Water supply planning

Economic growth and a drying climate are major challenges for water resource management and water supply development.

The Department of Water and Environmental Regulation carries out water supply planning to identify water demand-supply gaps well before they occur and identify future supply options. We also:

provide technical and policy advice to government
identify development 'hot spots' and major water supply options to support growth
work with government and self-managed water supply stakeholders to ensure demand projections are considered and supply options are planned and implemented in due time
work with water service providers to improve the security of town water supplies.

The department provides public information and advice to government on three levels – state, regional and local.

State level

Our new water demand and supply model improves the accuracy of water demand and supply forecasts across the state. This allows us to highlight emerging issues, taking into account trends in economic growth and predictions of a drying climate.

Regional level

The Department of Water and Environmental Regulation engages with planning and development agencies to ensure an integrated approach to regional development, land use planning, water planning and infrastructure priorities. We published the Pilbara regional water supply strategy in 2013, the Great Southern regional water supply strategy in 2014 and the Mid West regional water supply strategy in April 2015.

Local level

The Department of Water and Environmental Regulation works with government agencies and other organisations to advise on water supply options for developments that are of strategic significance to the state, such as the Ord River irrigation area expansion and heavy industry in Kwinana (Western Trade Coast heavy industry water supply strategy, 2016). Advice may include pre-feasibility and feasibility assessments of water supply options (e.g. Myalup irrigated horticulture managed aquifer recharge prefeasibility study, 2018).

We regulate the sustainable take of water and encourage efficient use of groundwater and surface water resources to meet additional demand. Future water supply options will be identified when this is no longer feasible. New water sources may include those that are not of drinking water quality, but can be utilised in other ways that are ‘fit-for-purpose’, such as using recycled wastewater to irrigate sporting ovals.

Planning hierarchy

Water supply planning can be carried out at different geographic and time scales and at different levels of detail.

The strategic scale covers large geographic areas and looks further into the future, where a wider range of options can be considered. At smaller scales and closer timeframes, fewer options may be available or appropriate, and the costs and benefits can be assessed in greater detail and with more certainty.

Roles and responsibilities

In addition to our legislative functions, the Department of Water and Environmental Regulation coordinates cross-agency advice on future water demand and water supply options, including:

policy direction and advice on the best use of the state's water resources
advice on how much water is available and how demand will change in the short, medium and long-term
advice on water supply options to meet current and future water needs.

Water service providers and self-supplied water users also have roles and responsibilities in water supply planning and development.

	Department of Water and Environmental Regulation	Water service providers	Self-supplied water users
Geographic scale of planning	State, regional and local	Regional scheme or development	Site and property
Water uses covered	All water uses	Town scheme water (potable, domestic, commercial, institutional, industrial) Irrigation scheme water (non-potable, agriculture)	Mining, agriculture, industry, domestic, commercial, parks and gardens
Scale and range of water supply options assessed	All realistic major options meeting legislative requirements and government policy objectives	Range of feasible options leading to a preferred option to meet policy and commercial objectives	Small range or preferred option to meet commercial objectives or private needs
Type of water resource investigations	Water yield, quality and sustainability of water resources	Water yield and quality at a range of locations to meet licensing requirements and scheme needs	Water yield and quality at specific locations to meet licensing requirements and commercial or private needs
Role in supplying water	Setting sustainable limits on water abstraction Licensing abstraction from water resources	Constructing source and scheme infrastructure and supplying customers	Constructing infrastructure for private use