ACTEW's recommended water security plan
August 10, 2007
ACTEW has completed its review of the ACT region's water resources and has submitted four key water security recommendations to the ACT Government.
The outcomes of the detailed examination of water supply options include four key recommendations that combined would take three to four years to implement.
ACTEW considers that the key challenge is to build water supply assets that can cope with much reduced average inflows and more frequent, longer and drier droughts, without having to impose high level water restrictions for extended periods.
Therefore, there is a need for supply capacity that is in addition to that needed in normal years. ACTEW considers the financial cost of this extra capacity neither wasted nor premature investment, but essential and justified on the grounds of ensuring water security.
The recommendations are to:
1. immediately commence the detailed planning and construction of an enlarged Cotter Dam from its current capacity of 4 gigalitres (GL) to 78 GL (approx $145M. Capital costs);
2. add to the current capacity to extract water from the Murrumbidgee River by working towards constructing pumping capacity near Angle Crossing for transfer to the Googong Reservoir (approx $70M). This project could also be used to transfer additional flows released from Tantangara Dam if such flows become available.
3. obtain additional water from a source not largely dependent on rainfall within ACT catchments through either:
a. the Tantangara Transfer option (approx $38M); or
b. the Water Purification Scheme (approx $181-274M).
4. assess how any additional energy used may be offset through measures such as carbon offsets (such as planting of trees) or renewable energy capacity.
Included with the recommendations is a report on the outcomes of the community consultation conducted on Water2WATER, ACTEW's proposal in early 2007 that investigated purifying Canberra's used water and adding it to an enlarged Cotter Dam.
"˜If implemented, these projects will provide the ACT and region with the capability to deal with longer, drier and more frequent droughts than that of 2001 to 2006, without having to impose high level water restrictions," said ACTEW Managing Director Michael Costello.
Although the final decision on water prices lies with the Independent Competition and Regulatory
Commission, ACTEW expects that an average annual ACT household water bill would increase by approximately $150 - $280 if all the recommended options were implemented, or individually:
· $70 for enlarging the Cotter Dam;
· $30 for Angle Crossing; and
· $50 for the Tantangera Transfer, or, between $100 and $180 for a Water Purification Plant depending on size.
The water supply review was prompted by extremely low inflows and declining dam levels in the ACT region, and built on the Future Water Options studies ACTEW undertook in 2004-05.
"The ACT region has experienced severe drought conditions over the last six years - and last year alone, inflows into our dams were down by almost 90%. This major change related to a key assumption on climate change and variability prompted us to review and reconsider our existing water supply options, as well as new alternatives such as the Water Purification Scheme," said ACTEW Managing Director Michael Costello.
The proposal is contingent on ACTEW's continued rights to the Googong Dam and its waters. ACTEW and the ACT Government are working with the Australian Government to formalise arrangements that have been operating successfully since ACT self government in 1988.
You can access ACTEW's water security reports and fact sheets on the recommended options here.