Climate change: coming to a tap near you

Australia’s drinking water may be at risk from climate change. Credit: Cate Grant (ABC News)

AUSTRALIA’S DRINKING WATER SUPPLIES may be at risk from threats from left field, according to two recent scientific reports. Climate change is implicated in both of them. It’s evidence, as if we needed any more, that the consequences of climate change may be entirely unexpected.

Groundwater – water trapped in rocks and tapped by bores – supplies vast amounts of Australian agriculture. But in some places, Perth for example, it supplies the drinking water too. In a recent AM report, Dr Adrian Werner from Flinders University in South Australia, expressed concern that underground drinking water supplies near the coast could be rendered unusable by rising sea levels.

“If you take water out of the aquifer, the higher density of the sea water forces it into the aquifer and the high salinity of the sea water means the aquifer – or at least those wells – are no longer usable,” he said.

“I think as Australia’s population continues to increase especially in the coastal zones, as the sea levels rise, and as the climate changes, I think the pressure on coastal aquifers will continue to grow.”

Over at the University of New South Wales, Dr Stuart Khan and colleagues published a report into recent water quality problems and their relation to unexpected weather events.

They found that while a weather calamity can affect drinking water quality, the real problems arose when a combination of weather calamities came fast upon each other’s heels. “[W]ater quality impacts were caused or exacerbated by the occurrence of multiple significant weather events, rather than individual extreme weather events,” they wrote.

It is exactly the conditions that are expected with climate change.

“In the coming 50 years in Australia it is expected that the average temperature will increase with hotter droughts, longer and more intense fire seasons and changes to the frequency and intensity of rainfall patterns.”

In one example, the drought of 2001 to 2007 reduced a dam to 33.6 per cent of its capacity, and a bushfire in 2006 resulted in a build-up of ash in the catchment area. When a rain came along and washed the ash into the partly full dam, and a strong wind stirred the dam water, it created perfect conditions for a blue-green algae outbreak.

This case of drinking water rendered non-potable joined nine others in the study, with combination punches by the weather being the reason water became undrinkable.

Australia spends a vast sum of money each year on creating drinking water. The health and prosperity of our nation rely on the very basic requirement for clean water.

But with suggestions that salt-water intrusion and increased extreme weather events could affect our water supplies, it is clear that our ability to deliver clean water in the future may be compromised.

Engineering could no doubt remedy the situation – desalination is a proven method of securing water supply, traditional water treatment can expunge contaminants from natural supplies – but engineering solutions are expensive.

Tom Mollenkopf chief executive of the Australian Water Association in a submission to a NSW inquiry into the adequacy of its dams said this week:

“As a result of climate uncertainty, it is difficult to comment on the capacity of existing water storages into the future.”

“Climatic events are becoming more extreme, and we need to have infrastructure, technology and skilled people to cope with future conditions… [M]odelling, monitoring and learning processes can build an inherent adaptive capacity within the water industry which will allow new approaches to evolve apace as different climate change effects unfold.”

How much of our taxes would need to be redirected to clean our water? How much would water rates rise? How much new infrastructure would need to be built? Would we have the skills to address the demand for new water infrastructure? Do we have the health services to deal with a rise in giardia or cryptosporidium cases? Will we have enough water for everyone?

These are the kinds of questions governments need to be addressing today, in order to prepare for a future that deals effectively with the challenges presented by climate change.

When something as elementary as clean drinking water for the Australian people is at risk, the full threat of the unexplored consequences of climate change suddenly becomes real.

Author: Sara Phillips
Source: ABC Environment



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