Annual Water Planning Assumptions Review 2006 Report

ACTEW has completed its Future Water Options 2006 Annual Review of Planning Variables for Water Supply and Demand Assessment and provided the report to the ACT Government. This report is part of ACTEW's commitment to continue prudent planning for a secure water supply for the ACT and region.

The Future Water Options studies undertaken by ACTEW in 2004-2005 identified six key planning variables that underlie predictions of Canberra's water supply security. They are:

• climate variability and climate change,
• impact of bushfires on inflows to ACT reservoirs,
• future population growth in Canberra and Queanbeyan and the possibility of servicing additional areas,
• reduction targets in per capita water use set by the ACT Government in Think Water, Act Water,
• environmental flow requirements,
• acceptable levels for the duration, frequency and severity of water restrictions during times of drought.

This report looks at changes to the assumptions that have occurred since the Future Water Options work in 2004 and early 2005. ACTEW engaged ActewAGL to undertake this assessment.

The conclusions of the report are:

• The assumptions have not changed over the last twelve months with respect to climate change and variability; and bushfire impacts, in such a way as to change the judgements made in Future Water Options and subsequent advice. A recent change in the Gudgenby hydrology has been noted and may have implications on the long term viability of a Tennent Dam if it persists. ACTEW will continue to monitor this issue carefully.
• Minor changes have been identified for trends in water demand reduction targets and population projections and with the new 2006 environmental flow guidelines. However, these are short term changes and cause little impact on the predicted timing for the next water source. Water supply modelling from July 2006 will take these changes into account.
• Further work has been identified and initiated with respect to reviewing system performance criteria (time in restrictions) particularly with respect to the new Permanent Water Conservation Measures, a proposed new water restrictions scheme and the operating rules applied to the system. This will be a major focus in the 2007 review, in addition to identifying any new trends with the other assumptions.

In summary the report concludes that there has not been any significant changes to the variables to change the recommendations put forward to Government since April 2005.

Download a PDF copy of the Annual Water Planning Assumptions Review 2006 Report