Friday, September 23, 2005
The dry continent gets thirsty

Continuing drought has forced Brisbane City Council to implement Level 2 water restrictions. Residents will still be able to water their gardens, but only using a hand held hose, between the hours of 7pm and 7am on alternate days. Cars can only be washed with buckets, swimming pools can only be filled during garden watering times and hosing concrete driveways – presumably in the hope they will grow – is banned.

Brisbane’s principal water sources, the Wivenhoe and Somerset dams are now at 37% capacity. If summer rains are as poor as the last 5 years, we’re in trouble.

Wivenhoe’s capacity is some 1.16 million megalitres and Somerset’s is 380,000. To gain some perspective, at full capacity, with zero inflow, Wivenhoe and Somerset could supply Brisbane for 2,655 days at average use. Currently, we have 980 days left.

Medium term policy responses have focused on water supply management. As the population grew, more dam storage capacity was identified and implemented. The only demand management measures considered were short term – as part of periodic dry spell water restrictions. But even these have not been particularly onerous.

Australians have developed a close affinity with water. They are moving to live close to it in their droves and pay top dollar for a home by the sea, or the next best thing – a home adjacent to a tidal canal development. Celebrity demographer Benard Salt has dubbed this the third Australian culture shift, after the bush and the suburb.

And they use it profligately too. Australians are not only the highest global per capita emitters of CO2, but they are also right up there in per capita consumption of reticulated water.

It would funny, if it were not tragic: Australians live on the driest continent on the planet, yet have backyards as lush green as the European gardens on which they were modelled, thanks to nearly half of our drinking water being thrown onto the grass.

Therefore, half of all the infrastructure spending to get fresh water from Wivenhoe to Brisbane – approximately 80km – is spent on servicing resident’s thirsty gardens and swimming pools.

Policy makers are only now beginning to get to grips with the challenges to growth that their dehydrated continent imposes on them. In South East Queensland, the population is projected to rise by 1 million people over the next 20 years. The State Government has recently stated its goal is to accommodate this increase with no overall rise in reticulated demand. Queenslanders will have to invest in water harvesting and change their attitudes to water supply to meet this challenge. There is little alternative as few appropriate dam sites remain.

This challenge does not require inventing something new. As with many more ecologically sustainable practices, it is more a case of relearning lessons from the past.

Our current domestic water paradigm can be summed up by ‘single use, down the sewer’. We flush our toilets with water good enough to drink. Aboriginal Australians must despair at our foolishness. Plumbing systems must be adapted to accommodate multiple uses for the water coming onto each property or community. We need fully integrated systems, where only the poorest quality water - for which no further use can be found - enters the sewage system. Not only would this improve water efficiency, but it would also delay the need to expand sewage treatment systems, thus capturing even greater social benefits.

A parallel strategy must involve rainwater harvesting. Cath and Kim’s penchant for low density living generates swathes of suburban rooftops from which rain drains straight into our creek systems. Rainwater tanks were commonplace just 20 years ago, but now they are the exception, rather than the rule. But only recently have Councils been provided the mandate to require all (Class 1) new dwellings to install water tanks.

These water tanks will also improve flood mitigation and the health of our waterways by slowing run off. It is no irony that local flooding is an issue in times of drought, it is a direct result of poor policy.

But integrated domestic water management systems, which include provision for rainwater harvesting are long term measures which will only begin to reduce growth in demand when sufficient new housing stock has been built. It is unrealistic to expect to see significant retrofitting of integrated systems into existing dwellings and often more expensive to do so, when compared to business as usual.

Therefore, medium term measures are essential to curbing ballooning demand. A more responsive water pricing system is critical. This would provide rewards to those who use water wisely and penalise those who expect a swimming pool’s worth of drinking water should be provided as a right.

However, cultural barriers prevent water from becoming a simple commodity, to be traded like concert tickets or crude oil. But this can be overcome be blending such market mechanisms with more socialistic interpretations of water access.

Each resident could be assigned a quota of water to be consumed over a year. Those who under utilise their quota could trade with those who wish to overuse. Either way, each ‘citizen’ is guaranteed a fixed proportion of the total supply at a fixed price and each has an incentive to benefit from efficient use of water and/or investment in domestic water saving devices. Larger households would be protected from burgeoning domestic bills as the quota is assigned per person, rather than per property.

Using modelling at a fixed price, based on today’s price of water, supplied from BCC, my own household would save $68 per annum on our current bill based on such a tradeable quota system. Furthermore, Brisbane’s heaviest users might be further encouraged to reduce their consumption when faced with stumping up an additional $28.60 per person per year. Under the current billing regime, our efficient use gives us less benefit.

Water usage against billing for Brisbane and 17 Day Road

	Standing charge	Kilolitres use pa	Billing usage at 85c per kl	Total price	Proportional use	Proportional billing
Brisbane average for Class 1 dwelling	$105	283	$241	$346	100%	100%
17 Day Rd (Class 1 dwelling)	$105	141	$120	$225	50%	65%

Financial model based on tradeable quota system per person

	Standing charge	Kilolitres use pa	Proportional use	Total bill (baseline)	Proportional billing	Billing based on baseline and usage	Benefit
High Brisbane use	$26.25	192	211%	$189.28	183%	$217.85	-$28.60
SEQ target (2015)	$26.25	91	100%	$103.25	100%	$103.25	$0.00
17 Day Road occupant	$26.25	35	38%	$56.25	56%	$39.23	+$17.02

Meanwhile, across agriculture and industry, a revolution in water efficiency is required. But there is evidence that a change is in the air. The Great Artesian Basin stores ancient ground water trapped deep under 1.7 million square kilometres of Australia’s Eastern interior and contains an estimated maximum of 900m megalitres. For many years unregulated bores drew on this water to irrigate the dry interior. Water surplus to agricultural requirements simply drained away to evaporate into the atmosphere. Since boring operations began, in the middle of the 19th century, the rate of extraction has been higher then replenishment and bore pressure has been dropping. Only now, following a program of regulating flow and more water efficient irrigation systems is equilibrium being reached again. But still you must question why we insist on growing two of the most water intensive agricultural products – cotton and grain fed cattle – in the middle of the desert.

Again, some progress is being made on the large masterplanned community at Springfield, south west of Brisbane. Homes have been installed with dual-reticulated systems, using rainwater and recycled grey water toilets and gardens. However, this scheme applies to just 14 homes, out of an (already) 10,000.

Inertia and poor crop planning should eventually give way to good policy. But until then, Queenslanders would be wise to start treating their water as preciously as their petrol.

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