4 January 2012
2011 a record wet for city’s dams
- Highest annual catchment rainfall since 1975
- Runoff well above average
- Dams gained 237 billion litres
Melbourne’s dams experienced their wettest year in 2011 in more than three decades, helping storages increase by 13% of capacity.
Storages started the year at 53.7% full and finished at 66.8%. The 237-billion litre gain is the equivalent of 8 months’ water supply for Melbourne.
The major catchments received 1,365mm of rain, which is the highest annual total since joint records for dams began in 1975 and 28% above the long-term average. As a result the amount of streamflow into the dams (634 billion litres) was the highest since 1996 and 29% above average.
Most of the storage increase was made at the system’s largest dam, the Thomson, which gained 198 billion litres - more than 80% of the total storage increase.
General Manager of Asset Planning, Paul Pretto, said the increase in the Thomson’s level was the highlight of the strong 2011 result.
"Storages started 2011 with many of the smaller dams full or close to full thanks to a wet 2010, so it was clear that the Thomson would be the key to the recovery continuing," said Dr Pretto.
"Thomson Reservoir was in the path of much of the 2011 rain and it was able to keep filling while Melbourne was supplied by the other nine dams in the system.
"The Thomson is our drought reserve, designed to be built up in wet years and drawn down in dry times, so it was great to see it recovering from the below average inflow over the past decade and building Melbourne’s water security," he added.
Dr Pretto said the relatively wet end to 2011 was a bonus because it kept storages increasing at a time when they would typically begin a six-month decline.
"The challenge now is for the community to continue their water-saving efforts to help storages stay around 60% as the weather warms up throughout summer," he said.
"Melburnians continued to do a fantastic job of lowering their water use in 2011, despite restrictions easing at the end of spring."
Melbourne’s total water consumption across all uses in 2011 was down 0.6%, or 6 million litres a day lower than 2010.
Stage 1 water restrictions are currently in place.
See the fact sheet (PDF, 52kb) for more information.
Media Contact: Jess Wurf (03) 9235 1587; 0427 171 274
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