Monthly Water Report
Monthly Water Report
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.
In October, most of Victoria received average to above average rainfall, with some areas (particularly in the west) receiving very much above average rainfall. Across the state, rainfall was 26.5% above average – the highest October rainfall since 2010. The highest daily rainfall total in Victoria was recorded at Parkers Corner in Erica which received 54 mm and nine sites across the state recorded the highest total rainfall in October for at least 20 years.
Moderate to high streamflows were recorded throughout the north east and north west of the state during October. Of the 28 representative stations monitored, 27 recorded flows in October. Five sites across the state recorded flows over 100% of the long term average. The highest average flows in the state for October were recorded for the Suggan Buggan River at Suggan Buggan, Snowy Creek at Granite Flat and Tallangatta Creek at McCallum with flows above 135% of the long term average.Small sections in the central and south east coast of the state continue to remain dry.
The total volume of water held in Victoria's major storages increased by 9.4% during October, ending the month at 79.5% capacity. Storage volumes rose in 12 of the 16 monitored basins, with increases in storage ranging from 1.1% in the Latrobe System to 12.9% in the Murray System. Storage volumes decreased in four basins, with decreases ranging from -0.9% in the Bendigo System to -9.8% in the Ovens System.
Victoria's regional storage levels increased by 10.4% to 80.8% of capacity during October. Melbourne's storage levels increased by 3.6% to 71.9% of capacity over the same period. Melbourne's storages are 1.3% lower and regional storages are 28.1% higher than at the same time last year.
The groundwater section of the Monthly Water Report is updated on a quarterly basis. For the last update go to the September 2016 report.
Restrictions on urban water supplies
There were no towns on water restrictions at the end of October. All Victorian towns are subject to Permanent Water Saving Rules.
Allocations were increased for all systems during October except the Bullarook and Coliban Rural systems (already at 100% allocation since the end of August 2016) and the Macalister Irrigation District (MID). In July 2016 the MID received 100% against high-reliability water shares (HRWS), and no further allocation will be made until after the end of the spill period on 15 December 2016. At the end of October there were four systems with seasonal determinations against low-reliability water share (LRWS): Broken, Bullarook, Campaspe and Werribee/Bacchus Marsh District.
Restrictions on diversions from unregulated streams
At the end of October 2016, across Victoria, there were three unregulated streams subject to diversion restrictions, compared to none at the end of September. This time last year, there were 72 waterways subject to restrictions.
Seasonal climate outlook
The Bureau of Meteorology (BoM) released its November to January rainfall outlook on 27 October 2016. The outlook for Victoria is now showing a 50% chance of exceeding median rainfall heading into 2017, downgraded from an 80% chance in the October to December outlook. Areas in western Victoria are the most likely to have above median rainfall, with a greater than 55% chance of this occurring. The next update is expected on 24 November 2016.
The BoM released its latest ENSO Wrap-Up on 25 October 2016. It announced that the tropical Pacific Ocean remains in a neutral El Niño–Southern Oscillation (ENSO) state. Most international models indicate that sea surface temperatures in the Pacific Ocean will remain ENSO-neutral, though cooler than average, until the end of the 2016-17 summer. Two of eight climate models suggest brief, weak La Niña levels may occur towards the end of the year. As a result, the Bureau's ENSO Outlook remains at La Niña WATCH, which means there is a 50% likelihood of La Niña developing towards the end of 2016. Warmer than average sea surface temperatures around Australia's north suggest that some La Niña-like impacts are likely, even if an event does not fully develop.
Negative Indian Ocean Dipole (IOD) conditions continue, which have been occurring since late May 2016. Warmer sea surface temperatures east of tropical Africa weakened through October, but remain very much above average to the south of Indonesia. Models indicate that the IOD is likely to return to neutral by the end of spring. As at the end of October 2016, the next ENSO update is expected on 8 November 2016.