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 the State’s 20 urban and rural water corporations.

Rainfall

October rainfalls were ‘very much below average’ across most of the State with some areas recording the lowest totals on record. Overall, average rainfall across Victoria for October was the lowest on record since 1914. Furthermore, Victoria recorded its hottest mean maximum temperatures for October since records began in 1950, putting further pressure on water resources.

Streamflows

Given the prolonged dry conditions, catchments across the State are very dry, and the limited rainfalls in October resulted in almost all streams showing a further deterioration in flows relative to the monthly average. At the end of October, ninety-five percent of the State had streamflows that were less than 10% of the long-term average flow for the month. Flows recorded at nearly half of the gauged stations (13 out of 28) are the minimum ever recorded during October, and 9 of these stations recorded zero flows.

Storage Levels

Volumes in the major storages in Victoria reduced further by 4% in October compared with an increase of 2.9% at the same time last year. Melbourne Water's storages reduced by 2.5% in October 2006 to finish the month at 43.4% of capacity (16.8% lower than at the same time last year).

Rural Water Authority storages decreased by 4.3% to be at 24.2% of capacity (32.6% lower than at the same time last year). Storages in the Glenelg-Wimmera Basin are at 5.7% of capacity compared with 10.9% at the same time last year. At the end of the month Lake Eildon was at 17.2% of capacity compared with 27.7% at the same time last year, and Rosslynne Reservoir was at 5.95% of capacity compared with 14% at the same time last year.

Urban Water Restrictions

A number of new or increased urban restrictions took effect during October and in early November 2006. Stage 1 restrictions were imposed for all towns in the Central Gippsland and North East Water regions. Stage 2 restrictions were imposed for Mansfield, Sunday Creek, Apollo Bay, Skenes Creek, Marengo, and all towns serviced by Western Water, Melbourne Water, and the Tarra River system.

Stage 3 restrictions were imposed for Birregurra, Forest, Hamilton, Tarrington, Cavendish, Dunkeld, and all towns in the greater Geelong and Bellarine Peninsula, and those serviced by the Loddon system. Stage 4 restrictions were imposed for Glenthompson, Balmoral and all towns serviced by the Ballarat system and in the Westernport region.

The total number of towns subject to water restrictions from 4 November 2006 was 314 (compared with 178 at the same time in 2005). Ninety-four towns are currently on Stage 1, 40 on Stage 2, 69 on Stage 3, and 111 on Stage 4 restrictions.

Irrigation Allocations

Water allocations for the 2006/2007 season were updated by Goulburn Murray Water on 1 November 2006. Record low rainfalls and inflows occurred across much of the G-MW region during October. G-MW confirmed that emergency drought pumping at the Waranga Basin is required to support the current allocation.

There is still no allocation for irrigation entitlements in the Campaspe and Loddon systems. The Goulburn system allocation increased during October from 21% to 23%. In the Murray system, the allocation increased to 95% of Water Right and Licensed Volume. In the Broken system the allocation increased to 60% of Licensed Volume. In the Bullarook System, customers supplied from Newlyn Reservoir have an allocation of 36% and the customers supplied from Hepburns Lagoon still have an allocation of 0%.

South of the Divide, because of the low storage situation, irrigation allocations for the 2006/2007 season are very low. In the south-west, allocations increased to 10% for the Bacchus Marsh and Werribee irrigation areas. This increase was made possible by a decision to pump dead storage from Pykes Creek Reservoir. A range of other measures are in place to assist in ameliorating the supply situation in this area. Levels in the Deutgam Groundwater Management Area have been declining through 2005/06 season, and in order to protect the resource from seawater intrusion, allocations for the 2006/2007 season are at 25% of licensed volume.

In the east of the State, water availability on the Latrobe system is satisfactory with Blue Rock being at 77.8% of capacity, and an allocation of 100% has been made for diverters from this system. Lake Glenmaggie, which supplies the Thomson-Macalister Irrigation District, dropped to 26.9% of capacity; however, irrigation allocations increased to 45%. Rosslynne Reservoir is just below 6% of capacity and the allocation for Southern Rural Water diverters is 5%.

Seasonal Climate Outlook

The Seasonal Outlook released by the Bureau of Meteorology on 26 October 2006 for November to January indicates the chances of above median rainfall are 40-45% across northern Victoria, increasing to 45-50% in the south. Chances of exceeding median maximum temperatures are 60-65% across the State. There was a general strengthening of all El Niño indicators during October with the event ‘primed’ to enter the maturing phase. Computer models indicate that this event is likely to peak around January/February 2007.