Residents are reminded to switch off the sprinklers for winter or risk a $100 fine.

The Water Corporation’s winter sprinkler switch-off began on June 1 and lasts until August 31 to save 5b litres of water – the equivalent of filling Optus Stadium five times.

Residents in Perth, Mandurah, and areas of the south-west and Great Southern are reminded to switch off their sprinkler systems as a drying climate affects water supplies.

The sprinkler switch-off was first introduced in 2010 and officials say it has saved roughly 55b litres of water since then.

WA Water Minister Dave Kelly says the switch-off is vital for protected Perth against climate change and dryer winters.

“The Winter Sprinkler Switch-off is an incredibly effective water efficiency measure and part of a wide range of initiatives to ensure we continue to enjoy a secure, sustainable future water supply,” Mr Kelly says.

“I encourage all households to switch-off now.”

Officials say that being water-wise is now more important than ever, with Perth’s average yearly rainfall having suffered a decline of 20 per cent since 1970.

“We’ve had some extremely wet weather over the past couple of weeks, so I would hope people have done the right thing and switched off early ahead of the Winter Sprinkler Switch-off to help save as much water as possible,” Mr Kelly says.

Residents who fail to follow the switch-off rules will face a $100 fine and a written warning from the Water Corporation.

According to the Department of Primary industries and Regional Development, Perth and its surrounding areas have seen a temperature rise of 1.1C since 1910, with summers becoming increasingly hotter and rainfall decreasing during winter.

Exemptions can be applied for any newly applied lawns and gardens.

Community members are encouraged to report any illegal water usage and sprinkler breaches to Water Corporation through its website.