In Australia we are in the middle of a particularly bad drought, in Melbourne the dams supplying drinking water capacity are down to approximately 38% and falling between 0.5-1% a week. Without rain in the near future we conceivable will be without drinking water this time next year. Our households, like many others, have been living under water restrictions for about 7 years, in Sydney and now in Melbourne, which basically limits outside water usage. But still the issue remains one of the biggest social issues we face as a nation!
Add into the mix that the WWF recently released an updated list of the world top 10 rivers at risk, Australia’s Murray-Darling river system made the list. This is significant as the area around the Murray-Darling river system provides around 40% of our food, and 70% our irrigation. Without the river system one could only speculate that our food prices would rise dramatically and our importation of food would increase. In 2007 we have seen a massive reduction in the inflows into the system, prompting the government to restrict irrigation.
Unless there are very substantial early, inflows there will be insufficient water available to allow any allocation at the commencement of the 2007-08 water year for irrigation, the environment or any purpose other than critical domestic supplies.
The irony, if you would call it, is based on the WWF Living Planet Report 2006 Australia is only using 5% of our available fresh water as we are unable at this stage to capitalise on all of our fresh water.
Over the last few weeks a few of us in the office have been talking about water usage, what we are doing, and not doing. We are all limiting shower length, stopped watering gardens or are using grey water from washing machines, leavng our cars dirty etc.
There are two areas we wanted some more information, how much water “should” we be using and how much water do our appliances use. This weekend I sat down to try and find out.
Good Water Usage
According to the a brochure from City of Melbourne on calculating water usage using less than 1,200 litres of water per week per person is great, 750 litres is exceptional.
I pulled out our water bills and for the last few years our household has been using about 600 litres per person per week, which is fantastic based on the report. In 2002 and 2003 we were using about 1,500 litres each every week so it does seem that we have made some adjustments in our lifestyle.
But is it enough?
I went looking to find a reference on what is sustainable water usage, although I feel I had limited success. In the UK a report indicates at least a 20% reduction in water usage across domestic and industry from a baseline of 150-180 litres per day. This is supported by figures from The International Food Policy Research Institute in a report Global Water Outlook to 2025, published in September 2002. From the factsheet we see that in 1995 the average daily demand for water in developed countries was 131 litres, rising to 149 litres by 2025. A report from ACT Council of Social Services also references a 20% reduction in domestic water usage.
What reports don’t state is are these figures direct domestic usage or have they been adjusted to include water used as part of food and consumable production?
Taking these number let’s assume a 20% reduction in our domestic water usage is sustainable. Using the Melbourne City recommendations of good water usage is 1200 litre per person per week (171 litres per day) and the UK report’s base line of 150-180 litres. I assume we need to reduce our average water usage to 120 litres to be sustainable.
Our family is using about 90 litres per person per day, which based on the above is sustainable! Woohoo. But if we need a 20% reduction we would need to reduce our domestic consumption to 70 litres per person per day. Which would be difficult without a major change in how we live our life.
The second part of our discussion in the office was how much water is used by our appliances. We have an Asko W640 front loader washing machine which uses between 53-56 litres per cycle depending on our settings. We are averaging 4-5 loads a week so at the top end 280 litres per week.
Our dishwasher is new and based on the manual uses 19 litres for a regular load or 24 litre for a heavy load. We run the dishwasher everyday with about 5 regular loads and 2 heavy or about 143 litres every week.