The Woronora Filtration Plant HV Upgrade involved the replacement of existing 33kV High Voltage Switchgear, as well as subsequent upgrades to the HV cable network, SCADA system, earthing system, and operational/maintenance capabilities. Fredon Infrastructure NSW was engaged to carry out the essential HV infrastructure upgrade at the plant, which supplies water to areas south of the Georges River, including Sutherland, Engadine, and Bundeena.

The Woronora Treatment Plant filters water supplied from the Woronora Dam, with a maximum capacity of 160 megalitres per day, and plays a critical role in maintaining water supply to the region.

Our works involved managing the HV upgrade, including the design, procurement, installation, and, commissioning works; specifically:

• Supply and installation of new 3-panel 33kV Switchgear
• Disconnection, dismantling, and removal of the existing 3-panel 33kV switchgear
• Replacement and reconnection of 2 x transformer cables to the new 33kV switchboard
• Re-connection of existing control cabling to the new 33kV switchboard
• Provision of 4 x 500kVA temporary generators, fuel tank, remote monitoring, transport, and cable connections, as well as management of temporary refuelling
• Testing and commissioning of the new 33kV switchgear
• Update of existing ISMP and switching protocols

This was completed within a strict two-week outage window, in which power needed to be maintained to the remainder of site via temporary generators which were also installed by Fredon.

Woronora Filtration Plant HV Upgrade was Highly Commended and recognised as a Finalist at the 2025 NECA NSW Excellence Awards in the Industrial – Small Project category.