Canberra: Future outlook
This section looks forward 12 months and considers what water assets, claims, and commitments might affect the region's water resources.
Future prospects
Table N27 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.
| Volume ML | |
| Total water assets as at 30 June 2015 | 266,085 |
| less water assets not available to be accessed, taken, or delivered within 12 months of the reporting date: | |
| dead storage | (5,060) |
| lakes and wetlands1 | (39,223) |
| less total water liabilities as at 30 June 2015 | 0 |
| Subtotal | 221,802 |
| less future water commitments expected to be settled within 12 months of the reporting date: | |
| expected diversion of surface water allocations (urban water system) | (47,115) |
| Surplus / deficit of available water assets over water liabilities and future water commitments expected to be settled within 12 months of the reporting date | 174,687 |
1 Some water stored in the lakes and wetlands in the Canberra region can in fact be accessed. Data on the dead storage component of these storages were not available for the 2015 Account and as such the entire volume has been reported as water that is not available to be accessed, taken, or delivered.
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 Allocated diversion: surface water to urban water system in the 2015 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 Icon 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.
For more detailed information about future water and climate predictions, including seasonal streamflow forecasts and short video summaries, please see Climate outlooks on the Bureau of Meteorology website.
Enlarged Cotter Dam
The enlargement of the Cotter Dam in 2013 has played a key role in helping secure the water supply for the ACT and surrounding region in the future, allowing the region to deal with frequent, longer, and more severe droughts without having to endure high-level water restrictions for extended periods. The reservoir has a total capacity of 79,374 ML and it increased the region's water storage capacity by 35%. As of 30 June 2015, the volume of water in Cotter Reservoir was 67,069 ML, approximately 84% of its storage capacity.
Murrumbidgee to Googong water transfer
Construction of the Murrumbidgee to Googong water transfer commenced in early 2011 and was completed in August 2012. It enables the transfer of up to 100 ML of water per day from the Murrumbidgee River through a 12-kilometre underground pipeline to Burra Creek in NSW from where it flows approximately a further 13 kilometres into the Googong Reservoir. It has not yet been operated except for maintenance purposes, but 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.
Contingent water assets and contingent water liabilities
Contingent water assets
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 NSW.
The Tantangara Transfer Project 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:
- purchase NSW water entitlements from Murrumbidgee regulated river licence holders downstream of the ACT
- negotiate a long-term, secure, and flexible commercial agreement with Snowy Hydro Limited for the release of water from Tantangara Reservoir
- establish an intergovernmental agreement between the NSW and ACT Governments to allow for the transfer of water from NSW to the ACT via the Tantangara Reservoir and for the return of transfers if unused
- deliver water to the ACT via the unregulated Murrumbidgee River above the ACT
- extract water from the Murrumbidgee River via the Murrumbidgee to Googong water transfer pipeline at Angle Crossing
- enable storage of the water in Googong Reservoir until used
- enable trade of purchased water back to NSW if not used.
The Tantangara Transfer Project agreements were completed during the 2013–14 year to enable the delivery of water if required. Some details regarding the obligations of ACT and NSW governments are still to be finalised but these are not essential for Icon Water to access the water. Present high storages mean that it will be some time before a Tantangara Transfer is required.
The Tantangara Transfer Project is continuing. Icon Water holds 9,549 ML of high-security NSW water entitlements. These water entitlements are from the NSW regulated Murrumbidgee River and are to be utilised under the Tantangara Transfer Project. This option is to be available for use only during extreme droughts.
The Tantangara Transfer Project implementation plan will address all the issues with operating the transfer. This includes the following components:
- institutional and regulatory framework
- water division operational planning
- Icon Water corporate/divisional management integration
- water market and critical management predictive modelling
- upper Murrumbidgee hydrodynamic modelling
- stream gauging and water quality monitoring
- statutory evaluation, reporting and commitment monitoring
- community engagement and stakeholder management
- upper Murrumbidgee catchment management improvement
- water utility reference group
- external reviews and audits
- risk management
- project delivery and administration.
The Tantangara Transfer is considered a contingent water asset and is subject to appropriate arrangements between the ACT and NSW governments.
Contingent water liabilities
There are no contingent water liabilities in the Canberra region.