22 June 2006

Polar caps are vanishing, sea levels are rising, flooding is more frequent and severe, migratory animal patterns and cycles are affected, food chains are affected, human health is affected; rainfall is reduced and evaporation increased. Scientists and politicians agree that global warming is a reality.

This year the Water Managers’ Forum at the IPWEA (NSW Division) Annual Conference 22-23 May 2006 focussed on Global Warming and its implications for water managers in New South Wales.

Facilitated by Will Strachan, General Manager, Sustainable Water Solutions, Department of Commerce, the Forum was a very interesting discussion providing a range of perspectives on Global Warming.

Audience participation was invited and the major points of the proceedings were recorded.

Scientific Perspective: Prof Andy Pitman, Macquarie University

Accepted scientfic theories include:

• Greenhouse gases are rising due to human activities
• Temperature has increased around the globe on average by 1º C since 1990
• The planet is warming up and warming faster each year.
• Global warming caused the heatwave in Europe in 2003 which was responsible for 30,000 deaths

Less certain scientific theories include:

• Rainfall is changing more dramatically than previously
• Global warming is changing rainfall patterns
• Evaporative demand is changing the physical structure of the ground

Best case scenario for global warming has the planet warming by 1.4º C on average over the next 100 years. Dangerous warming is considered to be above 2º C and the worst case is an increase of 5.8º C. An average increase of 3.4º C is expected.

Legal Perspective: Andrew Petersen, Team Leader - Environment, PricewaterhouseCoopers Legal

The lack of a national framework to address environmental issues is a problem that is increasingly apparent. However, most legal practitioners accept that there is going to have to be change in the way that the issues are examined.

In 2005, Andrew attended the United Nations Global Warming Conference in Montreal , Canada and was one of 10,000 delegates to participate in discussions on emerging issues directly related to global warming.

Over the past 10 years most of the principles of environmentally sustainable design (ESD) have been accepted into a legal framework. A recent court case, Telstra vs Hornsby City Council is an example of the acceptance of ESD as a legitimate concern for the to the courts.

In addition, a national debate on the price of water needs to happen soon.

Local government perspective: Gary Mitchell, Executive Officer, Water Directorate

Over the past five years, lower than average rainfall has been recorded across NSW. In addition, 2005 was the hottest year ever recorded in Australia with 2006 expected to also be very hot. From December 05 to April 06, the Department of Primary Industry’s drought affected ratings for NSW have steadily climbed from 18.5% to 45.8%.

Consequences of increased temperatures for water operators:

• Increased variability in weather, water cycle and stream flow
• Extreme weather patterns
• Reduced environmental flows
• Reduced water quality
• Increased evaporation
• Increased consumption
• Decreased rainfall
• Contaminated groundwater
• Droughts/Floods
• Rising sea levels
• Increase runoff
• Heatwaves
• Increased snow melt
• Increased aquatic weeds and Blue-Green Algae
• Increased erosion and sedimentation

For water managers and operators the consequences of global warming are that the management of water infrastructure and catchments is going to become more complex, more unpredictable and more costly. This plus water quantity and quality issues will inevitably lead to a rise in the cost of water. The community is going to need to be educated about this cost increase. Adaptation will be necessary and solutions will include reduced demand, reduced water loss, increased reuse and changed standards. In addition, water managers are going to need to diversify their supply of water to avoid a crisis.

Central Coast perspective: Clr Robert Bell, Gosford City Council

On the Central Coast there has not been decent rainfall for almost 14 years. As a result, Gosford City Council implemented a range of demand management strategies in the early to mid 1990s. These strategies have resulted in a decline in average individual usage of water from 235kl/year to 179kl/year.

The Central Coast needs to diversify its water supply and is considering a range of options. Currently, a pipeline between the Central Coast and Hunter region is being constructed to bring an additional 20Ml/day. The pipeline will be operational by the end of 2006. In addition, a desalination plant that can generate 20Ml/day is also being considered.

There is some evidence to suggest that a 40-50 year cycle in the weather is to be expected. Anecdotal evidence is that wetter years are getting wetter with drier years being drier.

Feedback from the community is very clear: it wants answers from the Council not options and it wants the solutions to be enacted quickly.

In conclusion

Will Strachan thanked all the panellists and delegates for their contributions to the discussion. He advised that the OzWater Conference in Sydney in 2007 will be seeking to address the differences between the city and bush experiences with global warming.

It is going to be very important for water managers to consider carefully what types of climatic events they are vulnerable to and what will impact most on their local communities.

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