A drop in the ocean?
South
Australians have long been aware of their state’s reputation as the
‘driest state in the driest continent’, and with water restrictions
introduced more than a year ago, and a ‘Save the Murray Levy’ now added
to SA Water bills, water conservation finally seems to be finding
prominence on government priority lists and in the public consciousness.
But are these initiatives making a difference or are we just treading
water? Charlotte Knottenbelt reports.
When water restrictions were introduced to SA in June last year, most householders duly complied with the new rules, which include a ban on sprinkler use during the day, among a raft of other measures. While initial indications are that domestic water consumption has decreased – SA Water was processing the figures to work out exactly how effective at the time this article went to print – the question of how far the measures will go toward actually saving the Murray has been raised by environmentalists and householders alike.
While most of us were happy to do our bit to reduce water consumption, we also know that household use accounts for a small proportion of Australia’s overall water usage, with the bulk of water going towards irrigation.
“Irrigators drawing water from the Murray in South Australia presently take six times as much water as all urban users combined,“ says John Argue, an adjunct professor at the Urban Water Resources Centre in UniSA’s School of Natural and Built Environments. “The main aim of reducing the amount of water we take from the Murray is to ensure that Adelaide’s water in the second half of this century has a salinity level meeting the World Health Organization’s ‘top quality’ standards, and to do this, Adelaide must reduce its take by 61 gigalitres, so we still have a long way to go.“
Prof Argue says while dual flush toilets and rainwater tanks have their place in water conservation, nothing short of a major cultural shift is required if we want to see real results.
“Undoubtedly the greatest contribution to water conservation would be achieved if Adelaide’s home garden culture were to change from its present emphasis on exotic species to native or drought tolerant grasses and shrubs,“ he says. “This change could achieve the 40 per cent reduction in demand required to meet the WHO standard.“
The responsibility shouldn’t all be on the householder, according to the director of UniSA’s Water Law and Policy Group Professor Jennifer McKay, who cites the Mawson Lakes development in Adelaide’s north – where a separate ‘grey water’ tap has been fitted to all homes for use in the garden – as exemplary. “We need to see more schemes where non potable water is used to water gardens, but such schemes are hard to retrofit, so there’s a real need for strong legislation to make sure that these types of systems are planned in new homes from the beginning.“
Probably predicting resistance from bottom-line conscious developers and home-buyers, the state government is yet to make water recycling a compulsory part of new house planning, however they have introduced legislation requiring all new homes after 2006 to be fitted with rainwater tanks (following the recommendation of Adelaide Thinker in Residence, Herbert Giradet.)
Prof Argue says that while the legislation is a move in the right direction, the new laws are unlikely to have much effect for decades – by which time the amount of new houses will have cancelled out any savings. “A rainwater tank of acceptable size, plumbed into a household water distribution system can save some 40 to 50 per cent of in-house use per annum, so there’s no doubt that this is a positive action,“ he says.
“However, the rate of new housing is some 8,000 units per annum: given that there are presently over 400,000 residential units in Adelaide, it will be well into the 21st century before the full effect of the initiative will be felt.“
He backs McKay’s call for better urban planning to maximise water conservation, and says UniSA is in many ways leading the field of Water Sensitive Urban Design (WSUD). “UniSA has made a major contribution to WSUD in Australia, particularly in regard to stormwater management, with more than 30 research and community projects around Australia looking at flood control, pollution control and stormwater harvesting,“ says Prof Argue.
UniSA’s Urban Water Resources Centre has also produced a practical manual, WSUD: Basic procedures for ‘source control’ of stormwater – a handbook for Australian practice, to be launched at the Third WSUD Conference to be held in Adelaide this November.
Sensitive urban design is well and good, but the way we manage water in our cities is inextricably linked with water management practices in rural areas, and this is where Professor McKay’s work examining the different water allocation policies and laws – from local councils to state government, federal government and international law – comes in.
McKay, who has recently completed a report looking at the interplay of different laws in relation to Victoria’s water resources, says the different laws are not working effectively together. But while pointing out that existing laws are inconsistent across jurisdictions, Prof McKay notes the difficulty in getting stakeholders to agree to blanket measures.
“There’s a high level of political sensitivity about changing water allocation policies but a recognition of the need to reduce the complexity,“ she says.
“The new National Water Initiative has proposed plans to rationalise the water allocation and water markets across the nation, but Western Australia and Tasmania have not signed up to the initiative because they say it is too Murray-Darling Basin focused,“ she says.
“We need national consistency, but before we can hope to achieve that, we need consistent environmental data on existing water use. At the moment we’re not sure by how much we are salinising or over drawing aquifers.
“We need to set up an environmental reserve for water, and then only allocate to farmers and the urban environment an amount that is sustainable.“
For more information on the Third Water Sensitive Urban Design conference, visit www.plevin.com.au/WSUD2004/