Victoria's controversial desalination plant has been relying on generator power for several weeks, with electricity shut off due to a problem with cabling.
Two cable joints were found to be performing below specification and needed to be repaired, plant spokesman John Ridley said.
Electricity to the Wonthaggi plant has been shut off while the repairs take place.
"Because the plant is not producing any water, it is of no consequence and the systems to maintain the plant have all been supplied by the standby generators which are there for that reason," Mr Ridley told AAP.
"Once the cable is fully operational again, which will be very soon, days rather than weeks as I understand it, then everything will be absolutely fine."
Electricity is needed to run pumps to maintain the plant, he said.
The cause of the cabling problem is being investigated.
The $6.1 billion desalination plant, which provides a drought-proof water supply to Melbourne and Geelong, was built under the previous Labor government and had massive cost blowouts.
It began operating in 2012 but the government has placed a zero-gigalitre order for the past two financial years.
A decision on a 2014/15 order is due by April.