Securing supply
We have long term plans to secure a climate resilient water future that will support Perth's water needs for generations to come.
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Our water & Perth
Perth is the sunniest capital city in Australia with a long-term average of 8.8 hours of sunshine per day. But those sunny days come at a cost to Perth’s rainfall average. Due to climate change, Perth’s average annual rainfall has reduced around 15% since the 1970s.
It’s not just the total volume of rain that’s changed, but also how and where it falls. The rainy season starts later in the year, meaning we experience more sunny days during winter. Rainfall is also more irregular, so catchments generate less consistent runoff. As a result, much less water flows into our rivers and dams - in some cases up to 80% less than before.
Climate change has dramatically affected the sources of water for our largest drinking water scheme. The Integrated Water Supply Scheme can't rely on rainfall as it did in the 1970s and now includes desalinated seawater and groundwater replenishment.
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Facts & figures
Before 1975, Perth’s dams received an average of 420 billion litres of streamflow each year, enough to supply Perth's population of two million people.
In comparison, between 2010-2024, Perth’s dams received an average of 75 billion litres of streamflow per year. Further evidence of climate change is the increased annual number of days in Perth over 35 ℃.
In 2015, Perth’s dams received the lowest level of streamflow since records began in 1911 – with 15.8 billion litres of water. To put that into perspective, it’s only enough water to supply Perth for around 14 hot summer days.
We’ve been responding to these changes to secure Perth's future water supplies by working towards our long-term targets outlined in Water Forever 50 Year Plan. This plan adopts a three-pronged approach, which includes:
- Working with the community to reduce water use to help defer the need for investment in further new climate resilient sources
- Developing new water sources where necessary
- Increasing the amount of water recycled
Water for the Integrated Water Supply Scheme is now comprised of a combination of sources, including desalinated seawater, groundwater, groundwater replenishment and rainfall runoff into dams.
Did you know?
Australia’s first full scale Groundwater Replenishment Scheme is located at Craigie, in Perth’s northern suburbs. It started recharging recycled water to Perth’s deep aquifers in 2017. It has the capacity to recycle up to 28 billion litres a year, with half of this water recharging the Leederville and Yarragadee aquifers onsite and the remaining volume of water being transferred to recharge bores drilled in Wanneroo and Neerabup.
We can all help
We can all take action to fight climate change and reduce our water use. Find out what you can do to save water starting today.