Plans to establish a desalination plant at Toukley have progressed with the exhibition of the Central Coast Water Security Plan.
The plant, capable of producing 30 megalitres of water a day, would provide the region with an additional rainfall-independent water source in the event of a severe and prolonged drought.
Central Coast Council previously obtained planning approval for a 20 megalitre a day desalination scheme as part of its Millennium Drought response.
The development of the Central Coast Water Security Plan identified that the previous approved scheme required a different seawater intake location and a larger plant.
The council is undertaking site selection for a seawater intake structure and transfer pump station for the Toukley plant, before it develops a concept design and obtains planning approvals.
"This allows council to better understand the time and cost required to construct a desalination plant at Toukley - if the plant is required in response to a future severe and prolonged drought," the council said.
"We need to do this planning work now, to ensure that we can responsibly delay triggering more expensive detailed design and construction activities until a later stage during a potential future drought."
The draft Central Coast Water Security Plan, which is open for public comment until September 28, also includes a purified recycled water scheme at Wyong South and upgrades to three main bore fields at Ourimbah, Mangrove Creek and Woy Woy.
"We now have an improved understanding of rainfall and streamflow trends, there have been advances in technology and changes in our regulatory environment as well as updated population and water demand forecasts," the council's director of water and sewer Jamie Loader said.
"The vision is to provide a resilient and sustainable water future that promotes regional health, prosperity and is supported by the community.
Twenty five kilometres north of Toukley, Hunter Water is building a $530 million desalination plant of a similar capacity at Belmont.
Hunter Water has also confirmed earlier this year that the desalination plant would add an extra $90 a year to the average water bill.
The Independent Pricing and Regulatory Tribunal is yet to approve the increase, however, Hunter Water's analysis shows the desalination plant remains the most cost-effective option to support Hunter communities during drought.
"I think the community will appreciate that investment is required to ensure that we can provide water to the community through all conditions, including drought," Hunter Water managing director Darren Cleary said in January.
Construction, which is due to start next year, will create up to 215 full time equivalent jobs.
The plant is due to start operating in 2028.
While the Hunter and Central Coast manage their water supplies separately, there is capacity to transfer water via a shared pipeline.
