Sustainability Report 2006/07Overview
Management of Melbourne’s water supply system was dominated by worsening drought conditions and increasing scientific and community awareness of the potential impacts of climate change.
Total water storages dropped throughout the year from 47.9% on 1 July 2006 to a minimum of 28.4% before recovering slightly and rising to 30.7% by 30 June 2007.
Streamflows into reservoirs during winter 2006 were the lowest on record while during the spring and summer months, catchment rainfall was almost 40% below the 30-year average and streamflows into Melbourne's four major harvesting storages were about 80% below average.
The seriousness of this situation led to the introduction from 1 September 2006 of Stage 1 water restrictions, on top of the permanent water saving restrictions introduced in March that year, moving through to Stage 3A from 1 April 2007.
In October 2006, the Victorian Government established a long-term framework for managing Melbourne’s water resources through the Central Region Sustainable Water Strategy. The strategy, the result of 18 months consultation with stakeholders, including industry, councils and water authorities, outlined actions to provide for Melbourne’s and the surrounding region’s water supply while improving the health of our rivers and meeting the challenges of climate change and population growth.
Actions in the strategy were based on two possible scenarios – the observed streamflow since 1913 adjusted for potential gradual climate change, and the other based on a sudden climate shift assuming similar conditions to those observed in the past 10 years.
In light of the worsening drought, this year the Government announced The Next Stage of the Government’s Water Plan, building on the water saving campaign it initiated in Our Water Our Future in 2004.
The $4.9 billion plan will provide up to 240,000 million litres per year of new water for Melbourne over the next five years, which is half of Melbourne’s annual demand. Melbourne Water will be a key player in the delivery of the plan, which brings forward some of the proposed actions from the Central Region Sustainable Water Strategy, as well as introducing new ones in response to the lowest streamflows in Victoria’s history.
The plan involves:
- Constructing a $3.1 billion desalination plant near Wonthaggi to provide an extra 150,000 million litres of water a year, with the potential to further upgrade the capacity to produce 200,000 million litres if required
- Major infrastructure upgrades in the Goulburn irrigation region to achieve water savings in the lead-up to the connection of a pipeline to Sugarloaf Reservoir to provide an extra 75,000 million litres of water a year for Melbourne, as well as similar volumes for irrigators and the environment
- Expanding the Victorian water grid through pipelines connecting the desalination plant, Goulburn Valley area and Geelong to the Melbourne supply system
- Completing the upgrade to the Eastern Treatment Plant by 2012 to provide Class A recycled water, and the further investigation of the feasibility of providing recycled water for power generation in the LaTrobe Valley as well as for a range of other industrial uses and potential to substitute for environmental flows in the lower Yarra River
- Reconnecting Tarago Reservoir to Melbourne’s water supply system in 2009.
Melbourne Water is continuing to work closely with councils, community and environment groups, and local landholders to finalise the planning and works required to reconnect Tarago Reservoir back into Melbourne’s water supply system.
Prior to reconnection, a water treatment plant needs to be constructed to treat the water that will be supplied to Melbourne from the reservoir. Melbourne Water has now acquired the land and completed the functional design of the treatment plant.