Water storage levels

Daily water storage levels (as at 8 am each day) are added to the page between 2 pm to 3 pm on weekdays, and 4 pm to 5 pm on weekends and public holidays. See how this data is calculated. Note: the graph below is indicative and not to scale.

Know more about Melbourne's 10 water storage reservoirs, or click on a reservoir listed below to find out more. To calculate water storages, we measure the water storage levels of our reservoirs over a 24-hour period (8 am - 8 am) every day. The data is then verified at the end of each week. We use this data to make sure that all our reservoir users – such as environment agencies, other water authorities and retailers – get access to the water they need. Sometimes this involves moving water from one reservoir to another. Note that water from the Victorian Desalination Plant is contributing to our water storages. The 2020-21 water order of 125 gigalitres from the Victorian Desalination Plant commenced on July 1. For an overview of the daily amount contributed to our water storages over the past 30 days, see our desalination data. For more on how desalination contributes to securing our water supply, view our desalination page.

We’ve been collecting water storage data since 1940. We update this data at the end of every month. This data informs our long-term planning. Select multiple years to see how water storage levels have changed over the years or view 'all years'. Note: Full system storage volume has changed in the past. The current volume (1,812 GL) has applied since July 2010.

We record rainfall over a 24-hour period (8am-8am) at four of our water catchment areas. Water catchment areas include the land surrounding our reservoirs. The monthly average (ML) is based on the average from previous years. This rainfall data has been verified. If you need to see the latest numbers, the rainfall and river level app has unverified data.

We monitor the amount of water that flows into our four major reservoirs, including river, stream and rainfall run-off. We record daily flow into water storages over a 24-hour period (8am-8am). The weekly and monthly average (ML) is based on the average from previous years.

We monitor Melbourne’s daily water usage to ensure we continue to supply water for the growing population. This includes household and business usage, as well as Western Water’s non-metropolitan water supply. We record Melbourne’s total daily water use over a 24-hour period (8am-8am). The daily average (ML) is the five-year average for the month. Each week we update the daily average per person and compare it with the previous week.