Town water security analysis

Murrumbidgee River, NSW.

Water security is important to ensure long term continuous access to reliable drinking water supply and water for sanitation. Uninterrupted long-term access to water allows communities to grow and thrive by contributing to good public health, economic development opportunities, social amenity and liveability.

The State Water Strategy sets priority actions focused on improving the security, reliability, and resilience of the state’s water resources, including town water supplies.

Water security analysis for strategic planning

Water security analysis is a key component of local water utility Integrated Water Cycle Management (IWCM) strategic planning.

Fresh water is a finite resource and is highly influenced by climate and weather patterns. Without robust water security planning and adequate investment in water infrastructure, a community can be exposed to threat of drought, severe water restrictions, or even water supply failure.

Town water security analysis assesses the long-term risk a regional town water supply scheme faces in accessing a reliable water source. This access risk is assessed considering the frequency and duration of water restrictions and the availability of water in the system to meet demand under moderate restrictions.

The department’s 2013 draft Assuring future urban water security – Assessment and adaption guidelines for local water utilities (PDF, 2180.13 KB) is the key guidance document for assessing water security and sizing of water supply schemes that balances the customer expectations (levels of service) and cost of water supply.

Regional Water Strategies data for town water security analysis

The department is preparing 12 Regional Water Strategies that enhance understanding of risks to future water availability. The strategies will enable better planning and management of water supplies across the state.

The regional water strategies are underpinned by new climate data and modelling of water availability and reliability. This data and modelling include consideration of paleoclimate (where available) and climate change impacts in order to develop scenarios of plausible extreme climate events.

For more information visit the Regional Water Strategies.

Guidance is being developed for the use of regional water strategy data and advancements in climate understanding for town water security analysis.

Interim guidance for regulated surface water sources

This interim guidance (PDF, 122.02 KB) describes the steps for using the regional water strategy modelling generated streamflow data to analyse town water supply security risks for towns dependent on regulated water sources.

The department aims to use this guidance for pilot studies on a small number of town water schemes. With lessons from these pilots, the interim guidance will be reviewed and updated for use by local water utilities.

Guidance for unregulated surface water sources

The 2013 draft guidelines (PDF, 2180.13 KB) is the key guidance document for assessing water security and sizing of town water supply schemes dependent on unregulated surface water sources.

The department is evaluating the use of regional water strategy data and climate models for assessing town water security risks and sizing of town water supply headworks infrastructure using case studies. Interim guidance will be made available in 2022.

Interim guidance for groundwater sources

For communities depending on groundwater as a source of water, the long-term sustainable yield and drought resilience of their existing bores/borefields need to be established.

Guidance (PDF, 104.23 KB) is available on the process for developing a brief and engaging a consultant to deliver sustainable yield and drought resilience assessment for existing town water supply groundwater schemes.

The scope of works (PDF, 138.56 KB) details typical requirements that should be reviewed for appropriateness and included in the draft tender brief prepared by local water utilities. The draft tender brief should be submitted to the department for concurrence, together with the Form 1 background information document (PDF, 138.12 KB). The department to complete Form 2 (PDF, 152.36 KB) to confirm the level of input required by the department.

New water security guidelines will be developed

The department will be preparing town water security guidelines using lessons from pilot / case studies including the process for the use of regional water strategy data. The department plans to consult widely on these new guidelines. The new guidelines are expected to be released in 2023.

If you are interested in taking part in a pilot, please contact your local contact in the department’s water utilities team.