The State Opposition Leader Eric Ripper says Western Australians are set to be hit with steep increases in water prices for the third year in a row.

Mr Ripper says the government's budget estimate papers show water prices are set to rise by more than eight per cent next year.

He says the hike will mean water prices will have increased by more than 40 per cent, or $160 a year for the average household in three years.

"Of course in a dry climate there is pressure on water prices and I think extravagant users of water should pay the price, but water is also a basic utility for every family and there should be protection for that basic amount of water that everyone needs to use," he said.

The Minister for Water Resources, Graham Jacobs has been contacted for comment.