We're upgrading the dam infrastructure at Cardinia Reservoir to ensure its future as a safe and resilient water source for Melbourne. The upgrade is as part of our proactive management of our water supply reservoirs.
Cardinia Reservoir is Victoria’s second largest reservoir and is a crucial source of water for south-east Melbourne. It can hold 287 GL of water – approximately 15% of our water supply.
We’re undertaking vital upgrades to ensure Cardinia Reservoir can continue to provide water to Melbourne’s growing population, while meeting the highest safety standards.
Cardinia Reservoir will continue to operate within Melbourne Water’s water supply system throughout the upgrade works.
Cardinia Reservoir was constructed between 1970 and 1973 to the best standards of the day. Since then, dam safety and design standards have advanced.
We need to upgrade parts of the dam in line with modern requirements and to ensure it can support Melbourne’s growing population and water needs.
This project will ensure we can continue to supply world-class drinking water to our customers across Melbourne, now and into the future.
We are currently doing detailed design work and progressing through planning approvals to ensure construction works can begin on time. Construction is expected to start in 2027 and will take around three years to complete.
We’ll be upgrading key features in and around the dam including:
Under the Water Act 1989, Melbourne Water is responsible for the safety of our dams, including Cardinia Reservoir.
We regularly review the risk associated with all our major water supply reservoirs, so we can prioritise maintenance and upgrade works to meet new engineering standards and practices.
We reduce risks by conducting routine dam surveillance, inspections and detailed risk assessments, as part of our proactive approach to managing dams.
The management of all our dams is in line with the ANCOLD guidelines, which represent the best Australian and international engineering practice in the safe design, management and operation of dams. They provide a consistent framework for assessing risk across all dams and allow Melbourne Water to prioritise safety upgrade works across our portfolio of dams.
In Victoria, the ANCOLD guidelines are further underpinned by state dam safety regulations in Melbourne Water’s Statement of Obligations from the Department of Energy, Environment and Climate Action (DEECA) – the Dam Safety Regulator for Victoria.
The Cardinia Reservoir dam upgrade project is part of our ongoing Dam Upgrade Program to ensure continued compliance with the ANCOLD guidelines into the future. Under this program, we have completed upgrades to the Frankston, Tarago, Toorourrong, Upper Yarra and Greenvale Reservoirs.
The project is in the detailed design stage. Designs are expected to be completed late 2025.
We will also be completing flora and fauna assessments to understand what plants and animals are in the area, how they may be affected, and how they can be managed during the works.
Cultural Heritage Assessments will be undertaken to determine if a Cultural Heritage Management Plan (CHMP) is required.
Works are planned to start in the summer of 2027.
Construction completion late 2029.
Like any major project, there will be some impacts associated with the upgrade works:
Cardinia Reservoir will continue to operate within Melbourne Water’s water supply system throughout the upgrade works.
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The project is being carefully designed to avoid as many trees and shrubs where possible; however, some vegetation will need to be removed so we can undertake the works. We may also need to trim branches where trees are located in close proximity to work areas.
We will work closely with Parks Victoria, DEECA and Cardinia Shire Council to minimise the amount of vegetation that will need to be removed.
All trees to be removed will be identified and assessed by an independent ecologist and qualified arborist. Wherever possible, vegetation material will be mulched or kept for re-use by Parks Victoria in Cardinia Reservoir Park and/or as habitat.
After the works have been completed, disturbed areas will be restored in accordance with revegetation and reinstatement plans approved by Parks Victoria, DEECA and Cardinia Shire Council.
Cardinia Reservoir is Melbourne Water’s second largest reservoir after Thomson Dam, and has an approximate total storage volume of 287 GL.
It was constructed between 1970 and 1973 to secure water supply for Melbourne’s southern and south-eastern suburbs. As an off-stream storage reservoir, it has no effective catchment of its own and receives water transferred from Silvan Reservoir and the Victorian Desalination Plant. Water is also transferred from Cardinia Reservoir to most parts of Melbourne depending on how our supply system is managed.
The reservoir consists of:
The saddle dams are small dams relative to the main dam and are constructed across a low point (saddle) in the natural ridge line of the reservoir perimeter. Their purpose is to allow a higher water elevation and storage.
The main embankment of Cardinia Reservoir is 86 metres high and approximately 1.5 kilometres long. The four saddle dams vary in height from 5 to 16 metres, and in length from 240 metres to 1.2 kilometres.