But the biggest industries and employers, which use up to a million litres of water a day for their products, have banded together to put their view to the company and the council.
"Some of the parties will be greatly affected - to their detriment," said lawyer Mai Chen, of Chen Palmer, representing some key players in talks with Watercare and Mayor Len Brown.
Auckland Chamber of Commerce chief executive Michael Barnett said Watercare was putting up four tariff options, each combining an annual fixed charge with a volumetric charge based on the fresh water coming in through the meter. The chamber was concerned about the situation facing two groups under an Auckland-wide tariff.
These were the big users of water and a group of small to medium businesses who had enjoyed favourable terms under the former council water retail companies before amalgamation.
Wastewater charges that cost more than $200,000 could increase to more than $1.5 million under the formula proposed.
"We cannot allow a situation in which otherwise competitive, successful businesses are put out of business because of an increase in wastewater charges," Mr Barnett said.
Watercare increased wastewater costs by 4.5 per cent in July 2011 and by 3.6 per cent in July 2012. It has a revenue target of $111 million from wastewater in 2013-14, based on a price rise of 3.75 per cent.
Ice-cube maker hot under the collar
After 20 years of making ice cubes for drinks, picnics and freshly caught fish, East Tamaki's Warren Goudie (picture) could do with some cooling down himself.
He has learned that Watercare Services plans to bring in a single wastewater tariff for all its 22,000 business customers in Auckland.
But he has an agreement with the council-owned company which recognises that although his business draws a lot from the fresh-water mains, it goes into the product rather than down the drain.
However, the proposal means not only an annual fixed charge for wastewater but also a volumetric charge based on how much fresh water flows through the meter.
Now the Coolit Ice plant's busy Christmas holiday rush is over, Mr Goudie plans to meet Watercare officials to find out how the proposal will affect business expenses.
"We can do 100 tonnes of ice a day in summer but there is no wasted water - it all is recycled to be put through the refrigeration plant. We have no nasties going down the drain - it's clean water."
The plant sends its ice to shops from Cambridge in the south to Kaitaia in the north.
In the summer season, it can use more than 40,000 litres a day and employ 30 people. Wayne Thompson