MELBOURNE Water has turned on the Goulburn River pumps.
It plans to bring another eight gigalitres down the north-south pipeline in coming weeks as it eases the city's water restrictions.
A Melbourne Water spokesman said the pipeline was helping raise Melbourne's storage levels from record lows.
"It's the kind of certainty and security you need in a city of four million people," he said.
But opponents of the pipeline say Melbourne does not need the water, given a surge in inflows.
As of Monday, Melbourne's water storages held 712 gigalitres. The Goulburn storages of Eildon and Waranga held almost 1700 gigalitres, while the main Murray storages of Dartmouth and Hume held 2800 gigalitres.
Plug the Pipe spokeswoman Jan Beer said Melbourne should have left the 75 gigalitres it intends to take from the Goulburn in Eildon dam.
"Why are they (Melbourne Water) pumping out of the Goulburn River when they have two dams that could be filling Sugarloaf, instead," she said.
Ms Beer said both the Maroondah and O'Shannassy Dams were full and spilling water back down the Yarra River and out to sea.
"They could be putting that water into Sugarloaf, instead of down the Yarra."
Since August last year, Melbourne Water has pumped almost 19.5 gigalitres down the north-south pipeline via the Goulburn River, with another 7.5 gigalitres ready to be pumped from Eildon Dam.
Another 10 gigalitres from Lake Eildon's water quality reserve is due to become available within weeks, with another 37 gigalitres of water savings from the $1 billion Northern Victorian Irrigation Renewal Project to be made available in September.
By the end of September, Melbourne Water will have gained access to 74 gigalitres.
Green power company AGL started releasing part of its 80 gigalitre hydro-electric entitlement from Eildon this month.
