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

Rainfall in Victoria during November was generally average to above average with the south-west of the state and parts of West Gippsland being very much above average. The month of November started with promising rainfalls over the whole state. Although the rainfall intensities weren’t great, falls were steady, lasting up to 4 days in some areas. Despite some local flood events in Gippsland and the northeast, the rain was not sufficient to recover the State’s major storages or have a large influence on irrigation allocations.

Melbourne received 66.2 mm of rain during the month, which is above the long-term November average of 59.5 mm. The average maximum temperature was 24.4°C. This is 2.5°C higher than the November average.

Streamflows

At the end of the month, half of the monitored streams were recording flows of less than 10% of the long-term average for November (compared with 82% of monitored streams at the end of October).

Storage Levels

The high level of restrictions to towns and low allocations for irrigators is a consequence of depleted volumes in the State’s major storages. Rural water corporation storages decreased by 0.1% to finish the month at 24.2% of capacity (3.2% higher than at the same time last year). Grampians Wimmera Mallee storages remained stable at 5.7% of capacity (same as this time last year). Volumes in major northern storages declined in all but the Goulburn Basin, and southern storages generally rose or remained stable following above average rainfall. Melbourne's storages increased by 0.2% in November to finish the month at 40.0% of capacity (1.5% lower than at the same time last year). Storages in the Ovens Basin and Glenmaggie ended the month at full storage levels.

Urban Water Restrictions

375 Victorian towns were on restriction as at 30 November. Sixty three towns were on Stage 1, 49 were on Stage 2, 19 were on Stage 3, 18 were on Stage 3a, 111 were on Stage 4 with general exemptions and 115 were on Stage 4. There were a number of changes to urban water restrictions during November: Wannon Water reduced Stage 4 restrictions to Stage 3 for Hamilton, Cavendish, Dunkeld and Tarrington and to Stage 2 for Glenthompson; North East Water increased Stage 3 restrictions to Stage 4 (with exemptions) for Devenish, St James and Tungamah: and Central Highlands Water increased Stage 2 restrictions to Stage 3 for Allendale, Broomfield, Kingston, Newlyn, Smeaton and Springmount.

Irrigation Allocations

At 30 November, irrigation allocations were still extremely low across Victoria except for Gippsland. During November, allocations increased in the Goulburn, Murray, Broken and Campaspe systems. The gravity irrigation season was extended to 15 May 2008 for the Murray system. Broken system customers had continuous access to water until 30 November 2007, whilst customers in the Loddon and Campaspe systems had rostered access. There was not enough water in the Bullarook system for an irrigation allocation and irrigators remained on qualified right to water for essential stock and domestic needs only. Coliban Water’s rural season remained at 30% of licensed volume. Werribee and Bacchus Marsh irrigation districts have an allocation of 5% and irrigators cannot access groundwater in the Deutgam Groundwater Management Area this season.

In contrast, the Macalister is set for a more promising season. The November floods re-filled Lake Glenmaggie, allowing Southern Rural water to declare off quota until 15 November with an allocation of 100% starting from that time. On the Latrobe River, licence holders downstream of Blue Rock were able to pump from unregulated flows in November and a formal allocation will be announced once unregulated flows drop away.

Restrictions on Diversions

At the end of November, diversions from a total of 129 streams and lakes across the State were subject to some form of restriction, which is significantly less than the same time last year when 175 streams were on restriction.

Seasonal Climate Outlook

The Bureau of Meteorology released the latest rainfall outlook on 22 November. The outlook for the summer (December to February) quarter indicates that the chances of exceeding the three-month median rainfall are between 45% and 60% across most of Victoria. However, the probabilities drop to around 40% along the State’s southwest coastal fringe.

A La Niña event was well established in the Pacific Basin with further intensification over late October and early November. The main characteristics are colder than average temperatures along the equator, both on and below the surface, stronger than average Trade Winds and reduced cloudiness. Computer models indicate it will persist at least until at least autumn 2008. Ocean temperatures immediately to the north and northwest of Australia warmed during October and November, although they remained somewhat cooler than would normally be observed during a La Niña event. This would suggest an increased chance of a more typical La Niña rainfall pattern over Australia over the coming months.