Water planning science & monitoring

Risk assessment

We have prepared risk assessments for each water resource plan area in NSW. A risk assessment is a key step in preparing water resource plans. It looks at risks to the condition and continued availability of water resources. The risk assessment is at Schedule D in each draft plan. Select the water resource plan by region which takes you to the main page for that plan. Within the ‘draft plan’ you will find Schedule D titled ‘Risk Assessment Information…’.

The risk assessment framework adopts a cause/threat/impact model. The model describes the risk pathway of impacts to a receptor. The risk level of an impact is a function of likelihood and consequence. The likelihood of a cause and threat occurring, and the consequence of the impact on the receptor. We adopted the following definitions for risk assessments in the Murray Darling Basin:

  • Likelihood: the probability that a cause will result in a threat. It is not a sign of the size of the threat, but rather conveys the probability that the threat will be significant.
  • Consequence: the loss of value for an impacted receptor.

We assessed the risk level using current strategies and rules as provided by the NSW Water Management Act 2000 and the relevant water sharing plan/s. The risk assessment outlines the management actions and mechanisms to address risks.

The figure below combines the cause/threat/impact model and likelihood/consequence. As an example, it shows risks arising from river regulation and licensed surface water extraction.

Cause, threat and impact model

For many of the Basin risk assessments, alteration to flow is the basis for likelihood. This is an outline of the modelling used in the Basin ((PDF 3.2 MB)) . The value of ecological assets and ecosystem functions is the basis for consequence. Applying the HEVAE Framework for Riverine Ecosystems ((PDF 2.5 MB)) describes the approach to mapping ecological assets.

Medium and high risk results identified in risk assessments undergo review. This determines whether these risks are adequately addressed by existing strategies. If not, they may need modifications or new strategies. In NSW, a medium or high risk does not always imply that existing rules or strategies are inadequate. The risk assessment is a 'red flag' process to provide guidance during the life of a plan. It identifies areas that may need further investigation.

Risk-based management assists water managers to prioritise and plan. This allows managers to direct resources to the factors that pose the highest risks. They can target strategies to the appropriate part of the water system.

Monitoring, evaluation and reporting

The sustainable management of our rivers and groundwater systems is our priority. Water sharing plans define the rules for sharing water between the environment and all other water users. The rules govern how water is shared to meet the needs of water dependent ecosystems, and water users including town and rural water, industry and irrigation.

Water sharing plans contain a set of environmental, economic, social, cultural and heritage objectives. Guidelines for setting and evaluating plan objectives for water management ((PDF 904.1 KB)) help us to develop objectives. The Guidelines describe how to make objectives measurable and assessable. They also describe how to align objectives to strategies within a Plan. If an objective is not met during the term of a Plan, then the Guidelines approach makes it easier to understand why. This approach also guides how to change the water sharing plan so that it is more effective in the future.

To determine how well a water sharing plan is meeting its objectives, we need monitoring. Environmental monitoring assesses the response of  water dependent ecosystems to management practices. It also looks at how different patterns of water flow affect the way rivers function. Environmental monitoring includes the river's physical form, its fringing vegetation and the organisms (e.g. frogs, fish, insects) that live in the rivers. This information gauges the health of rivers and floodplain systems. We can then assess the effectiveness of management strategies. Check out some of our monitoring, evaluation and reporting projects.

The department has worked with other agencies to develop Monitoring, evaluation and reporting (MER) Plans for each water resource plan area in NSW. These plans link to the environmental objectives of a water sharing plan. They drive the focus for monitoring activities. To see the MER Plan for each area, select the water resource plan by region which takes you to the main page for that plan. Within the ‘draft plan’ you will find a Schedule titled ‘Water Monitoring, Evaluation and Reporting’.

Increased scientific understanding helps us to allocate water more effectively. It helps us improve our evaluation of the performance of water sharing plans. Thus, it contributes to evaluating the Basin Plan. Scientific feedback makes efficient sharing of water possible.