Water groups have labelled an easing of water restrictions in South Australia and Victoria as “political opportunism”, as disquiet grows over the delayed construction and cost blowouts of desalination plants.

Both the Victorian and South Australian state governments declared last week that they would be easing water restrictions, after years of onerous constraints on public consumption.

Respite in Victoria will see restrictions eased back to stage 2 just three months before the state heads to an election, while relief in South Australia comes on the back of growing criticism over construction of an Adelaide desalination plant.

But Dr Ian Douglas, national coordinator of water group Fair Water Use, has told Crikey that the easing of water restrictions is merely an “opportunistic” political ploy to get voters onside, as public opinion continues to turn against desalination plants.

“They’re in panic mode now. It’s basically trying to justify the mess that is the desalination construction,” Douglas told Crikey. “It shows a total lack of understanding of the causes of the water crisis. These have not been unduly high falls that we have had recently.”

Premier John Brumby cited heavy winter rainfall and the upcoming completion of the state’s $5 billion desalination plant as reasons for the respite. Melbourne’s dams are currently sitting at 41%, after sitting at a record low of 25.6% just a year ago.

The announcement by South Australian Premier Mike Rann to ease restrictions was more surprising. Just last week, Water Minister Paul Caica ruled out any relief in South Australia until a desalination plant was online.

“He (Caica) talked about December 1 being for the end of water restrictions and can I just announce today, well, let’s just do it, let’s just do it, I can announce today that water restrictions will be ended on December 1,” Rann told reporters. “(It) is the right time to end water restrictions because that’s when there’s hot weather there is no point in doing it now when it’s raining all the time.”

Ian Douglas said that both the South Australian and Victorian governments were in panic mode and that they were sending “all the wrong messages about wise water use”.

“They’re saying that it’s back to business as usual, when it was business as usual that got us here in the first place,” Douglas told Crikey. “To say that we can remove water restrictions is absolute myopia and stupidity.”

Victoria’s Target 155 program has been credited with saving almost 38 billion litres in the 18 months since its inception. Meanwhile, South Australians have also reduced water consumption, with the government putting their savings at 29 billion litres this year compared with 2002.

Environment Victoria Chief Executive Kelly O’Shannessey agreed with Douglas, telling Crikey that there was a likelihood that an easing of restrictions would see an increase in water use.

“What we’re worried about is that the government have lifted restrictions without providing more incentives to keep on saving water,” O’Shannessey told Crikey. “People have worked really hard to but there is a worry that they will go back to wasting water.”

Correction: The original story said 38 billion litres had been saved by the Victorian government in six years. The figure should have said 18 months. Also, according to the South Australian government, that state has used 29 billion litres of water less this year compared with 2002.