Table 1 shows that there is a surplus of available water assets over water liabilities and future water commitments that are expected to be settled within 12 months of the reporting date.
|Total water assets as at 30 June 2012||241,667|
|Less water assets not available to be accessed, taken or delivered within 12 months of the reporting date|
|Lakes and wetlands 1||34,622|
|Less total water liabilities as at 30 June 2012||0|
|Less future water commitments expected to be settled within 12 months of the reporting date|
|Expected diversion of surface water allocations (urban water system)||41,790|
|Surplus / (deficit) of available water assets over water liabilities and future water commitments expected to be settled within 12 months of the reporting date||163,366|
Only an estimate of the diversion of surface water allocation has been included as a future commitment expected to be settled within 12 months. It is assumed that this will similar to the volume reported under line item 17.12 Entitled diversion of allocated surface water to urban water system in the 2012 Account.
Based on average historical data, future inflows to the storages used for urban water supply are likely to be between 60,000 ML and 411,000 ML. On an average year, inflow to the reservoirs is 206,000 ML. Of this inflow, only a limited amount is available to ACTEW Water for delivery for urban use. Water is also required to maintain environmental flows along the Queanbeyan, Upper Murrumbidgee and Cotter rivers. Evaporation from the connected surface water store has not been included in this table.
The enlargement of the Cotter Dam will play a key role in helping secure the water supply for the Australian Capital Territory (ACT) and surrounding region in the future, allowing it to deal with frequent, longer and more severe droughts without having to endure high-level water restrictions for extended periods. The new dam will have a capacity of 78 GL, nearly 20 times its current size, and the new reservoir will increase the ACT's water storage capacity by 35%.
The Cotter Dam project received the endorsement of the ACT Government in 2007. Construction of the dam commenced in November 2009, and it is scheduled for completion in 2013.
The Murrumbidgee to Googong Water Transfer involves the transfer of up to a maximum of 100 ML of water per day from the Murrumbidgee River through a 12-kilometre underground pipeline to Burra Creek in NSW. The water then flows approximately 13 kilometres along Burra Creek into Googong Reservoir. The amount of water that can be transferred each day will depend on the availability of water in the Murrumbidgee River, maintenance of the Murrumbidgee River environmental flows and the available storage capacity in Googong Reservoir. Construction commenced in early 2011 and was completed in August 2012.
Contingent water assets and water liabilities
In 2009 the ACT Government endorsed the implementation of the Tantangara Transfer Project. The project is intended to provide the ACT with increased water security in droughts and the flexibility of access to established water trading markets within New South Wales (NSW).
The Tantangara Transfer option involves transferring water from the regulated Murrumbidgee River (below Burrinjuck and Blowering dams) to the ACT via the Snowy Mountains Scheme. The following steps are required:
- buying NSW water entitlements from Murrumbidgee regulated River licence holders downstream of the ACT
- negotiating a long term, secure and flexible commercial agreement with Snowy Hydro Limited for the release of water from Tantangara Reservoir
- establishing interstate trading arrangements between the NSW and ACT governments to allow for transfer of water from NSW to the ACT via the Tantangara Reservoir and return transfers if unused
- delivering water to the ACT via the unregulated Murrumbidgee River above the ACT
- extracting water from the Murrumbidgee River via the Murrumbidgee to the Googong Water Transfer pipeline at Angle crossing
- Storage of the water in Googong Dam until used, and
- Trade of purchased water back to NSW if not used.
ACTEW Water expects the operational requirements of the project to be in place so that the Tantangara Transfer can be used from 2012–13 onwards, as required. The Tantangara Transfers project is continuing. ACTEW Water have purchased 4.145 GL of high security and 12.523 GL of general security NSW water entitlements, and is currently carrying out a project implementation plan which will address all the issues with operating the Tantangara Transfer. This includes the following components:
- Institutional & regulatory framework
- Water division operational planning
- Actew Water corporate/divisional management integration
- Water market & critical management predictive modelling
- Upper Murrumbidgee hydrodynamic modelling
- Stream gauging & water quality monitoring
- Statutory evaluation, reporting & commitment monitoring
- Community engagement & stakeholder management
- Upper Murrumbidgee catchment management improvement
- Water utility reference group
- External reviews & audits
- Risk management
- Project delivery & administration.
Operation of the Tantangara Transfer is contingent on the completion of the Murrumbidgee to Googong Water Transfer project and appropriate arrangements between the ACT and NSW. Given that the required steps for the Tantangara Transfer to become operational are outside the control of ACTEW Water, this is considered a contingent water asset.