Tiaki Wai's $25 billion spending pledge for Wellington - and the $2390 average bill coming your way
Tuesday, 16 June 2026
Tiaki Wai plans to spend $25 billion over three decades to bring Wellington’s water infrastructure up to scratch, and it has given a first glimpse into how much different areas will be expected to chip in.
In two weeks from tomorrow, council rates will drop as the three waters – tap, sewage and storm – get taken over by Tiaki Wai, which will bill home owners directly.
Today it releases its water services strategy showing the average water bill across Hutt Valley, Porirua and Wellington will be $2390 for the first year. That is compared with an average of $2100 currently paid on average across the region via rates.
But the amount will vary based on location and house value. Wellington City will get the highest annual bill of $2417 for a median-valued house while Upper Hutt’s average home will be $466 better off with an average $1951 bill.
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But with rates and water bills expected to rise year-on-year, the total amount leaving household budgets will escalate rapidly.
That average Wellington City house, with a $930,000 valuation, will be paying more than double the water rates by 2033, with an average water bill of $7114 in a decade’s time.
The across-region average will rise from $2390 in the coming year to $6208 in 2036.
Meanwhile, council rates are forecast to increase each year, with Wellington City’s long-term plan showing a big rates decrease as water goes to Tiaki Wai but year-on-year increases from there. However, the new Wellington City Council managed to achieve a significantly-lower-than-forecast rates rise this year and will next year lock in a new long-term plan.
Part of the reason Tiaki Wai was formed under Government legislation is that current water utilities, such as Wellington Water, did not own the water assets so had nothing to borrow against.
The new system saw councils pass on water assets and water debt to Tiaki Wai, meaning it can borrow more – albeit with councils guaranteeing loans from the Local Government Funding Agency.
Tiaki Wai board chairperson Will Peet said the organisation planned to spend $800 million in the coming year with about half going towards replacing and upgrading water infrastructure. It planned to spend $25m over the next 30 years.
About 55% of the money would come from water bills. The rest would come from borrowing and other fees.
Tiaki Wai recently managed to scale back the projected water bill increases for the first few years of establishment but only after councils promised to keep borrowing capacity aside to bankroll any unforeseen large expenses such as a major failure.
Meanwhile, Tiaki Wai’s projections appear to be based on the prediction that, over the next 30 years, 120,000 more people will live across Wellington, Hutt Valley and Porirua.
But recent estimates downgraded population growth with just 800 new Wellington City residents predicted by 2030.
Water bills will initially be based on a mixture of house valuations plus a fixed charge, and will remain that way for waste and storm water. But Tiaki Wai plans to install water metres on residential properties, when the charge will be based on a fixed amount plus the amount of water used.
The first bills will go out in late July or early August, and will go out every three months.