Developing a water quality management plan
Preparation of water quality management plans for catchment waterways is a key part of the National Water Quality Management Strategy, our joint national approach to protecting and improving water quality in Australian and New Zealand waterways.
Use the Water Quality Management Framework to develop a water quality management plan. We provide advice on monitoring and assessment at each step in the framework.
Your plan will establish agreed management strategies to be implemented and adaptively managed to meet the water/sediment quality objectives required to protect community values for your catchment waterways.
Initially, you may not have local monitoring data available to use in the plan development process. For most of the early framework steps, you could use regional or national information or default guideline values (DGVs) until you have better information to represent your local system.
Monitoring data will be needed for future revisions of your water quality management plan. Collection of local monitoring data will typically occur outside the plan development process. These data can be used to refine or improve system understanding, indicators, measurement programs, water/sediment quality guideline values and water/sediment quality objectives.
Use current understanding to develop a conceptual model of key waterway processes, the issues they face and how to manage them. It will inform your decisions at subsequent steps in the framework.
Typically, you would hold technical and stakeholder involvement workshops to develop or refine the conceptual model. (The same process is used to establish community values and management goals at Step 2.)
To assist in the development or refinement of conceptual models, use existing data and scientific literature on current state and values of the waterway system and the impacts and management of existing activities.
Your conceptual model should show:
- key waterway processes
- pressures being managed and their associated stressors
- key ecosystem receptors that are important to the community values.
Use this knowledge at Step 3 to identify key indicators for the pressures, stressors and ecosystem receptors selected for use in a weight-of-evidence process for assessing and managing water/sediment quality.
Information at this step begins to inform the nature of your monitoring program.
Repeated cycles through the Water Quality Management Framework will improve your data and provide new information that can be used to refine conceptual models and improve current understanding.
Community values and more specific management goals (including level of protection) for your catchment waterways will typically be established or refined at stakeholder involvement workshops.
In some cases, jurisdictions may already have prescribed community values (and possibly management goals).
You would normally complete this step in parallel with the development or refinement of the conceptual model at Step 1.
Indicators are selected for the relevant pressures identified for the waterway system, their associated stressors and anticipated ecosystem receptors. This is consistent with using multiple lines of evidence in a weight-of-evidence process for assessing and managing water/sediment quality.
We provide use-specific quality of evidence tables to assist with the selection of different lines of evidence and their indicators.
Development of conceptual models, community values and management goals at Steps 1 and 2 forms the basis of the indicator selection. Subsequent steps set objectives for these indicators and allow tracking of progress against management strategies to achieve these objectives.
You may establish monitoring at this step to:
- test and validate relevant indicators
- design and develop or refine field sampling and laboratory methodologies (e.g. associated hazard assessment for physical and chemical stressors).
Initial monitoring data may cause you to further refine the list of selected indicators, such as where monitoring for an indicator at the required level of sensitivity is found to be impractical.
Determine the water/sediment quality guideline values for each of the relevant biological, chemical and physical indicators that will provide the desired level of protection (if applicable) for your management goals and protect your community values.
Where possible, derive or use locally relevant (e.g. site-specific, catchment) guideline values. Until these are available, use the default guideline values (DGVs) but be aware that they may not represent your local system.
If possible and necessary, establish or continue monitoring programs or appropriate laboratory or field studies to derive locally relevant guideline values.
To define the draft water quality objectives (or sediment quality objectives), select the guideline values and/or narrative statements at Step 4 for each indicator selected at Step 3 that should ensure the protection of all identified community values and their management goals (Step 2). Choose the most stringent of the guideline values for the water/sediment quality objectives.
At this stage, these are aspirational objectives that have not yet accounted for cultural, economic and social considerations (at Step 8).
Compare the water/sediment quality monitoring data for each relevant indicator with the water/sediment quality objectives (W/SQOs), together with the evidence from any additional lines of evidence.
Use the results to assess water/sediment quality, including:
- whether or not the W/SQOs have been met
- the cause and spatial extent of any change observed.
Where a new plan is being developed (not the revision of an existing plan), monitoring programs for the proposed indicators may not already be in place. You may not have any data to compare to the draft W/SQOs. In this case, you would assess the W/SQOs at Step 9, after water quality modelling data have been generated at Step 8 to assess the alternative management strategies that were considered.
Use a weight-of-evidence process to evaluate the various lines of evidence. This process evaluates the results from multiple lines of evidence across the pressures, stressors and ecosystem receptors included in the monitoring program. It is the key process by which the protection of community values is assessed.
Multiple potential outcomes are possible from a weight-of-evidence evaluation. We provide guidance on their interpretation for this use of the Water Quality Management Framework in use-specific evaluation tables.
The resulting evaluation will usually include classifying waterways in the overall plan area as:
- those that meet the W/SQOs
- those that do not meet the W/SQOs or for which adverse trends are evident
- those for which the outcome is uncertain.
The W/SQOs are deemed to be met when:
- those lines of evidence considered as essential for informing acceptable water/sediment quality are met
- results for other supporting lines of evidence are consistent with no compromise to current or future water/sediment quality.
If the W/SQOs are met, then management should focus on maintaining or improving that quality. This will require a check of any possible improvements to management strategies at Step 8, and then implementation at Step 10.
A weight-of-evidence evaluation will otherwise conclude that:
- W/SQOs are not met
- adverse trends are evident
- result is inconclusive (e.g. due to difficulties in obtaining sufficient good quality monitoring data or if there is conflicting evidence from separate lines of evidence).
In these cases, up to 3 options are available:
- formulate, assess and prioritise management strategies to improve water/sediment quality (Steps 8 to 10), and/or
- reassess the appropriateness of the water/sediment quality guideline values (Step 7), and/or
- consider selection of additional or alternative indicators or lines of evidence (Step 7).
A weight-of-evidence evaluation in a water quality management plan may require multiple cycles of monitoring and reporting before clear outcomes are identified, and before one or more of the 3 options can be implemented.
You will typically develop a water quality management plan using available information. Any improvements in required knowledge are identified during the plan development process and addressed at Steps 3 to 5 of the next planning cycle.
At this step, we identify the need to revise or add to the indicators or improve the water/sediment quality guideline values, to be addressed in the next planning cycle.
Evaluate the effectiveness of current management strategies to address the identified water quality issues and recommend possible improvements.
Formulate, assess and prioritise improved or alternative management strategies (e.g. point source discharge mitigation, catchment remediation measures, industry practice changes) on the basis of environmental considerations, as well as cultural, economic and social considerations (quadruple bottom line).
Agreement on final management strategies will require robust stakeholder involvement. This should be supported by:
- relevant monitoring
- cultural, economic and social studies
- multiple objective decision support tools (where possible).
Supportive monitoring programs include those that evaluate the effectiveness of various management practice options, as well as those that improve the accuracy of the predictive models (e.g. better calibration and validation data).
Predictive models (e.g. catchment and receiving water models) can assist you to:
- quantify water quality improvements from alternative management strategies
- assess whether or not water quality guideline objectives are met.
Your assessment of whether or not the water/sediment quality objectives (W/SQOs) are achievable is based on the information gained from Steps 6 to 8.
If the W/SQOs have been met — or are expected to be met — by one or more of the management strategies (assessed in Step 8) and are also culturally, economically and socially acceptable, go to Step 10.
If they have not been met (e.g. costs and impacts associated with the necessary improvements to meet the W/SQOs are not acceptable), go back and complete Steps 2, 4, 5, 6 and 8 again.
When repeating Step 2, request stakeholder involvement to reconsider the management goals for remediation (including level of protection). At Step 5, this will result in a set of incremental W/SQOs that are focused on improvement towards meeting the original management goals in the longer term.
For the life of the current plan, this will give you a set of W/SQOs that:
- improve current condition towards the longer-term W/SQOs
- are culturally, economically and socially acceptable to your stakeholders.
Typically, you would complete the iterations in this step at the same time as Step 8, when you are assessing the quadruple bottom line of all alternative management strategies.
Agreed management strategies are incorporated into the water quality management plan, including a suitable and agreed adaptive management process.
Your adaptive management process will include:
- action plans to implement agreed management strategies
- monitoring programs to track improvements towards meeting water/sediment quality objectives (for all indicators or lines of evidence)
- monitoring programs to establish baselines and track improvements in management practices.
You will need to establish appropriate arrangements for stakeholder involvement and reporting.
Improvements required at Steps 3, 4, 6, 7 and 8 of the Water Quality Management Framework need to be actioned and completed before the next review of the plan.