# Cardinia Reservoir

Cardinia Reservoir is an Australian man-made water supply saddle dam reservoir. The 287,000 ML (63 billion imp gal; 76 billion US gal) water store is located in Emerald–Clematis–Dewhurst in south-eastern suburbs of Melbourne, Victoria. Construction started in May 1970 and was completed in 1973 at a cost of more than A$11.4 million. The dam that creates the impoundment is called the Cardinia Dam.

## History

As Melbourne's water supplies struggled through the 1960s the need for additional water storage became evident. Cardinia Creek ran from the Dandenong Ranges to Western Port, passing through some small but well-defined hills south of the outer suburb of Emerald. This site was chosen as being suitable for a new reservoir. In 1966, plans for the construction of the Cardinia and Thomson reservoirs were accepted by the Government of Victoria. Construction of the Tarago Reservoir commenced in 1966 and was completed in 1969. This water storage was built by the State Rivers and Water Supply Commission of Victoria (SR&WSC) to improve the capacity of the water supply system to meet the ever increasing demand for water in the district. By 1967, Melbourne struggled through a severe drought and water restrictions were imposed in the summer of 1967–68. As a result, plans for construction of Cardinia and Thomson reservoirs were advanced.
With the construction of one large rolled earthfill and rockfill embankment to serve as the Cardinia Dam wall, and some other saddle dams in nearby hills, the large water storage facility of the Cardinia Reservoir was created. The dam was built by Fluor Construction, and engineered by Snowy Mountains Engineering Corporation, under contract to the Melbourne Metropolitan Board of Works (MMBW). The dam wall height is 86 metres (282 ft) and the main embankment is 1,542 metres (5,059 ft) long. The two saddle dams are 10 metres (33 ft) high and 323 metres (1,060 ft) long; and 16 metres (52 ft) high and 1,219 metres (3,999 ft) long, respectively. At 100% capacity the dam wall was designed to hold back 286,910 ML (63.11 billion imp gal; 75.79 billion US gal) of water. The surface area of Cardinia Reservoir is 1,295 hectares (3,200 acres) and the catchment area is 2,800 hectares (6,900 acres). The ungated uncontrolled spillway is capable of discharging 12 cubic metres per second (420 cu ft/s).
Construction of the dam was completed in 1973, following which it took another four years to fill, including substantial water transfers from Silvan Reservoir. As part of the Victorian Government's policy that fluoride should be added to all public water supplies, construction began on local fluoridation plants. In 1981, following continued demand for potable water on the Mornington Peninsula finally exceeded the district's ability to meet its own water supply needs. Despite upgrading of existing facilities, water from the MMBW reservoir at Cardinia was first used to supplement local water supplies. Export of "Australia Pure", a bottled water from Cardinia Reservoir, commenced in 1993 to several European countries and the United States.
The surrounds of the reservoir were allocated $1 million for landscaping work to create a recreational area including picnic areas, playgrounds, carparks and walking tracks.

## Operations

Cardinia receives water via a pipeline from Silvan Reservoir. A 3.5-megawatt (4,700 hp) hydroelectric power station at the outlet of the pipeline generates electricity as water is transferred to Cardinia. Water from Cardinia supplies Melbourne's southern and south-eastern suburbs, and the Mornington Peninsula.
The Cardinia Reservoir is managed by Melbourne Water.