The Victorian government's $4.9 billion water plan might not be enough to secure Melbourne's long-term water needs, a senior water bureaucrat says. Melbourne Water chairwoman Cheryl Batagol said the forthcoming desalination plant, the controversial northsouth pipeline and other projects may need to be supplemented by other schemes within a decade, Fairfax newspapers reported on Thursday.

"Victoria is undertaking major water augmentation projects, but it remains in the back of my mind, that it may not be enough," Ms Batagol said.

Current rainfall and climate change estimates based on the best estimates of current rainfall and latest climate change information suggest the desal plant and pipeline should secure enough water for the city for the next 50 years, but Ms Batagol said, "none of us can predict the future, it is the unknown.

"We will review the central region strategy again in 2012, and that gives us time to say, 'Here's our augmentation, let's have a look again, where are we and do we need to go again?'." The next big-ticket water project should be a water recycling scheme, but not for drinking, she said. Water Minister Tim Holding has said the existing projects would secure Melbourne's water long-term, but that population growth was an unknown.

"It's a solution for decades to come, not for 10 or 20 years, but for 50 years-plus. It's always hard for people to say this will solve the problem forever because our population is growing much faster than we thought it was even just a few years ago," he said in April.

(The Age, 23/10/2008)