The average Canberran uses 276 litres of water every day, far more than they would be able to collect on an average Canberra block, according to ACTEW Water.

It equates to almost 150 large bottles of soft drink but is a 10th less than the 315 litres a day each of us used five years ago.

Doctoral scholar Walter Reinhardt said improvement will come with a catch.

"There's still time to reduce consumption, but at what cost?" he said.

"It's very costly to install rainwater tanks on everyone's house and politically costly to tell people to have shorter showers."

South east Queenslanders lowered their use to about 140 litres a day during the drought and it has not risen much since.

It is, however, in a part of Australia boasting more rainfall than Canberra.

Germany is one of the best water users in the developed world because its residents use an average of 80 litres a day.

"They don't water their gardens as much as we do," he said, pointing out that European-style yards in Australia dotted with hedges and thirsty plants were an easy way to waste water.

The 28-year-old Mr Reinhardt identifies a new enemy in the war to lower water use in Canberra.

Air conditioners using evaporated water have become a popular but un-water wise way to get through summer.

Evaporative coolers can use about half a litre of water a minute.

Restrictions are unlikely to be reintroduced in the short term.

ACTEW Water spokesman Chris Hare said his organisation was of this opinion because of the work being done to guarantee a bigger water supply.

Piping up to 100 megalitres a day from the Murrumbidgee River to the Googong Dam as well as enlarging the Cotter Dam have better guarded the territory against water shortages.