Guidance for Water Quality Objectives (WQOs) Setting for Tasmania (537Kb)
Specificity of Water Quality Guideline Values
Water Quality Guideline Values can be set at varying scales of specificity dependent on data availability. The guideline values provided represent Default Guideline Values for each ecosystem type based on relevant regionalisation or classification. Where no state-level data is available then the National or international guidelines apply. Site-specific guideline values will be developed on an as needs basis.

WQG Decision Rings
Ecosystem types
Default Guideline Values of Water Quality for Aquatic Ecosystems are available for the following ecosystem types: