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Melbourne's water
storages are currently at:
41.9%
breakdown by reservoir
(you can click on each reservoir
for more information)
Thomson: 27.2%
Cardinia: 43.4%
Upper Yarra: 69.9%
Sugarloaf: 84.1%
Silvan: 88.9%
Tarago: 60.5%
Yan Yean: 54.6%
Greenvale: 66.6%
Maroondah: 100.0%
O'Shannassy: 100.0%
drought and climate change
We have been experiencing a severe drought over the last 12 years. This has impacted on the environment and on our water storages.
On this page:
What is drought?
Land in drought
Drought is a long, unusually dry period when there is not enough water to meet our needs. It may include lower than expected water levels in our reservoirs. It may also include higher than expected demand for water because of hot weather.
A drought may last a few months or many years. The current drought is now in its 12th year.
The impact of a drought depends on the amount of water in our reservoirs (collected from rainfall in earlier years). In early 2008, after 12 years of below average flows into our reservoirs, our water storage levels fell to below 40%.
Farms and market gardens are often the first to be hit by drought, but eventually everybody feels the impact. Drought causes environmental and economic damage. Vegetation is lost, due to a lack of water. The ground becomes very dry and exposed, making it easy for soil to erode into our rivers and creeks. There is an increased risk of bushfires and dust storms, as well as crop and stock losses.
What causes drought?
The main cause of drought in Australia is El Niño. The central and eastern parts of the Pacific Ocean warms up, leading to a major change in weather patterns across the Pacific. The Pacific trade winds are not as strong, and so there is less rain over the eastern and northern parts of Australia. This affects the water supply catchments in the eastern part of Australia.
The 1982/83 Ash Wednesday bushfires happened in drought conditions caused by the El Niño effect. There was a strong El Niño event in 1997/98. However, it did not affect Australia a great deal. The most recent El Niño events were in 2002/03 and in 2006/07, both of which resulted in severe drought.
La Niña is the reverse of the El Niño effect. The central and eastern parts of the Pacific Ocean become cooler. The Pacific trade winds strengthen and the sea to the north of Australia warms up. When a La Niña event is happening, there is a greater chance of rain especially in the eastern and northern parts of Australia.
The last lengthy La Niña event occurred from 1998 to 2001. The Bureau of Meteorology, in June 2007, indicated that a weak La Niña event has been strengthening.
How do we manage drought today?
Over the last century, governments reacted to droughts by building new reservoirs. Today, we recognise this is not a sustainable approach.
Water restrictions were designed to help reduce use and to conserve water. It has been used since the 1960s, but was formalised in 1975, after the 1972/73 drought. The eight-stage set of restrictions was later simplified to the four-stage set in place today.
Melbourne Water regards drought as a normal part of managing our changing climate. We work together with the metropolitan retail water businesses to help Melbournians understand the need to conserve water and reduce our water use.
Permanent water saving rules were introduced across Victoria in 2005. This was in addition to the four stages of water restrictions set in 1995.
Stage 3 water restrictions are in place now in Melbourne.
There is a long-term plan for future water supplies, set by the Government. The plan includes other water sources, such as recycling and desalination.
The impacts of climate change
Climate change refers to changes in the climate. These changes occur naturally over time and can be influenced by human activities.
Our activities - burning fossil fuels, clearing forests and using manufactured gases such as chloroflourocarbons (CFCs) - have contributed to the warming of Earth.
In 2003 we commissioned the CSIRO to conduct a study into the likely impacts of climate change on Melbourne's water, sewerage and drainage systems.
The study, titled Implications of Potential Climate Change for Melbourne's Water Resources, was released in 2005. It identified the following patterns:
- Higher average and summer temperatures
- Less rainfall
- More hot days
- More dry days
- When it storms, it will be more intense
It is clear that climate change will have a long-term impact on our water supplies.