Vic desal water order faces backlash

Victorian Premier Daniel Andrews is expected to face tough questioning over his decision to order desalinated water to back up the state's water resources when parliament resumes on Tuesday.

Mr Andrews will order 50 gigalitres of water from the controversial Wonthaggi Desalination Plant because of low rainfall and dry conditions.

The government says the order, which is expected to add $12 a year to the average metropolitan water bill, will help water storages in Melbourne, Ballarat and Geelong next summer.

The premier has already faced a strong backlash over the decision, with both the Nationals and Greens accusing him of ordering based on political gain rather than the water needs of the state.

Victorians pay $1.8 million a day for the plant whether water is produced or not.

A PricewaterhouseCoopers report found a 50 gigalitre order would cost an extra $637 million on top of that figure.