Ben Lomond Water, formed in July 2009, issued its first batch of water usage bills to thousands of customers this month.

The corporation has struggled to create a universal billing system since taking over from eight councils.

In the past, residents received their water usage charges as part of their council rate notices.

Northern Midlands and Break O'Day residents were the first to receive their bills followed by West Tamar residents who should receive their bills this week.

Property owners in the remaining municipalities will be billed within weeks.

A Ben Lomond Water spokeswoman said the mailouts had created a spike in calls from concerned customers.

She urged customers worried about making the payments within the standard four-week period to call and a payment plan would be worked out.

"A lot of people are concerned about the amount and that's fair enough. If you've got a large account please get in touch with us."

Ben Lomond Water has apologised for the backlog that has caused charges to accumulate.

The corporation hopes to implement quarterly billing from July.

The spokeswoman said the amounts were accurate.

"The reads have been taking place, we're not just plucking these numbers out of thin air."

Owners of rental properties may pass on the bill to tenants but those with new tenants will be forced to meet the cost.

Home owners who have recently moved into their home will only be charged for the water used since they moved in. Premier and Treasurer Lara Giddings would not comment on the day-to-day operations of the corporation.