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 April, rainfall across Victoria was mostly average to very much above average. Rainfall was above average in most of the western and northern parts of the state and across large areas of the North and South Mallee Districts. Rainfall was very much above average in parts of the Lower and Upper North, West and North Central, and Western Plains Districts. Below average rainfall was recorded in a small part of the West Gippsland District.
High stream flows continued to be recorded in parts of south western and central Victoria at the end of April. Three sites recorded flows well over 100% of the long term average. These sites, Woady Yaloak at Cressy, Mt Hope at Mitiamo and Loddon at Vaughan, recorded flows above 1790%, 806% and 530% of the long term average respectively.
Low flows continued to be recorded throughout the west of the state, with five stations recording less than 10% of the long term average flow for April, and one dry station. East Gippsland also experienced low flows, with one site recording flows at less than 10% of the long term average. Of the 25 flowing stations, all recorded flows higher than the historic April minimum.
The total volume of water held in Victoria’s major storages decreased by 1.6% during April, ending the month at 66.9% capacity. Storage volumes decreased in 13 of the 16 monitored systems, with decreases ranging from 0.3% in the Maribyrnong system, to 6.7% in the Ovens system.
Victoria’s regional storage levels decreased by 1.7% to 67.4% of capacity during April. Melbourne’s storage levels decreased by 0.8% to 64.1% of capacity over the same period. Melbourne’s storages were 4.2% higher and regional storages were 37.1% higher than at the same time last year.
At the end of the March quarter, the short term (<5 years) groundwater level trends were categorised as declining for six of the 14 Water Supply Protection Areas (WSPAs). Groundwater levels were categorised as stable over the short term in eight WSPAs. Over the long term (>10 years), groundwater level trends for nine WSPAs were categorised as stable, two as declining and three as rising.
Of the 40 Groundwater Management Areas (GMAs) in Victoria, groundwater levels were categorised in the short term as stable in 25 areas and declining in nine areas; three were categorised as rising in the short term. There was insufficient information (through lack of state observation bores) to determine a trend in the remaining three areas.
Urban water restrictions
On 23 March, South Gippsland Water placed Korumburra on Stage 1 restrictions. This was due to dry conditions and falling dam levels. This restriction has remained in place for April. All other Victorian towns were subject to Permanent Water Saving Rules. This time last year there were 22 towns subject to water restrictions.
Allocations were increased during April for the Macalister Irrigation District (MID) and the Werribee and Bacchus Marsh Irrigation District (WBMID). Southern Rural Water (SRW) increased allocation in the MID by 5% against low-reliability water share (LRWS) on 11 April 2017, and a further 10% increase in LRWS was announced on 27 April 2017. SRW also announced a 5% increase in LRWS for the WBMID on 11 April 2017. All other systems remained unchanged with seasonal determinations at 100% high-reliability water share HRWS and six systems with LRWS seasonal determinations: Broken, Bullarook, Campaspe, Murray, MID and WBMID.
Restrictions on diversions
At the end of April 2017, across Victoria, there were 66 unregulated streams subject to diversion restrictions, compared to 76 at the end of March. This time last year, there were 150 waterways subject to restrictions.
Seasonal climate outlook
The Bureau of Meteorology (BoM) released its May to July rainfall outlook on 27 April 2017. The outlook continues to predict a dry start to winter for Victoria, with a 20-45% chance of exceeding median rainfall. Northern Victoria is predicted to be drier with less than a 25% chance of exceeding median rainfall over coming months.
The BoM released an ENSO Wrap-Up on 26 April 2017. It announced that El Niño–Southern Oscillation (ENSO) remains in a neutral state, with the ENSO Outlook at El Niño WATCH as there is a 50% chance of El Niño developing in 2017. Sea surface temperatures in the tropical Pacific Ocean have steadily increased since the beginning of the year, however, all indicators of ENSO remain within neutral levels. The Indian Ocean Dipole (IOD) is also currently neutral, though four out of six climate models suggest a positive IOD is likely during winter.
Water for the environment
This section of the Monthly Water Report contains monthly updates on environmental entitlements. Environmental use is reported quarterly.