Monthly Water Report August 2010
The Monthly Water Report provides a summary of the status of Victoria's water resources and water supplies at the end of the reporting month. It is based on validated water resource information provided by Victoria's 19 Urban and Rural Water Corporations and the Bureau of Meteorology.
Each month's report is published online the following month. For detailed, specific and up-to-date information, please contact the relevant Water Corporation or the Bureau of Meteorology. Links to these organisations are located within the Monthly Water Report.
Rainfall
Rainfall during August was well above the long-term August average across most of Victoria. Small areas of Gippsland received average rainfall only.
Stream flows
Above average rainfall during August has resulted in significant improvements surface runoff to streams at the end of the month. Of the 28 representative stations, eleven stations recorded flows above the long-term August average. These stations were mainly located in the upper catchments of the Southwest, the Alpine region, and the lower Loddon River.
Storages
The total volume in Victoria’s major storages increased by 11.5% to 51.1% of total capacity during August. The major regional water storages increased by 12.5% to 52.7%. Melbourne's storages are holding 41.3% of capacity, 5.8% higher than at the end of July.
Restrictions on Urban Water Supplies
During August, Central Highlands Water reduced restrictions for Maryborough and district to Stage 3, and Ballarat and district to Stage 1. Wannon Water removed restrictions for Hamilton, Cavendish, Tarrington and Dunkeld.
At the end of August, 239 Victorian towns were on restrictions, which is significantly lower than the same time last year when 332 towns were on restrictions.
Irrigation Allocations
G-MW announced allocations against high-reliability water shares (HRWS) for all northern systems during August. This is the first time all systems have had a non-zero allocation at the beginning of the irrigation season since 2005/06. The allocations announced on the Bullarook, Campaspe, and Loddon systems were also the highest allocations on these systems since 2005/06.
G-MW updated its seasonal allocation outlook for the 2010/11 season on 16 August. Under average conditions, the allocation on the Goulburn and Murray systems would be 56% and 73% by 15 October.
Coliban Water will announce the 2010/11 allocation for the Coliban Rural System on 15 September. However, as a minimum, a 30% emergency supply will be available to eligible commercial customers on the Coliban Rural System again this year.
In southern Victoria, Southern Rural Water increased the allocation for the Werribee and Bacchus Marsh irrigation districts to 30% for HRWS.
At the end of the month, Lake Glenmaggie was at 92.9% of capacity. The allocation for HRWS in the Macalister Irrigation District was increased to 90%, and spilling phase was declared on 19 August.
Restrictions on Unregulated Streams
At the end of August, diversions from a total of 132 unregulated streams and lakes across the state were subject to restrictions. This is similar to the same time last year when 133 streams were on restriction.
Seasonal Climate Outlook
The Bureau of Meteorology issued its latest ENSO Wrap-Up on 18 August. The Bureau reports that major indicators remain at levels typical of a La Niña event.
La Niña events are typically, but not always, associated with above normal rainfall during the second half of the year across large parts of eastern and northern Australia.