The Yan Yean Reservoir in Melbourne’s north – the first reservoir built to service Melbourne and surrounds – is celebrating 170 years of operation.
The turning of Yan Yean Reservoir’s first sod took place on 20 December 1853. Prior to this, Melburnians drew their drinking water supply from the Yarra River – a waterway that was also colloquially named ‘Yarra Soup’ thanks to it also being the city’s main drain.
Designed to provide Melbourne with a safe, secure and great tasting water supply, the Yan Yean Reservoir was the largest man-made lake in the world when it was completed and was the first of a series of reservoirs that would eventually service a city of more than 5.3 million people.
170 years on, Melbourne Water now has ten water storage reservoirs that collectively hold over 1,812 billion litres of water, with the Thomson Reservoir (1,068 billion litres) being the largest.
In support, there are 38 smaller service reservoirs spread across Melbourne. Fed by the larger reservoirs, these store one to two days of water to meet local demand.
Melbourne Water Principal Heritage Advisor, Paul Balassone, said, “The reason Melbourne’s water tastes so good comes down to our protected catchments.
“Our forests act as a natural filter, slowly releasing rainwater into our rivers that flow into our reservoirs. They filter the water naturally, so we only need to perfect the water at our water treatment plants. Very little treatment is needed, to be honest.
“Following this, we continually test our water quality to ensure Melburnians are only getting the finest, best tasting water possible,” Mr Balassone said.
While Melbourne’s water supply comes primarily from its reservoirs many are interconnected, enabling Melbourne Water to transfer water between them. The utility can move water to parts of Melbourne that are experiencing higher needs or safeguard water supply in the event of an emergency, like bushfires.
Since it was commissioned in 2012, the Victorian Desalination Project is also used to help bolster supply. Since 2016, more than 450 billion litres of desalinated water have flowed into reservoirs, helping maintain levels and preventing Melbourne from forced water restrictions.
The desalination plant is an example of recent developments to maintain water supply for a city that is expected to double in population by 2050.
As Melbourne’s current water use exceeds natural flows into reservoirs by 50–70 billion litres annually, Melbourne Water said it is working hard to continually update its infrastructure.
One current projects is the development of a new pipeline between the Yan Yean Water Treatment Plant and Bald Hill in Kalkallo. The project is designed to help meet the growing water needs in the northern and western suburbs – an area that continues to grow.
Featured image: An historical photo of Yan Yean Reservoir. Courtesy of Melbourne Water.