Watercare, which handles the city’s water supply, is increasing its charges from the beginning of next month.

It will raise the infrastructure growth charge, which is levied on all new connections to the network, from $9775 to $12,075, an increase of 23.5%.

The Property Council said that was a concern. “It is likely to directly impact on the cost of a new house by increasing development costs. This is analogous to the situation with development contributions, where the Productivity Commission and Central Government have both acknowledged the implications of development contributions on increasing the cost of a new house.”

Auckland president Miles Brown said the increase seemed disproportionate. “These charges must be realistic and not overinflated, otherwise the cost of housing will continue to increase and exacerbate the current housing crisis.”

Watercare is also increasing the cost of water from $1.343 to $1.375 per 1000 litres, the fixed charge for wastewater from $190 to $195 a year and the volumetric wastewater charge from $2.281 to $2.336 per 1000 litres.

Customers who do not have a metered water supply but are connected to the wastewater network will see their fixed charge for from $582 to $596 per year.

Watercare said it was the first price change in two years and would boost the average household bill by less than $2 a month.

It said it would have to spend $5 billion on infrastructure over the next 10 years.