Water Corporation data shows water use across Western Australia's south-west has dropped in the last 15 years.

Usage per connection has dropped by about 30 per cent compared to 2000.

The Water Corporation’s south-west regional manager John Janssen said communities were now much more water-wise.

“We've seen the introduction of water efficiency appliances in the home and that's really now part of the building code in terms of sustainability and efficient homes,” he said.

“Things like washing machines, showerheads and dishwashers.

“We've seen less water used on gardens, due to water-wise garden design, as well as micro-irrigation systems rather than the old sprinkler types that we used to see.

“The community is very responsible and very aware of the precious environment that we live in and the influence that a drying climate has had on all aspects of our water use ... farming, irrigation, as well as our use on the homes.”

In Perth, individual water use is down by about a third.

“In the last 15 years, Perth's population has increased by over 40 per cent,” Mr Janssen said.

“It's gone from 1.4 million to nearly two million people and the water use during that time has pretty well stayed the same.”

Mr Janssen said the corporation's Water Forever plan would help secure water for the next 50 years.

“That's really by reducing water use ... increasing the amount of water that's recycled ... and where required, to develop new water sources like we have seen in the last 10 years with the desalination plants in Binningup and Kwinana,” he said.

“It's really important we work together to maximise the benefit that our precious resource gives us but we also need to be sure we're planning for the future and that we can meet the growth that we're expecting here in the south-west.”