Warragamba Dam – NSW

Replacement of ageing stainless steel weirs in seepage collection tunnels, ensuring continued safety and functionality of Sydney’s primary water supply dam

The Warragamba Dam Project

Warragamba Dam, Sydney’s primary water supply reservoir, stands as the largest concrete gravity dam in Australia and one of the largest domestic water supply dams worldwide. Operated by WaterNSW, the dam’s seepage collection system is monitored through a series of weirs located within an intricate tunnel network inside its 3-million-tonne concrete structure. Recognising the need to replace and update ageing weirs, WaterNSW engaged Sixense to undertake this critical modernisation task.

The Challenges

The project involves the decommissioning of existing weirs and the installation of new, high-grade stainless steel weir systems. The remote location of the weirs deep within the dam’s labyrinthine tunnels posed significant logistical challenges. Tasks such as demolition, masonry work, concreting, formwork, waterproofing, and caulking required meticulous planning and collaboration to ensure the work met WaterNSW’s high standards.

What We’ve Delivered

Since September 2024, Sixense has installed 7 new high-grade stainless steel weir plates across key seepage collection points. This effort required innovative approaches to overcome complex access constraints and deliver high-quality results. Sixense engineers worked in close collaboration with WaterNSW, maintaining clear communication and ongoing feedback throughout the project. While the labour-intensive tasks were outside the usual scope of Sixense’s expertise, the team leveraged a systematic approach and resourceful problem-solving to successfully deliver a solution tailored to the client’s needs. By modernising these essential monitoring systems, Sixense has ensured the continued safety, functionality, and reliability of Warragamba Dam, safeguarding Sydney’s critical water supply infrastructure for years to come.