The WA Government will soon be trucking drinking water into more than a dozen dry towns.

The State Government has been carting 11 million litres of drinking water into 10 towns, and has now announced it will begin deliveries to four more. It will also bring water for livestock into six farming areas.

The state’s Water Minister Dave Kelly wants the Commonwealth to help out.

Farmers and local governments are calling for more investment in dams, pipelines and other infrastructure to take the most advantage of the little water available.

“To have this many water deficiency declarations at one time is unprecedented,” Mr Kelly said.

“And to have so many town water schemes requiring carting at one time is also unheard of.”

Rainfall levels have dropped across southern WA, down by 20 per cent since 2000 in the south-west corner.

The WA Water Corporation has been criticised for allowing state-owned dams to fall into disrepair, after some were decommissioned when towns switched to scheme water.

“It would have been a nonsense five years ago to maintain that water infrastructure when it was no longer required,” Mr Kelly said.

“What we're now finding is that we have the potential to bring some of those old dams back online for non-potable purposes.

“We've spent over $1 million over the last 18 months bringing back online 18 different community water sources.”

Mr Kelly says water carting across the state will cost $11 million by June – an unsustainable situation.

“What we ultimately need is leadership at a national level to deal with the issues of climate change,” he said.

“There are very serious issues relating to water in Western Australia, and if we're going to need to put in additional infrastructure to deal with it, we'd be hoping that the Commonwealth would come to the party.”