Winter is coming, but not as we know it

With the winter season around the corner, many of us have taken the puffer jackets out of storage, turned off our sprinklers and warmed up the slow cooker.

But although winter is upon us, it's not the winter we're used to. 

The extended summer has meant some parts of WA have experienced a warmer and drier than usual autumn. Whilst it’s forecast that the South West of WA could receive average winter rainfall this year, it’s more  important than ever that you play your part in helping conserve our valuable water.

Our changing climate 

The effects of climate change on streamflow (rainfall runoff) are more pronounced in Perth and southern WA than nearly anywhere else on earth. 

It's been many years since Perth and southern WA could rely on rainfall alone to meet our water needs. 

Since the 1970s, rainfall has fallen by around 20%, leading to an 80% reduction in streamflow to our dams - leaving our catchments and dams feeling pretty parched.

As a result, total dam storage across the South West was 29.8% in mid-April 2024 – lower than the same time last year. And with whispers of another dry winter on the horizon, we anticipate dam storage levels will reduce even more.

Ensuring water security for a growing population in the face of declining rainfall remains both a challenge and an opportunity for us. That's why we've been exploring alternative, rainfall-independent water sources and helping customers use water wisely for decades.

Record breaking weather trends

We recently spoke with a Water Corporation senior hydrologist and subject matter expert in climate change science, Jacquie Bellhouse, who broke down WA’s rainfall deficiencies over the last 12 months. 

“During the past 12 months, WA has experienced serious rainfall deficiencies across much of the coast, followed by a summer that saw dozens of records broken including extreme heatwaves and countless bushfires,” she said. 

“For the north and central parts of WA, rainfall can be extremely variable due to the influences of tropical lows and cyclones, so it’s difficult to generalise rainfall across the whole region. 

“Summer rainfall was below average along the West Kimberley, the Pilbara, parts of the southern interior, and the south west coast. While most of the remainder of the state was close to average.” 

The Bureau of Meteorology (The Bureau) modelling shows the drying trend in the South West Coast of WA will continue, with rainfall projected to decrease up to 16% by 2030. 

And if you thought this summer was a scorcher, you'd be right in thinking temperatures have been warmer than usual. 

WA sizzled with an average temperature 1.9 degrees higher than the 1961-1990 average - making it the hottest summer on record. In fact, many areas cooked up their hottest summer days ever. 

The Bureau’s long-range forecast predicts maximum and minimum temperatures between June to August have a greater than 80% chance of being unusually warm for most of Australia.

We’re in for a dry winter, with lower-than-normal rainfall expected across the state this month and next.

Water security for customers

We’ve led the nation in adopting innovating , rainfall-independent water sources, commissioning the Perth Seawater Desalination Plant in 2006 , the first large-scale seawater desalination plant in Australia. The Southern Seawater Desalination Plant followed in 2011.

By 2028, the recently announced Alkimos Seawater Desalination Plant will further ensure communities across Perth and some regional areas remain green and liveable for a long time to come, 

For some communities that used to depend on streamflow (rainfall runoff),  we're connecting them to bigger regional supplies. Take Denmark, for example - in 2021 we built a 43-kilometer pipeline in the Great Southern after years of declining rainfall. Now, Denmark is connected to the Lower Great Southern Towns Water Supply Scheme, no longer reliant solely on Quickup Dam.

Driving water efficiency through support to households, businesses, industry, and government is also part of our future water source planning. Every drop of water we save helps defer the need for expensive new water sources.

Find all kinds of water saving tips, tricks water saving advice on our Waterwise page. 

The Winter Sprinkler Switch-off

After our long, hot summer and autumn, now more than ever we need to conserve our valuable drinking water supplies for when we need it most. 

The Winter Sprinkler Switch-off begins this weekend on 1 June, which means it's time to turn off your irrigation. 

Think of it like giving your lawn a well-deserved winter nap. Lawns naturally need less water during this time, and by turning off those sprinklers, we can all save a whopping 5 billion litres of precious drinking water every year – that's enough to fill Optus Stadium 5 times! 

By using water wisely, embracing innovative solutions, and working together as a community, you can help shape WA’s water future, together.