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We’re planning to complete a dam safety upgrade to Cardinia Reservoir in the summer of 2024/25, as part of our proactive management of our water supply reservoirs. The upgrade will protect and prolong the life of one of Victoria’s most pristine water catchments, helping us to continue supplying world-class drinking water to Melburnians.

Cardinia Reservoir will continue to operate within Melbourne Water’s water supply system throughout the upgrade works.

Why this is important

Cardinia Reservoir was constructed between 1970 and 1973 to the best standards of the day. As dam design standards have improved over the years, the proposed upgrade will ensure Cardinia Reservoir complies with best practice dam safety management standards in line with our Statement of Obligations and the Australian National Committee on Large Dams (ANCOLD) guidelines.

Dam safety regulations

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, and Greenvale Reservoirs, and upgrade works are almost complete at Upper Yarra Reservoir.

What’s happening and when

These dates may be subject to change as the planning and design stage progresses and as more information becomes available.

Started
 

Early planning and design

The project is in the early planning and design stage, which is anticipated to be completed in 2023.

Site investigations

We have already undertaken preliminary investigations to identify what works are required to ensure the dam upgrade is most effective and efficient. Further information about ground conditions, cultural heritage, and plants and animals in the immediate area is required to help inform the detailed design.

Geotechnical investigations are required, which involve drilling multiple boreholes and excavation of test pits along the dam embankments. Initial geotechnical investigations were completed in December 2020, April 2021 and May 2021. Further geotechnical investigations will be undertaken from Tuesday 26 April to Sunday 24 July 2022.

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.

Not Started
 

Works commence

Works are planned to start in the summer of 2024/25 and are expected to be complete in mid-2025.

What to expect

Like any major project, there will be some impacts associated with the upgrade works:

  • Closure of Cardinia Reservoir Park for the duration of the works. Public safety is our number one priority – the closure is necessary to ensure the safety of the community and our workers.
  • Heavy vehicle movements and construction traffic along Wellington Road and other local roads for access to the site.
  • Trimming and removal of some vegetation.
  • Reinstatement of local roads and other areas in Cardinia Reservoir Park that may be affected by our works.

Cardinia Reservoir will continue to operate within Melbourne Water’s water supply system throughout the upgrade works.

View live updates on our water storages

Vegetation removal

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.

About Cardinia Reservoir

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:

  • a main embankment
  • four saddle dams
  • a diversion drainage system comprising a number of embankment dams and inlet structures for transfers from Silvan Reservoir and the Victorian Desalination Plant
  • an outlet tower, pipework and valves
  • a spillway chute.

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.

View Cardinia Reservoir rainfall data

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