coNEXA to supply recycled water to NEXTDC's S4 Sydney in $250m project

SA-based infrastructure investor coNEXA will supply up to 16 million litres of recycled water a day to NEXTDC's S4 Sydney data centre at Horsley Park under a $250 million expansion of its AquaNet recycled water network, with construction set to begin next month.

The water will come from coNEXA's Fairfield recycled water plant in Western Sydney.

The company said it is believed to be the largest recycled water connection to a data centre in Australia.

The project has approval from the Independent Pricing and Regulatory Tribunal (IPART), with first water flow expected in late 2027. It is fully privately funded, with no government capital contribution.

Up to 5.8 billion litres of water a year that would otherwise be discharged to the ocean will be reused. The company said the project will also remove the wastewater equivalent of up to 35,000 homes from a constrained sewerage network.

For NEXTDC, the recycled water supply is central to S4 Sydney's efficiency targets. Once fully developed, the facility is designed to deliver up to 365MW of IT capacity in a Tier IV-targeted configuration for cloud, AI, enterprise and government customers.

At full IT load, the data centre is designed for a power usage effectiveness (PUE) of 1.125 - more than 25% below the 2026 global average, according to the Uptime Institute.

"Data centres are essential to a thriving digital economy, and with that comes a responsibility to use resources carefully. Cooling S4 Sydney with AnywhereNow's recycled water puts that responsibility into operation," said Jeff Van Zetten, chief engineering and design officer at NEXTDC.

Kurt Dahl, chief executive of coNEXA, said NEXTDC's commitment to S4 Sydney had unlocked the scale needed to build the first stage of a network that would serve broader Western Sydney industry and community users over time.

"NEXTDC's commitment to S4 Sydney unlocks the scale and demand to build the first stage of a network that will serve more of Western Sydney industry and the community over time," Dahl said.

The AquaNet expansion is expected to support up to 200 construction jobs in Western Sydney, as well as ongoing operational roles. The expanded network will also be available to other industry users and local councils, including for irrigation of public open spaces.

"This is exactly the type of project we envisioned when we released the NSW Data Centre Guidelines. Instead of sending billions of litres out to sea each year, we're putting that water to productive use and building infrastructure that can support communities and industry for decades to come,” said NSW Minister for Water Rose Jackson.

AquaNet was established following the Millennium Drought and has supplied recycled water to Western Sydney businesses and industry since 2011.