The Monthly Water Report provides a statewide monthly summary of the status of water resources and water supplies. Each month's report is published online towards the end of the following month. It is based on data provided by Victoria's 19 urban and rural water corporations and rainfall data from the Australian Bureau of Meteorology.

Rainfall

Rainfall was above average in a few areas in northern Victoria and Gippsland. However, in parts of central and western Victoria it was below average.  For the rest of the state, May's rainfall was average.

Stream flows

Heavy rainfall late in May has resulted in an improvement of streamflow at the end of the month, particularly in north-east Victoria. Six of the 28 representative stations, located in East Gippsland and the Alpine region recorded flow above 100% of the long-term May average.

Storages

The total volume in Victoria’s major storages increased slightly (1.9%) to 31.6% of total capacity.  The major regional water storages increased by 2.4% to 31.4%. Melbourne's storages are holding 32.7% of capacity, 0.8% lower than at the end of April.

Restrictions on Urban Water Supplies

During May, Barwon Water removed Stage 2 restrictions for Apollo Bay, Marengo and Skenes Creek.  Western Water reduced restrictions for its towns (including Sunbury, Macedon, Melton and Bacchus Marsh) to Stage 3, in line with Melbourne’s current restriction levels.

At the end of May, 243 Victorian towns were on restrictions, which is significantly lower than the same time last year when 341 towns were on restrictions.

Irrigation Allocations

G-MW made the final allocation announcement for the 2009/10 season on 1 April.  The allocations for high-reliability water shares finished the season at 100% for the Murray, 71% for the Goulburn, 17% for the Broken, 19% for Bullarook and 3% for the Loddon.  The allocation for the Campaspe system remained at zero for 2009/10.

G-MW released a new irrigation outlook for the 2010/11 season on 17 May. The first allocations on the Goulburn and Murray systems are expected on 15 August.

The allocations for the Coliban Rural System and the Wimmera-Mallee irrigation supply system remain at 0%.  However, a 30% emergency supply is available to eligible commercial customers on the Coliban Rural System.

In southern Victoria, the seasonal allocation for the Werribee and Bacchus Marsh irrigation district remained at 14% of HRWS. 

At the end of the month, Lake Glenmaggie was at 37.7% of capacity.  The allocation for HRWS in the Macalister Irrigation District remained at 100%, and the allocation for low-reliability water shares (LRWS) remained at to 45% on 1 April.

Restrictions on Unregulated Streams

At the end of May, diversions from a total of 146 unregulated streams and lakes across the state were subject to restrictions. This is less than the same time last year when 190 streams were on restriction.

Seasonal Climate Outlook

The Bureau of Meteorology released its rainfall outlook for June to August on 25 May.  The outlook predicts a drier than median season for most of Victoria, particularly the south-west.

The Bureau issued its latest ENSO Wrap-Up on 26 May 2010. The Bureau reports that the 2009/10 El Niño event has concluded, as all major indicators are at levels considered neutral (indicating neither El Niño nor La Niña).