Canberra's frugal water usage equivalent to 1970s when city half the size

 canberratimes.com.au  9/17/2017 2:03:50 PM 

Canberra is using the same amount of water as the 1970s, despite the city's population doubling in the past 40 years.

Icon Water figures show that in 2016-17 the average water consumption per person per day in the capital was 304 litres - about 40 per cent less than before the millennium drought.

The highest total water consumption a year was 77,261 megalitres in 1990-91.

In comparison, in 2016-17 total water consumption had dropped to 49,801 ML.

In the 1990s, each person used an average of about 500 litres a day. By 2016-17 that had dropped to 300litres a person, Icon Water's senior demand and analytics professional, Timothy Purves, said.

"Since 2008 our water consumption has been very steady, with an average water consumption of roughly 300 litres per person per day, or almost 110 kilolitres per capita per year," Mr Purves said.

The savageness of the millennium drought seared into Canberra's psyche the need to conserve water.

And with a dry start to the year, Canberrans continued their frugal water use.

A wet August has eased pressure on Canberrans' parched greenery after a run of dry months.

However, before that, Canberra had experienced the driest June on record, and the driest June–July period since 1982.

Canberra Airport recorded only 2.4mm of rain in June – just six per cent of the monthly average.

The result was in stark contrast to June 2016, which was the wettest June on record.

The dry continued into July, with only 17mm of rain recorded at Canberra Airport – about 41 per cent of the monthly average.

Rainfall was generally above average in Canberra during autumn.

There were 31 rain days at Canberra Airport, above the autumn average of 23 days and the most autumn rain days since 1989.

However, Canberra also recorded the driest summer since 2002-03, with rainfall 45 per cent below average.

While Bureau of Meteorology head of climate monitoring Dr Karl Braganza said rainfall had been low and dam levels dropping this year, he did not predict a return to drought in the near future.

"The outlook is pretty dry looking over the short-term, the odds of receiving above average rain are less than 40 per cent," Dr Braganza said.

"There's nothing out there, like warming ocean temperatures, favouring heavy rainfall.

"Despite low rainfall, ... we're not predicting the onset of another millennium drought type period."

Dr Braganza said soil moisture was low across eastern Victoria, most of NSW, and some of South Australia.

"Even with good rain predicted run-off is lower than would be so there'll be lower flows [into catchments]."

But Icon Water said storage levels meant Canberra's water security was solid.

Icon Water is currently storing almost 228 billion litres or 81.9 per cent of total water storage capacity.

The figure is a drop from 90.3 per cent at the same time last year, and down from 100 per cent in October.

But the reduction is no cause for concern, as Icon Water said it was typical for water storage levels to decline over summer and autumn, and generally increase again in spring.

Historically, Canberra seldom records 100 per cent capacity; other previous occasions include September 2012 and November 1998.

At full capacity, Canberra's four dams – Cotter, Bendora, Corin and Googong – hold 278 billion litres, or more than half the water in Sydney Harbour.

Icon Water said Canberra's water supply system had to be designed to withstand multi-year droughts without the need to enforce high-level water restrictions for extended periods.

Mr Purves said there was no prospect of a shortage in the foreseeable future.

"Currently our dams are storing more water than we could have held at capacity prior to the construction of the enlarged Cotter Dam," he said.

"This is still a lot of water in comparison to our lowest water storage level at 64 billion litres or 31 per cent water storage in the Millennium Drought."

Mr Purves said 2017 had been a relatively dry year to date, so water runoff from catchments into dams had been lower than this time last year.

"The current volume of water in storage is equivalent to about four and a half years' total Canberra and Queanbeyan consumption."

The Canberra region is also in the grip of a dry stretch, with Braidwood weather guru Roger Hosking reporting the country hamlet shouldn't expect a break until at least December.

"In terms of long term, I really don't expect a technical break until December, it's a rugged guess but that the gut feeling and that's what I think," Mr Hosking said.

"Statistically, it doesn't say we won't get rain, but the rain will gradually only improve, no big down pours in the next couple of months. When I say downpour I mean 100mm."

Mr Hosking said the greatest concern was for water storage, as longer dry stretches meant less run-off to fill dams.

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