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.
For a weekly snapshot you can now download the Department's Weekly Water Report on the Water Register website.
During February, rainfall in Victoria was mostly average with areas of above average rainfall in the state's northwest and in parts of the south. Large areas of the Mallee and North Wimmera Districts and parts of the West Coast and East Central Districts received above average rainfall. Below average rainfall was recorded only in a few patches, mostly in the east of the state. Overall, Victoria experienced its highest February rainfall since 2013.
Moderate stream flows were recorded in parts of north eastern and south western Victoria at the end of February, with three sites recording flows over 90% of the long term average. These sites, Merri River at Woodford, Snowy Creek at Granite Flat and Rose River at Matong North, recorded flows above 125%, 91% and 92% of the long term average respectively.
Low flows continued to be recorded throughout the west of the state, with the exception of Merri River at Woodford in the south west. Of the 28 representative stations across Victoria, 11 sites recorded flows at less than 10% of the long term average for the month, five of which were recorded as dry.
The total volume of water held in Victoria's major storages decreased by -4.1% during February, ending the month at 73.6% capacity. Storage volumes decreased in all of the 16 monitored basins, with decreases ranging from -1.9% in the Maribyrnong system, to -19.6% in the Ovens system.
Victoria's regional storage levels decreased by -4.4% to 74.7% of capacity during February. Melbourne's storage levels decreased by -2.3% to 67.3% of capacity over the same period. Melbourne's storages were 3.0% higher and regional storages were 38.4% higher than at the same time last year.
At the end of the December quarter, the short term (<5 years) groundwater level trends were categorised as declining for six of the 16 Water Supply Protection Areas (WSPAs). Groundwater levels are categorised as stable over the short term in 10 WSPAs. Over the long term (>10 years), groundwater level trends for 12 WSPAs are categorised as stable, one as declining and three as rising.
Of the 40 GMAs in Victoria, groundwater levels were categorised in the short term as stable in 26 areas and declining in seven areas; one is categorised as rising in the short term. There continued to be insufficient information (through lack of state observation bores) to determine a trend in six areas.
Restrictions on urban water supplies
There were no towns on water restrictions at the end of February. All Victorian towns are subject to Permanent Water Saving Rules. This time last year there were two towns subject to water restrictions.
Allocations were increased during February for the Werribee/Bacchus Marsh District and Murray system, with a 5% increase in low-reliability water share (LRWS) allocation in each. All other systems remained unchanged with seasonal determinations at 100% high-reliability water share (HRWS) and four systems with seasonal determinations against LRWS: Broken, Bullarook, Campaspe and Werribee/Bacchus Marsh District.
Restrictions on diversions from unregulated streams
At the end of February 2017, across Victoria, there were 75 unregulated streams subject to diversion restrictions, compared to 58 at the end of January and 34 at the end of December. This time last year, there were 149 waterways subject to restrictions.
Seasonal climate outlook
The Bureau of Meteorology (BoM) released its March to May rainfall outlook on 23 February 2017. The outlook has changed from the February to April 2017 predictions and now indicates a drier start to Autumn is likely for most of Victoria, with a 20-35% chance of exceeding median rainfall. Central Victoria is predicted to be drier with a 20-25% chance of exceeding median rainfall over coming months.
The BoM released an ENSO Wrap-Up on 28 February 2017. It announced that ENSO remains in a neutral state. Recent changes in the tropical Pacific Ocean and atmosphere suggest a rise in likelihood of El Niño forming in 2017 putting it at a 50% likelihood. Climate model outlooks indicate that the tropical Pacific Ocean will likely remain ENSO-neutral throughout summer and autumn. Most models indicate the central Pacific Ocean will warm during this period, meaning La Niña is the least likely scenario for winter/spring 2017. However, it should be noted that model outlooks that span the autumn period tend to have lower accuracy than at other times of the year. The Indian Ocean Dipole has little influence on Australian climate through December to April.