Murray-Darling Basin
1.4 Lakes and wetlands

The volumetric value for the line item for the 2010–11 year was 1,907,353 ML.

This line item represents the volume of water held in lakes and wetlands that are connected either seasonally or perennially to the river channel system. Specific details of individual lakes and wetlands, and the totals for each region are provided in the following table. For other lakes and wetlands in the Murray–Darling Basin (MDB) the volumetric values were not available.

Water from lakes and wetlands listed for the line item is not used primarily to supply water for licensed entitlements. Line item 1.1 Storages includes storages that are used to supply water for licensed entitlements.

 

Details of lakes and wetlands in the MDB region

Water resource plan area	Sustainable diversion limit area		State	Lake name	Total capacity1 (ML)	Total storage1 volume on 30 June 2011
	Code	Name				(ML)	(%)
SA Murray	SS11	SA Murray	SA	Lake Albert	279,583	273,937	98
			SA	Lake Alexandrina	1,644,884	1,594,916	97
ACT	SS1	ACT	ACT	Lake Burley Griffin	33,000	33,000	100
			ACT	Lake Ginninderra	3,700	3,700	100
			ACT	Lake Tuggeranong	1,800	1,800	100
Southern Basin					1,962,967	1,907,353	97
Whole MDB region					1,962,967	1,907,353	97

¹Dead storage volumes are included

 

Lakes Burley Griffin, Ginninderra and Tuggeranong are used primarily for recreation, conservation and aesthetic purposes, and are not formally associated with the urban water supply system. However, water from these lakes can be abstracted or released to maintain environmental flows and for small-scale irrigation.

At present, abstraction from Lake Ginninderra and Lake Tuggeranong is limited to volumes that would have negligible effect on the volume of the lakes (less than 50 ML).

 

(1) Lake Albert and Lake Alexandrina: Bureau of Meteorology (the Bureau)'s Water Storages, Australian Water Resources Information System (AWRIS), and (2) Lakes Burley Griffin, Ginninderra and Tuggeranong: ACT Government Department of Environment, Climate Change, Energy and Water's Hydstra database, maintained by Ecowise Australia Pty Ltd.

Lake Albert and Lake Alexandrina: the Bureau, and Lakes Burley Griffin, Ginninderra and Tuggeranong: ACT Government Department of Environment, Climate Change, Energy and Water.

Lake Albert and Lake Alexandrina

Storage volume was estimated at the start and end of the year by using gauged water level height(s) (metres Australian Height Datum) for individual storages. The height measurement was converted to a volume using the storage-volume curve(s) of the storage.

Lakes Burley Griffin, Ginninderra and Tuggeranong

No storage volume or level information was available for these lakes. However, their capacity is known. Therefore, the total storage within these lakes was estimated based on the assumption that these water bodies were full at the start and end of the year.

Lake Albert and Lake Alexandrina

Storage-volume curves represent specifically surveyed parts of the water storage and may not reflect the storage-volume relationship across the entire storage.

Water storages are subject to sedimentation and other physical changes over time, which in turn affect the accuracy of the storage-volume curves.

Lakes Burley Griffin, Ginninderra and Tuggeranong

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 in the water account are considered to be only slightly overestimated.

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.

This line item corresponds to line item 1.4 Lakes and wetlands – connected, reported in the 2010 Account. In the 2011 Account, the following change was made that caused the 2009–10 year value to be restated:

•  The scope of the line item was changed as an additional storage was added for the 2011 Account compared to the 2010 Account, in order to provide more complete information to the users of the National Water Account.

The changes and their respective values are detailed in the following table.

 

Restatement of comparative year information made for the line item 1.4 Lakes and wetlands

2010 Account line items	Segment	Volume at 30 June 2010 reported in the 2010 Account (ML)	Difference due to scope change(ML)	Volume at 30 June 2010 reported in the 2011 Account (ML)
1.4 Lakes and wetlands – connected	Northern Basin	–	–	–
	Southern Basin	1,130,947	38,500	1,169,447
	Whole region	1,130,947	38,500	1,169,447

 

Lakes Burley Griffin, Ginninderra and Tuggeranong were not included in the 2010 Account. Scope change was due to including volumes for these lakes to the comparative year.