TASMANIA is witnessing Australia's largest water meter rollout in history and it's on deadline, the state's three water authorities said.

The $58 million project will see tens of thousands of automatic reading meters installed.

Ben Lomond Water will spend $11.77 million on about 58,000 new meters.

Some will be attached to water connections that have never been metered but most will replace older meters.

The impetus for the massive overhaul is a state government deadline to introduce two-part pricing water bills by the start of July.

The government want bills to display consumption and infrastructure charges separately - a reform designed to cut water usage and reflect the true cost of water.

Ben Lomond expects lower labour costs because workers will collect reads wirelessly rather than going to door-to-door to conduct manual reads.

The biggest shake up has occurred in the South, where Southern Water is spending $33 million on installing 60,000 meters.

Most will go to households which have never had them.

Cradle Mountain Water, which covers the North-West, expects to install 15,000 meters for $13 million.

Ben Lomond said that its metering project would not lead to more expensive bills.

``There will be no additional charges because that infrastructure belongs to Ben Lomond Water and it's our responsibility to maintain it,'' a spokeswoman said.

The rollout comes as 16 towns in the North remain on permanent boil alert because of unsafe drinking water.

Ben Lomond said that the project ran parallel to its capital works program and was not being prioritised ahead of water quality improvement.

Local Government Association Tasmania president Barry Easther said that it had been incumbent on the authorities to introduce two-part pricing since they took control of water and sewage from councils in 2009.

``I can understand people saying the money should be directed elsewhere but it was always very clear that meters had to be installed,'' he said.

Ben Lomond said that most of the meters being replaced were at least 20 years old and some still measured in gallons.

Last year the amount of water consumed in Launceston matched the amount used in 1985, when most of the municipality started using meters.

Ben Lomond said that the meters would make it easier to locate leaky pipes and other leakages, reducing maintenance costs.

The next major development in reform is likely to be a new single water authority.

Both major parties have backed a single body and councils, which own the three authorities, are set to discuss it at the association meeting next month.