Perth the capital of Western Australia, is not only one of the most isolated cities in the world, it is also becoming one of the driest in Australia.
Since the gold rush of the 1890s, impressive engineering schemes have transported enough water to make Perth a city of lush lawns and eye-catching flowerbeds, to the surprise of some visitors.
But a drop in average annual rainfall in recent years, along with some truly dire climate change projections, have required government and business to focus on water security. Australia’s Climate Council estimates that water flow from rainfall into Perth’s dams has slumped by 80% since the 1970s, with precipitation in the south-west corner of Australia forecast to drop by up to 40% by the end of the century.
Coping with climate change
Last year, Perth’s dams received just 72.4bn litres of water – far less than the 300bn currently demanded by Perth’s two million-strong population. A huge desalination facility, completed in 2006, has helped make up this shortfall, but behavioural and technological change is also bridging the gap.
Western Australia’s Water Corporation, a government agency, works with every business in the state that uses more than 20m litres of water a year to make savings. The Water Efficiency Management plan, introduced as part of a range of mandatory water efficiency measures that apply to all sectors of the community, provides businesses with free training, help in data-gathering, and a certification scheme that allows them to promote themselves as water-conscious companies.
If they don’t meet certain requirements, however, they are at risk of fines and will be ineligible for the recognition scheme. A total of 330 businesses have reportedly saved enough water to fill the equivalent of 20,000 Olympic-sized swimming pools since the Water Corporation started this project in 2007.
Garden City Shopping Centre, for example, has started using acoustic listening equipment to locate pipe leaks, helping to reducing water use by 10%, while the Crown Promenade hotel has cut its water use by 25% by reducing the flow of its taps and installing dual-flush toilets, among other things, according to Water Corporation.
Perth’s largest theme park, Adventure World, checks water levels and pressure using real-time monitoring. If a leak is detected, maintenance to resolve the problem can be quickly deployed. Around 30m litres of water have been saved in the past two years this way.
“When we put a new water attraction in, people are asking questions on social media about how much water we’re using. There’s a lot of scrutiny on us,” says Ross Ogilvie, general manager of operations at Adventure World. “Everyone in Perth is well aware of the need to save water.”
Adventure World has installed two new filters, at A$100,000 (£46,700) a piece, saving 30,000 litres of water a day in peak season. Ogilvie says it will take up to five years for the filters to pay for themselves, but that it’s an easy business decision.
“It’s a corporate social responsibility issue, really. We need to save water,” he says. “Every induction of [new staff members] we have we talk about water efficiency, we ask people to report every leaky tap. I think people have come to accept that now.”
Awareness and action
The years of drought have changed attitudes among Perth’s public, as well as its businesses. Despite a rising population, water consumption has fallen from 191,000 litres to 131,000 litres per capita per year over the past decade in the Australian city. In comparison, for example, San Diego’s consumption is an estimated 249,000 litres per capita per year.
“There is more awareness of the issue. When you compare it to somewhere like San Diego, I’d say Perth is well ahead,” says Professor Anas Ghadouani, regional executive director of the CRC for Water Sensitive Cities. “California seems to be shocked when there is a drought, whereas in Perth people are more aware of where water comes from. There’s a focus on diversity of sources that doesn’t surprise people now. The idea of drinking recycled wastewater is not a crazy idea to Perth people any more.”
The Water Corporation is embracing a technology that also provides drinking water to Disneyland in California: groundwater replenishment. This process, where treated wastewater is pumped into an underground aquifer to be reused as drinking water, has undergone a trial near Perth and is expected to fully roll out next year.
“The advanced water recycling plant can be expanded to produce 28bn litres of water each year when required,” a Water Corporation spokeswoman says. “Groundwater replenishment could supply up to 20% of Perth’s drinking water needs by 2060.”
Such work will only become more urgent as Perth dries further. Climate change will not be kind to the city, nor to the famed Margaret River winemaking region to its south.
“Things are going to get a lot worse for Perth,” says David Karoly, climate scientist at Melbourne University. “They are already seeing the impact of reduced rainfall, and the future will see an additional doubling of the decline they’ve already seen.
“The only way for Perth to continue as a city is to find alternative water sources because a further large decline in rainfall will mean they won’t have enough water to supply their current population.”
Press link for more: Oliver Milman | theguardian.com