More than 30,000 people across the Wellington region have not paid their first Tiaki Wai bill, with the second round due to arrive soon.
Second bills from the water agency will be sent to Wellington, Lower and Upper Hutt and Porirua residents and businesses from late October.
They come as debate ramps up over whether Tiaki Wai's prices should be capped, and as Wellingtonians stare down a future of price increases which a budget advisor says is causing people in the community deep stress.
Numbers revealed to RNZ show 30,116 residential and commercial customers haven't paid bills for the first quarter yet - 18.5 percent of all accounts.
It shows $21 million in total invoiced bills for the first quarter has not yet been paid.
Chief executive Michael Brewster said Tiaki Wai had received $89.5m of the $110.5m it had invoiced. An extra $3.6m had been paid by people ahead of new bills coming.
Payments had been received from 82.2 percent of residential accounts, 71.2 percent of business accounts, and 76.4 percent of non-profit, community and government organisations, he said.
Brewster said the agency wasn't imposing fines yet on people who hadn't paid, though it was vital the company collected the money needed to fix ageing water networks.
In a briefing to city councillors this week, Tiaki Wai board chair Will Peet said there had been some initial "teething issues" for payments which he expected to settle in time, and those struggling could access the agency's hardship policy.
"Our message to anybody is that if you can't pay, if you've got issues, the sooner you get in touch with us the better we will be able to do that."
In a written response to RNZ, Tiaki Wai said nearly 500 customers spoke to the agency about financial hardship, and nearly 50 customers owing nearly $45,000 collectively had formally entered hardship arrangements.
Tiaki Wai said it did not know how many people were simply refusing to pay their bill in the future.
In comparison, Wellington City Council said it had collected about 95 percent of its rates over the same period - with around $10m outstanding.
Wellingtonian's water bills under Tiaki Wai are increasing by about 13.3 percent this year, in an average total annual bill of $2390.
Forecasts of bills reaching over $6000 per year in a decade has shocked some residents, prompting backlash and protests against the agency in August.
Peet said warned there would be consequences if people were opting out in protest.
"There is a very small group of people who have decided they don't want to pay, I can't see cutting people off as a viable thing.
"Debt collection is probably the next... that would be the step."
Christine Tawhara, a budget advisor in Canon's Creek, said the threat of rising bills was worrying renters coming into the Porirua Whānau Centre.
"Their landlords are looking at a rent increase and that will be to cover the water rates, and the tenant knows that.
"It's real hard for them because then they're going to have to chop back on something if there's a rent increase ... and it's always food, it's always food they chop back on."
Tawhara said the pensioners she was seeing could pay this year's increase, but were stressed about the severity of future bills.
They were currently already avoiding repairs on their house to keep bills down, Tawhara said.
Commerce Commission chairperson John Small told Nine to Noon on Thursday Tiaki Wai's costs - including the debt it had inherited, and the extent of faulty infrastructure it needed to fix - far exceeded the money it currently collected from Wellingtonians.
He was asked whether the company was "technically insolvent".
"I wouldn't say that no, but I do know the directors had that issue in mind before the company was constituted on the 1st of July," Small replied.
"It's ultimately their job to maintain a solvent enterprise."
Small said the commission was imposing extra performance rules to monitor Tiaki Wai was making progress on its plans to upgrade or fix infrastructure.
But he said it would not cap bills right now.
"Right or wrong, affordability is not something that is within our mandate. What our mandate is, is to make sure that the assets are being managed properly and that prices are not out of line with costs."
Wellington mayor Andrew Little said the pressure would now increase on the government to fix its local water done well policy as other regions start to receive their own "extraordinary" price rise projections.
Local government minister Simon Watts recently told RNZ the government had imposed the stronger oversight by the Commerce Commission, giving ratepayers a better picture of performance and applying independent scrutiny.
"Wellington's water infrastructure problems are well known and have built up over decades, and while local Water Done Well has increased the long term financial stability of Wellington's water, the position they've started from has meant the overall costs Wellington ratepayers face have been higher than many other entities stood up through the scheme, some of which have actually reduced expected water charges from what they predicted last year."
He said it was not National Party policy to contribute Crown funding to Wellington's water infrastructure.