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

Welcome rainfalls occurred in many locations across the State during the first and third weeks of January. Rainfall totals for the month varied from above to very much above average across most of the west of the State, to below to very much below average in the east of the State. Daytime maximum and nighttime minimum temperatures around Victoria were higher than average.

Streamflows

Given the prolonged dry conditions, catchments across the State are very dry, and despite the good rainfalls throughout January, nearly all streamflows remained well below the long-term January average. At the end of January, about 75% of the State had flows that were less than 10% of the monthly average for January. Half of the reported streamflow stations around the State were recording zero flows, and 60% of streamflows were the minimum ever recorded in January.

Storage Levels

Volumes in the major storages in Victoria reduced by 4% in January. Melbourne Water's storages reduced by 3.5% in January 2007, to finish the month at 36.5% of capacity (18.8% lower than at the same time last year). Rural Water Authority storages decreased by 3.6%, to finish the month at 14% of capacity (32.6% lower than at the same time last year). Storages in the Glenelg-Wimmera Basin were at 4.6% of capacity compared with 8% at the same time last year. At the end of the month, Lake Eildon was at 10% of capacity compared with 38.3% at the same time last year, and Rosslynne Reservoir was at 4.9% of capacity compared with 11.1% at the same time last year.

Urban Water Restrictions

A number of new or increased urban restrictions took effect during January 2007. Key changes include: Stage 1 restrictions were imposed for all towns serviced by Grampians Wimmera Mallee Water via the Northern Mallee Pipeline; Stage 3 restrictions were imposed for all towns serviced by Melbourne Water and Western Water; and Stage 4 restrictions were imposed for all towns serviced by Coliban Water on the Loddon system. The total number of towns subject to water restrictions as at 31 January 2007 was 453 (compared with 136 at the same time in 2006). One hundred and fifteen towns are currently on Stage 1, 57 on Stage 2, 79 on Stage 3, and 202 on Stage 4 restrictions.

Irrigation Allocations

Water allocations for the 2006/2007 season were updated by Goulburn-Murray Water on 15 January 2007. The scheduled end of the irrigation season remains at 15 April 2007. The only change to allocations was an increase to 71% of licensed volume for the Broken system. Emergency drought pumping at the Waranga Basin is still required to support the current allocations. There is still no allocation for irrigation entitlements in the Campaspe and Loddon systems. In the Murray system, the allocation remains at 95% of Water Right and 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%.

In the south-west of the State, because of the low storage situation, irrigation allocations for the 2006/2007 season are very low. Allocations remain at 10% for the Bacchus Marsh and Werribee Irrigation Districts. Levels in the Deutgam Groundwater Management Area are low, and in order to protect the resource from seawater intrusion, allocations for the 2006/2007 season are at 25% of licensed volume. Rosslynne Reservoir is at 4.9% of capacity and the allocation for Southern Rural Water diverters is 5%.

Restrictions on Diversions 

In the south-east of the State, on the Latrobe system Blue Rock Lake is at 63.8% of capacity. SRW licence holders downstream are permitted to take up to their licence volume, but availability is likely to be limited by low unregulated river flows (which normally contribute some 70% of entitlements). Lake Glenmaggie, which supplies the Thomson-Macalister Irrigation District, dropped to 7% of capacity during January. Irrigators in the Northern, Eastern and Tinamba/Riverslea areas remain on a 45% allocation. The seasonal allocation for irrigators in the Nambrok-Denison area has been increased to 50%, due to an increase in water available from Thomson Dam.

Seasonal Climate Outlook

The Seasonal Outlook released by the Bureau of Meteorology on 23 January 2007 for February to April shows a moderate shift in the odds towards above-normal rainfall in western Victoria and along parts of the central coast, with the chances of exceeding the median rainfall being 60 - 65%. Over most of the rest of the State, the chances of exceeding the median rainfall are between 55-60%, with chances dropping to 50-55% in the far east.

All the main indicators suggest that the El Niño event has started to weaken. Since late November, near equatorial sub-surface water temperatures have cooled, and Trade Winds in the western and central Pacific strengthened to near-normal values throughout December. Furthermore, monthly Southern Oscillation Index values were neutral for both November and December, and central Pacific cloudiness near average for almost a month. This is considered to bode well for a switch to wetter conditions across Australia.