FutureWe'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 Park and access roads will be closed throughout construction for public safety.
Why this is important
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.
What’s happening and when
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:
- Raising sections of the dam walls
- Improving seepage monitoring and collection
- Upgrading the filters inside the dam walls
- Installing new security fencing along the main dam
- Upgrading to access tracks
- Park improvements.
Our responsibility
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 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.
Managing our impacts
We are taking steps and working alongside important stakeholders to manage the impacts of this project, including native vegetation removal.
We are currently planting around 40 hectares of native vegetation around other areas of the Reservoir Park, and 5 hectares of carbon forest.
We will work alongside VicRoads to understand access road closure's effects on traffic and possible diversions.
Once works are complete, we will reinstate the park and work with the local community, Parks Victoria and Cardinia Shire Council to ensure that the Reservoir Park can be well used and celebrated for years to come.
EPBC referral
We have prepared a referral to the Federal Government under the Environmental Protection and Biodiversity Conservation (EPBC) Act, to determine how we assess and mitigate the impacts of native vegetation removal, including to flora and fauna.
Keeping you informed
We will keep the local community, neighbours and other key stakeholders informed through a range of communication and engagement methods. These include park signage, newsletters, notifications, social media updates, in-person information sessions and more. We'll continue to share information as the project progresses, including details, timing of specific activities as they become available.
Drop in information sessions
We will be at the Reservoir Park to share project information and answer questions.
- Saturday 14 March, 10am to 2pm
- Sunday 15 March, 10am to 2pm
Detailed design
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.
Construction works start. Reservoir park and access roads closed.
Works are planned to start in the summer of 2027.
2029 Construction finishes
2030 Reservoir Park reopens
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 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.
