Strong run-off and average September rainfall has seen Melbourne’s water storage pass 80 per cent capacity for the first time in 15 years.


Storages started September at 76.8% and finished the month at 80.2% full. The 3.4% gain was slightly above the average September increase (2.6%).


Melbourne Water attributes the higher than average gains to consecutive wet months, allowing for large quantities of run-off water to enter the dam system. This meant that the September rain was more easily converted into runoff into the major reservoirs, which received 104 billion litres of streamflow (22.7% above the long-term average).


General Manager of Asset Planning, Paul Pretto, said September was typically one of the most productive months for storages, and this year was no exception.


"Storages typically continue to increase throughout spring, and our focus will remain on banking as much water in storages before the warmer, drier summer months,” said Dr Pretto.


“Dam levels tend to start to decrease in December and continue to draw down for up to six months due to less rain, hotter weather and higher water use, so it’s important that we build reserves now,” he added.