Drought Management
The current 11-year drought has severely reduced the amount of water flowing in Melbourne's rivers and creeks and the level of water stored in our water supply reservoirs.
This ongoing drought affects everyone and demands a co-ordinated approach.
We're working with the retail water companies to help people and businesses understand the need to further conserve water and reduce demand.
Drought Response Plan
Melbourne Water and the retail water companies have developed a Drought Response Plan.
The plan co-ordinates management of the water supply system to minimise drought impacts. Actions of the plan include water restrictions and permanent water saving rules.
To view a copy of the plan, go to your local retail water company - City West Water, South East Water or Yarra Valley Water.
Melbourne Water and the retail water companies are putting in place a number of drought contingencies to secure our water supply during this time of unprecedented low inflows to our reservoirs.
What is drought?
Drought is a prolonged, abnormally dry period when there is not enough water to meet normal or expected needs. It may include lower than expected water storage volumes and flows to reservoirs, and higher than expected demand for water caused by hot weather.
Drought may last a few months or many years.
We regard drought as a normal part of climate variability that must be managed.
Impact of drought
Farms and agriculture are often the first to be hit by drought, but eventually everybody feels the impact.
It causes environmental and economic damage, often resulting in loss of vegetation and soil erosion, reduced water quality, and increased risk of bushfires and dust storms, as well as crop and stock losses.
The level of impact depends on the amount of water in storage (from rainfall in previous years). After 11 years of below average stream flow, storage levels at the end of 2008 have fallen to below 35 per cent of capacity.
History of drought in Melbourne
Over the last century, the approach to managing drought was to build new reservoirs to meet increasing demand for water. Today, the Government and Melbourne Water recognise this approach is no longer sustainable.
Managing water demand during drought has also involved water restrictions designed to curb use and conserve water storages. Since the 1960s, water restrictions have been introduced in dry years because of low stream flow into water storage reservoirs resulting in low storage levels.
Water restrictions were formalised in 1975 following the 1972-73 drought, however the eight-stage set of restrictions introduced at the time was later simplified. In 1995, drought response plans were completed for the newly formed metropolitan retail water companies including a four-stage restriction regime.
El Niño and La Niña
The main cause of drought in Australia is El Niño - the extensive warming of the central and eastern Pacific Ocean that leads to a major shift in weather patterns across the Pacific.
The 1982/83 Ash Wednesday bushfires were largely due to drought conditions caused by the El Niño effect. The most recent strong El Niño event was 1997/98, with smaller events happening in 2002-2003, 2004-2005 and 2006-2007.
The El Niño phenomenon affects runoff in catchments serving all major water supply systems in eastern Australia.
La Niña, the reverse of the El Niño effect, relates to changes in atmospheric conditions and ocean circulation. In Australia, especially the eastern part of Australia, La Niña events are associated with an increased probability of wetter conditions. The most recent strong La Niña was 1988/89, with a moderate event for about three years at the turn of the century.
