The Melbourne region

Overview of the 2011–12 year

Rainfall across the Melbourne region was generally above average for the 2011–12 year. Although rainfall was above average, these conditions represent a decrease in rainfall compared to the 2010–11 year. The persistence of above average rainfall conditions across Melbourne contributed to increased inflows into surface water storages. The volume of water held in storages increased marginally during the 2011–12 year and, across the region, storage volume was greater than 80% of capacity on 30 June 2012. Closing net water assets in the Melbourne region was 1,443,482 ML, compared to 1,190,898 ML at the end of the 2010–11 year. For more information on the region's water assets, refer to the Water accounting statements.

The urban water supply system sources water for users primarily from surface water. During the 2011–12 year, the volume of surface water diverted for urban supply and the volume supplied to users increased compared to the 2010–11 year. The increased demand on surface water probably reflects the reduced rainfall conditions during the 2011–12 year compared to the 2010–11 year.

The key water account information for the Melbourne region during the 2011–12 year is presented in the following table. Information on the uncertainty associated with the volumes presented in the table is provided in the relevant sections of the account.

 

Key water account information for the Melbourne region during the 2011–12 year


Contextual information: Climate overview
Climate Overview 2011–12 2010–11 Long–term average
(1900–2011)
Rainfall: 1,008 mm Rainfall: 1,210 mm Rainfall: 870 mm
Evapotranspiration: 788 mm Evapotranspiration: 899 mm Evapotranspiration: 646 mm
For more detail on the Melbourne climate refer to Climate overview.

 

Contextual information: Water overview
Water overview Werribee River Maribyrnong River Yarra River Bunyip River
Below average flows Below average flows Above average flows Above average flows
For more detail on streamflow in the Melbourne region refer to Water overview.

 

Water accounting statements
Accounting statements 2011–12 2010–11
Total water assets (as at 30 June) 1,443,482 1,190,898
Total water liabilities (as at 30 June) 0 0
Change in net water assets 252,584 502,540
Closing net water assets 1,443,482 1,190,898
For more detail on water assets and water liabilities refer to Water accounting statements.

 

 

Notes: Water resources and systems

 

Surface water storage
Surface water 30 June 2012 30 June 2011
Total capacity Volume % of capacity Volume % of capacity
857,408 ML 686,630 ML 80% 671,747 ML 78%
For more detail on surface water storage in the Melbourne region refer to Surface water.

 

Water abstractions
Groundwater Total water abstracted
2011–12 2010–11 Recent activity
Surface water: 404,934 ML Surface water: 381,910 ML Water abstraction for private use from surface water and groundwater has increased
Groundwater: 13,173 ML Groundwater: 10,196 ML
For more detail on water abstraction in the Melbourne region refer to Surface water and Groundwater.

 

Urban water supply
Urban water system
Total water supplied  
2011–12 2010–11 Recent activity
356,398 ML 356,079 ML Urban water consumption remained constant
For more detail on the urban water system in the Melbourne region refer to Surface water and Groundwater.