Auckland Mayor Len Brown's old city of Manukau - home to many of the poorest suburbs in Auckland - is being hit with a 41.4 per cent rise in wastewater charges.
Combined with a 3 per cent rise in rates, that makes the 95,000 households in Manukau the biggest losers of a single rating system for the Super City with an average increase of 10.3 per cent.
The move to a single charge for wastewater has resulted in significant rises and falls across the region with residents in Manukau, Waitakere and the North Shore feeling the brunt of the increases.
The big winners are residents in the old Auckland City, who have been paying wastewater charges based on use through Metrowater, a council company, since 1997 when other councils subsidised the true cost of wastewater in their rates.
Auckland City wastewater charges are falling by an average of 19.6 per cent, although some low water users will pay more.
Mr Brown - the former Mayor of Manukau whose political career began on the streets of Otara - yesterday denied that Manukau had subsidised wastewater through rates.
"Manukau Water had the lowest cost structure for water and wastewater because it had new infrastructure and was efficiently run. It received no subsidy from land rates and benefited from Manukau's growing population," Mr Brown said.
The figures showed other parts of the region were not subsidising Manukau and there were increases and decreases right across the region as the result of the amalgamation of the eight former councils, he said.
"When people get their bills they need to consider all changes rather than simply looking at rates. For example, in the old Auckland City Council area the impact means the combined average rates and wastewater increase is just 1.23 per cent, which is a lot less than some of the alarmist rhetoric being thrown around."
About 242,000 households across the region are paying for wastewater based on use for the first time from this month.
Most households will pay an annual fixed charge of $190 plus $2.28 per 100 litres of water. The price of drinking water is increasing by 3.3 per cent - from $1.30 per 1000 litres to $1.343.
The wastewater fixed charge is based on 78.5 per cent of water that enters a home and reflects the amount of water that goes down the drain via showers, washing machines, toilets, sinks, etc.
Customers who do not have a water meter will pay a fixed wastewater charge of $582 a year.
The fixed charge has outraged many of the 5700 Rodney residents not on the public water supply who have seen a jump of $200 or more for water.
A packed meeting in Whangaparaoa nine days ago heard complaints that people living alone were charged the same as a family of five or six.
Another issue upsetting many ratepayers is Watercare's decision to move from quarterly to monthly billing.
The water company said customer feedback had strongly indicated monthly bills would make it easier to manage home budgets and while it would initially cost more it would create savings over time.
Residents in the former Papakura District Council will continue to be billed by United Water, which has provided water and wastewater services since 1997 to about 15,000 customers under a 30-year franchise agreement.