1.4 Lakes and wetlands
This line item represents the volume of water held in lakes and wetlands connected to the surface water store within the Canberra region. The total volume held on 30 June 2012 is recorded as 34,622 ML.
These lakes are used primarily for recreation, conservation and aesthetic purposes, and are not formally associated with the urban water supply system; however, water can be abstracted or released to maintain environmental flows and for small-scale irrigation.
Specific details of lakes are provided in the following table. The volume provided is a sum of the volumes held in the lakes in the Canberra region. The water level at Lake Burley Griffin on 30 June 2012 was about 0.5 m lower than full supply level due to repair work required at the Scrivener Dam.
|Storage name|| Full supply level
|Volume at full supply level (ML)||Water level of 30 June 2012 (mAHD)||Storage volume of 30 June 2012 (ML)|
Lake Ginninderra and Lake Tuggeranong: The Australian Capital Territory (ACT) Government, Environmental and Sustainable Development Directorate (ESDD), Hydstra database maintained by Ecowise Australia Pty Ltd.
No storage volume was available for the most of lakes or wetlands within the Canberra region; however, the capacity of these lakes and wetlands is known. Water levels of Lake Ginninderra and Lake Tuggeranong on 30 June 2012 were above the full supply level and their volume were estimated as the volume at full supply level. NCA provided the water level and volume of Lake Burley Griffin.
Assumptions, limitations, caveats and approximations
- Water levels in Lake Ginninderra and Lake Tuggeranong are generally managed within 200 mm of full supply level throughout the year. Therefore, the estimated storage volumes of these lakes are considered to be only slightly overestimated.
- At present, abstraction from Lake Ginninderra and Lake Tuggeranong is limited to volumes that would have negligible effect on the volume of the lakes (<50 ML).
- The capacity of Lake Burley Griffin is based on survey data collected at the time of construction and fill in 1964.
The uncertainty estimate was not quantified.