Melbourne's Water Storages lowest in almost a decade
Melbourne Water’s latest Storage statistics show the city and region’s storage levels dipped to 56.5% in February - the lowest they’ve been at this time of the year since 2011 when still recovering from the millennium drought.
The downward trend in storages over the past five years reflects population driven growth in demand, and less water entering reservoirs.
A changing climate, with longer drier periods, higher temperatures and drier soils have reduced stream flows into reservoirs. Average 2014-2018 streamflows were only 5% above that observed during the Millennium Drought, and 36% below the historic average from 1913 to 1996.
Over the summer of 2018/19 storages dropped by 118 billion litres, or 6.5 % of overall capacity. Storages were at 56.5% on February 28th, a drop of 8.5% from the same time last year.
Storages would have been 4.2% lower without the 76GL of desalinated water received over the past three years.
Melbourne Water’s Acting Executive General Manager Service Delivery Craig Dixon said while it’s normal for storage levels to be falling at this time of year, the state of our storages reflects ongoing low streamflows.
‘Low streamflows to our reservoirs, combined with Melbourne’s growing population has had a significant impact on our storage levels,’ Mr Dixon said.
Melbourne’s population has grown by more than 1.4 million people since 2001 with total annual water usage increasing by 10.7% over the last five years.
The Bureau of Meteorology reported January 2019 as the hottest on record in Victoria and its data shows Victoria’s climate has been on a warming trajectory over recent decades – a trend which is expected to continue in the longer term. Its updated 2019 Autumn Outlook forecasts a drier and warmer than average autumn.
In many catchments, there has been a shift in the streamflow response to rainfall, with less streamflow generated for the same amount of rain.
Summer 2018/19 rainfall over Melbourne’s four major harvesting catchments was 111.8 mm, 45.9% below the 30-year average and less than the 122.5mm during the driest summer of the Millennium Drought. Summer stream flows into Melbourne’s storages were 37.1 billion litres, down from 71.9 billion litres in the previous year and 43.8% below the 30-year average.
Declining storages and the dry conditions are an important reminder to Melburnians to continue to be mindful of the need to use water efficiently. Melbourne’s residential water use in 2017/18 was 161 litres per person per day, six litres above the Target of 155 litres per person per day.
More information on the ‘Target 155’ campaign can be found on your local water retailer’s website or at https://www.water.vic.gov.au/liveable-cities-and-towns/target-155-target-your-water-use
Media: Catherine Garrett 0429 219 084