Melbourne
1.1 Storages

The volume presented in the water accounting statements (686,630 ML) represents the volume of water held in surface water storages in the Melbourne region at the end of the 2011–12 year.

The volume presented is the sum of the volume held in water storages that have a total storage capacity over 1,000 ML, including the volume of dead storage. The following table presents a breakdown of individual storages in the Melbourne Region.

Water storages

Storage operator	Storage	Total storage capacity (ML)	Dead storage (ML)	Storage volume at 30 June 2011 (ML)	Storage volume at 30 June 2012 (ML)
Melbourne Water	Cardinia Reservoir	288,964	2,053	206,406	219,792
	Greenvale Reservoir	27,501	662	21,382	21,618
	Maroondah Reservoir	28,233	6,054	28,393	28,474
	O'Shannassy Reservoir	3,123	n/a	3,235	3,208
	Silvan Reservoir	40,581	136	34,674	36,447
	Sugarloaf Reservoir	99,222	2,969	98,552	96,835
	Tarago Reservoir	37,580	n/a	24,000	22,434
	Upper Yarra Reservoir	204,985	4,406	142,602	14,8319
	Yan Yean Reservoir	33,125	2,859	30,229	30,307
Southern Rural Water	Melton Reservoir	14,360	140	13,577	13,992
	Merrimu Reservoir	32,215	335	23,889	25,158
	Pykes Creek Reservoir	22,119	1,770	28,092	21,637
	Rosslynne Reservoir	25,400	150	16,716	18,409
Total		857,408	21,534	671,747	686,630

Thomson Reservoir is not included in the storages as it is located outside of the Melbourne region boundary.

Australian Water Resources Information System (AWRIS)—Water storages.

Bureau of Meteorology.

Storage volume was measured at the start and end of the reporting period by using gauged water level height(s) in metres, Australian height datum (mAHD) for individual storages. The height measurement was converted to a volume using the storage-volume curve(s) provided by the managing authority.

Storage capacity was calculated using the full supply level (FSL), and converting it to a volume using the storage volume curve(s) provided by the managing authority.

• 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.

• Storage capacity may differ from those published on the Water storages page of the Southern Rural Water website due to rounding and uncertainty in the true values.

The volume was estimated from measured data.

In the 2011 Account, the volume of water in surface water storages was compiled from two data sources:

• The storage volumes for Melbourne Water managed storages were obtained from the water storages product (see Quantification approach).
• The storage volumes for Southern Rural Water managed storages were obtained directly from Southern Rural Water.

Following publication of the 2011 Account, Southern Rural Water provided storage data to the water storages product for the 2011 year and these volumes have been retrospectively updated in the 2012 Account. The difference in the values published in the 2011 account compared to the 2012 Account may be due to the updated values sent by Southern Rural Water.

Consequently, the volume has been restated from 669,642 ML (as published in the 2011 Account) to 671,747 ML as shown in the following table.

Comparative year information for line item 1.1 Storages

Storage operator	Storage	2012 Account volume at 30 June 2011 (ML)	2011 Account volume  at 30 June 2011 (ML)
Melbourne Water	Cardinia Reservoir	206,406	206,406
	Greenvale Reservoir	21,382	21,382
	Maroondah Reservoir	28,393	28,393
	O'Shannassy Reservoir	3,235	3,235
	Silvan Reservoir	34,674	34,674
	Sugarloaf Reservoir	98,552	98,552
	Tarago Reservoir	24,000	24,000
	Upper Yarra Reservoir	142,602	142,602
	Yan Yean Reservoir	30,229	30,229
Southern Rural Water	Melton Reservoir	13,577	13,577
	Merrimu Reservoir	23,889	27,757
	Pykes Creek Reservoir	28,092	22,119
	Rosslynne Reservoir	16,716	16,716
Total		671,747	669,642