Wetter year bolsters Adelaide reservoirs as summer comes to town

More than double the volume of water has flowed into Adelaide’s 10 reservoirs this year compared to 2024, helping SA Water’s storages recover from extremely dry conditions before the warmer weather returns this summer.

So far this year, 61 billion litres of water has topped up the city’s reservoirs – in stark contrast to only 25 billion litres across the entirety of 2024, leading to a combined storage level of 69 per cent heading into summer, compared to 51 per cent at the same time last year.

Mount Bold Reservoir has experienced the largest increase in its storage level, which is currently sitting at 77 per cent, aided by natural catchment inflows, along with proactive transfers of water from the River Murray.

SA Water’s Senior Manager of Water Futures and Security Dr Ashley Kingsborough said a wet July improved catchment conditions across the Mount Lofty Ranges and helped promote run-off into the utility’s reservoirs.

“After one of the driest 18-month periods on record, rainfall late in July played a significant role in delivering a decent soaking of our catchments,” Ashley said.

“During only one week in late July, a whopping 18.5 billion litres of water flowed into Adelaide’s reservoirs – which increased our combined storage level by 10 per cent at the time, and almost doubled the volume of water stored in Mount Bold.

“However, rainfall in the months that followed was not as significant and didn’t generate sustained volumes of inflow to our reservoirs – apart from November, which was the second wettest in 55 years according to the 74.2 millimetres recorded at the West Terrace rain gauge.

“This delivered an extra 5.6 billion litres of water to our reservoirs, with 1.4 billion of this coming during the last few days of spring.

“While this lifted our current 2025 tally to 61 billion litres, we’re still below our 10-year average of 82 billion litres of water captured by our reservoirs as at this stage of the year.

“This variability is exactly why we don’t solely rely on rainfall to ensure a secure supply of water for Adelaide.

“We also have the River Murray and our climate-independent Adelaide Desalination Plant to underpin the city’s water security, giving us 3 primary sources of water supply.

“Part of our strategy this year has been to maximise our transfers of water from the River Murray in winter and spring, to help our reservoirs recover from their lowest combined level in 20 years and prepare them for summer when demand naturally increases.

“At this stage, the Adelaide Desalination Plant will continue operating at its typical minimum production rate as we’re confident our reservoir storages are sufficient to support customer demand in the warmer months ahead.”

Dr Kingsborough said the warmer months always provide an opportunity to share a timely reminder with its customers about how they can use water more efficiently.

“The bathroom and garden are where the most water is typically used – representing around 75 per cent of total water use – but they’re also the easiest places to save water,” Ashley said.

“For example, just one minute less in the shower each day could save 4,000 litres of water a year.

“By adopting a few simple water wise tips, gardens can also thrive throughout the summer heat, with strategies such as mulching, choosing native plants and watering efficiently to reduce water wastage.

“I encourage our customers to visit sawater.com.au for more tips on saving water in and around the home.”