Level of protection

​We can define ‘level of protection’ as the degree of protection afforded to a water body based on its ecosystem condition (current or desired health status of an ecosystem relative to the degree of human disturbance).

The level of protection informs the acceptable water/sediment quality for a waterway.

In the Water Quality Guidelines, level of protection only applies to aquatic ecosystems. But it could be applied to other community values.

We select a level of protection to:

  • maintain the existing ecosystem condition, or
  • enhance a modified ecosystem by targeting the most appropriate level of condition.

You would typically decide on a level of protection for a region through a process of stakeholder involvement, by determining community values and associated management goals in the context of current ecosystem condition and the community’s long-term desires for the ecosystem. This occurs at at Step 2 of the Water Quality Management Framework.

Check with relevant local authorities in your jurisdiction who might already have established levels of protection, and possibly different categories to consider.

Ecosystem conditions and associated level of protection

We recognise 3 categories of current or desired ecosystem condition in the Water Quality Guidelines. You can specify a corresponding level of protection by using these ecosystem condition categories:

  • high conservation or ecological value systems
  • slightly to moderately disturbed systems
  • highly disturbed systems.

For each category of ecosystem condition, the Water Quality Guidelines provide specific guidance for:

  • field biological assessments undertaken in waterways
  • applications of appropriate guideline values for physical and chemical stressors, including toxicants
  • attributes and corresponding levels of protection.

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Other approaches to determining a level of protection

Our 3 simple categories of ecosystem condition and associated levels of protection form a subjective approach to viewing the continuum of disturbance across ecosystems.

Stakeholders in different jurisdictions, catchments or regions will inevitably make different judgements about current or desired ecosystem conditions.

For example, in Queensland and Western Australia​, 4 ecosystem conditions are articulated. An ecosystem regarded as highly disturbed in one area could be regarded as only slightly to moderately disturbed in a more populated region.

This is why setting levels of protection must be carried out in an open and transparent way, involving all key stakeholders, to achieve a fair and reasonable agreed outcome.

Local jurisdictions may negotiate alternative site-specific levels of protection after considering many factors, such as:

  • whether a policy of ‘no release’ (total containment) of contaminants applies
  • nature of contaminants that might reach aquatic ecosystems
  • perceived conservation or ecological values of the system, additional to those recognised in our suggested classification of ecosystem condition.

For example, greater consideration might be given to those ecosystems receiving contaminants or effluents of potentially high toxicity that are persistent in the environment (e.g. metals).

Or differing levels of protection could apply according to the anticipated capacity of an ecosystem to readily recover from impact if contamination is to be of short duration.

Reviewing levels of protection

If a system categorised as a particular ecosystem condition is assigned a certain level of protection, it does not have to remain ‘locked’ at that level in perpetuity.

The community values and management goals (including the level of protection) for a particular ecosystem should normally be reviewed after a period of time, and stakeholders may agree to subsequently adopt a different level of protection.

The concepts of adaptive management and continual improvement should always be promoted, to maximise future options for a waterway.

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