VICTORIAN Premier John Brumby turned the tap on the controversial north-south pipeline last week, prompting an avalanche of criticism from the Victorian Opposition and landholders along its route.

As reported in The Weekly Times last week, water began flowing from the 70km, $750 million pipeline last Wednesday.

The pipe will deliver up to 70,000 megalitres per year to Sugarloaf Reservoir.

Mr Brumby said the pipeline was biggest single boost to Melbourne's water supplies since the Thomson Dam was built more than 25 years ago.

But the Opposition accused Mr Brumby of "pretending to turn on the north-south pipeline pumps in a media stunt".

Opposition rural water spokesman Peter Walsh said the pipeline stunt had been orchestrated to avoid the growing furore over the Office of Police Integrity's case against former deputy police commissioner Noel Ashby.

"I have been advised that at Killingworth, where the pipeline draws water from the Goulburn River, the pumps were not switched on," Mr Walsh said.