The mayor of New Plymouth says local authorities should be required to pass a warrant of fitness on the state of their water infrastructure.
He estimates it will take a decade and hundreds of millions of dollars to get New Plymouth's infrastructure to a standard where it's "fit for purpose".
Neil Holdom says many other towns and cities are in the same boat.
Holdom was speaking after an extraordinary meeting of the council yesterday where it approved a $4.3 million repair to the thermal drying component of its wastewater treatment plant.
In a report to council, the gas-fired unit - which dries solid waste from sewage for use as fertiliser - was described as being "at risk of sudden and total failure".
The council shut down the unit yesterday pending repairs.
The report blames the poor state of the unit on a 2015 decision to cut back on maintenance because the council's long term plan envisaged it being replaced.
Holdom said the thermal dryer was just the tip of the iceberg.
"I think that there are parts of our water, wastewater and stormwater networks that will be in the same or poorer condition as the thermal dryer."
Council staff were now examining the city's infrastructure with a fine-tooth comb, he said.
"We should be doing what they are doing which is the equivalent of a warrant for your motor vehicle and when your mechanic comes to you with a list of things that need to be done for you to be able to drive the same thing should be done for our infrastructure.
"And we know we wouldn't get a warrant and actually councils across New Zealand wouldn't get a warrant."
Holdom blamed lack of investment from successive councils for the perilous state of the New Plymouth's infrastructure.
"We haven't focused on the core infrastructure because councils have been driven by political imperatives looking at other issues. Keeping rates down you know.
"There's no requirement to undertake a warrant of fitness for your wastewater network or your water network. It's bizarre."
Whanganui Mayor Hamish McDouall said Holdom was onto a good idea.
"It's not the sexy stuff. You know you lay a pipe and it doesn't get you hundreds of votes so the political atmosphere doesn't always favour doing the basic core infrastructural work."
However, McDouall was not sure of the term warrant of fitness.
"But I'd agree that every single council should be very transparent about the lacking in investment and every single council should be able to present to the public 'okay this is what we need to spend to this point'.
"To do an audit and to be very transparent about that is I think a core function of local government."
McDouall said problems underground were not always obvious, for example, it was not until an audit of Whanganui's pipe network was carried out in 2012 that the council discovered wastewater pipes had been incorrectly connected to the stormwater system for about 20 years.