Risk management will increasingly become a core process in water planning. Where water planning intends to meet environmental, economic and social objectives, activities and processes that put these objectives at risk need to be managed. The types of activities and processes are typically those that reduce water availability, for example, the occurrence of extended drier periods and changes in land use. However, other activities that do not affect water availability may still affect plan objectives, such as water quality, in-stream and near stream structures, and information gaps.
The risk management approach is set out as a standard in AS/NZS ISO 31000:2009 Risk management - Principles and guidelines and includes setting context and objectives, identifying threats, assessing and evaluating the level of risk to objectives, and treating the risk. These steps are monitored and periodically reviewed.
Assessment of risks to Murray-Darling Basin shared water resources
A strategy to share Murray-Darling Basin (MDB) water between the environment and consumptive water users, as well as between the basin states, was developed based on estimates of water availability from the long-term historical record. Based on concerns of reduced stream flow from growing consumptive usage, the Murray-Darling Basin Ministerial Council Cap on Diversions was implemented to limit the amount of water being extracted from the MDB rivers. Attention was then directed to the processes and activities reducing the amount of water entering the rivers, and how this would affect downstream water users and in-stream flows.
A number of activities and processes which posed risks to water availability in the MDB were identified, including:
- climate change
- increase in hillside farm dams
- increase in plantation forests
- increases in groundwater usage
- reductions in irrigation return flows.
Risk assessment strategy
The Risks to Shared Water Resources Program was set up by the then Murray-Darling Basin Commission (now the Murray-Darling Basin Authority) between 2006-2008 with full participation of the Australian, New South Wales, Victorian, Queensland, South Australian and ACT Governments to develop and implement a Murray-Darling Basin Risks Strategy.
A key element of the strategy was for the member states to submit annual reports of priorities and responses to the Murray-Darling Basin Authority Independent Audit Group using a consistent risk assessment framework, based on Risk Management standards.
Risks to all water entitlement holders and key environmental assets in the regulated parts of the NSW MDB were assessed, using results from the CSIRO-led Murray-Darling Basin Sustainable Yield Project (MDBSYP). The assessment was based on estimated changes to a baseline level of water availability for 2030 conditions, taking into consideration projections of climate change and increases in groundwater usage, plantation areas and hillside farm dams.
Risk assessment results - 2008
The NSW Office of Water undertook the Assessment of risk to NSW Murray-Darling Basin shared water resources - 2008 (PDF 1.2 MB) with assistance from the NSW Department of Environment, Climate Change and Water and Industry & Investment NSW. The assessment concluded that, with the exception of projected climate change, other activities are not expected to account for significant additional volumes of water between 2005 and 2030, and therefore do not present a significant risk to environmental assets or to water access entitlement holders at a valley or basin scale, and do not present a strong case for change in current policies.
The results from this assessment based on the MDBSYP-produced results are materially different to earlier estimates commissioned by MDBC, published by CSIRO in the 2006 report Risks to the Shared Water Resources of the Murray-Darling Basin. Reasons for these differences include:
- better advice on likely increases in areas of future plantation forests
- improved estimates for volumetric growth in farm dams
- changes in NSW Government policy to limit the potential for growth in groundwater usage.
Groundwater dependent ecosystems guidelines
Risk assessment guidelines for groundwater dependent ecosystems have been developed to manage land and water use activities that can affect groundwater dependent ecosystems. The guidelines were developed as part of the National Water Commission Coastal Groundwater Dependent Ecosystem Project. The guidelines have been developed by the NSW Office of Water and the Office of Environment and Heritage, Department of Premier and Cabinet, to assess the risk of potential and actual impacts of proposed activities on GDEs in accordance with relevant legislation.