The Water Corporation has defended its quality assurance measures in the face of an increasing number of people unhappy about the quality of their water.
In its annual performance review of water providers, the State's economic watchdog revealed that in the 12 months to June last year, the Water Corporation had been hit with a 21.5 per cent jump in the number of complaints from Perth customers about water quality.
More than 5700 customers raised concerns about "discolouration, taste, odour, stained washing, illness or cloudy water", the Economic Regulation Authority said.
The rise, from about 4600 in the previous 12 months, drove the average number of complaints for all WA towns up by 5.4 per cent.
Water Corporation spokesman Phil Kneebone blamed the increase on a "major" incident in February in the southern Perth suburbs of Como, Bentley, Karawara, Wilson, Manning, Salter Point, Waterford and Bentley. He said the "unfortunate" incident, in which routine maintenance caused drinking water to turn brown, lay behind most of the increase in gripes.
Mr Kneebone insisted it held no implications for the State-owned utility's quality checks, saying the complaints did not concern safety and represented a tiny fraction of the corporation's customer base.
Water Minister Bill Marmion said the rise in complaints could be "solely attributed" to the incident.
He praised the performance of the Water Corporation after the ERA found service-related complaints and the average length of unplanned interruptions both fell.
At the same time, Mr Marmion has admitted the State Government was offering no incentives for householders to install costly greywater recycling systems, despite spruiking the technology as a water-saving tool.
Kevin Beckham, who paid more than $12,000 to install a greywater and rainwater system at his Leederville home last year, said he acted out of environmental obligation.
But he queried why the Government was not offering any money to encourage people to follow suit, saying it suggested "they want to have their cake and eat it as well".