When setting water quality objectives, the community and other stakeholders should define what they want and need to protect in their waterway. To do this, the users need to identify the ‘environmental values’ (EVs) of their water resources. EVs are those qualities of the waterway or groundwater aquifer that make it suitable to support particular aquatic ecosystems and human uses. EVs require protection from the effects (both real and potential) of pollution, waste discharges, and waste deposits. A given water body will have at least one EV and, in most cases other human uses will also apply.
EVs are the same as the water related Critical Assets (defined in NAPSWQ and NHT). They are known as Protected Environmental Values (PEVs) in Tasmania, and Beneficial Uses in Victoria and the Northern Territory.
The Water Quality Guidelines identify the following EVs:
|Supporting pristine or modified Aquatic Ecosystems – see details of three possible ‘Levels of Protection’ (below)
|High conservation/ecological value systems (HCV)
|These are systems that are largely unmodified or have undergone little change. They are often found within national parks, conservation reserves or inaccessible locations. Targets for these systems aim to maintain no discernable change from this natural condition (i.e. no physical, chemical and biological change).
|Slightly to moderately disturbed systems (SMD)
|These systems have undergone some changes but are not considered so degraded as to be highly disturbed. Aquatic biological diversity may have been affected to some degree but the natural communities are still largely intact and functioning. An increased level of change in physical, chemical and biological elements of these systems is to be expected.
|Highly disturbed systems (HD)
|These are degraded systems likely to have lower levels of naturalness. Such systems may still retain some ecological or conservation values that require protecting. Targets for these systems are likely to be less stringent and may be aimed at retaining a functional but highly modified ecosystem that supports other environmental values also assigned to it (e.g. primary industries).
|Irrigating crops such as sugar cane, Lucerne , etc.
|Water for Farm Use such as in fruit packing or milking sheds etc.
|Water for Aquaculture such as barramundi or red claw farming
|Human Consumption of wild or stocked fish or crustaceans
|Recreation and Aesthetics
|Primary recreation with direct contact with water such as swimming or snorkelling
|Secondary recreation with indirect contact with water such as boating, canoeing or sailing
|Visual appreciation with no contact with water such as picnicking, bushwalking, sightseeing
|Raw drinking water supplies
|Water for Industrial Use such as power generation, manufacturing plants
|Cultural and spiritual values