Mr Cowper said the utility sent letters to his constituents indicating water charge categories in Pinjarra had changed and could result in increases of 31 per cent from July 1.
‘Their spokespeople were unable to explain the changes and blamed the Economic Regulation Authority for the new categories and charge settings,” he said.
‘Further probing confirmed the new categories and charges were based on infrastructure costs, despite the fact that 60 per cent of Perth’s water comes from this area.
‘Does this mean the cost of infrastructure such as that installed at Ravenswood last year to shandy water from dams in our region with desal water from Binningup and to pump it to Perth is being charged to our account?’ he asked.
A Water Corporation spokesman said Pinjarra had not been singled out.
The spokesman said the cost to supply water to all towns and schemes across WA was reviewed every three years, taking into account the operating cost and capital cost changes for the water supply scheme.
Where the cost changed significantly, the town or scheme moved to a new class each year.
The specific reason for the pricing change in Pinjarra was to reflect recent investment in its water supply scheme, including new desalination plants.
Pinjarra had also experienced significant growth with more than 250 new services connected in the past three years, requiring additional capital and operating expenditure, identifying Pinjarra as a Class 2 town, the spokesman said.