Wellington City Council declined Wellington Water a $10 million funding boost because it is not confident the organisation can deliver the work.
Wellington Water asked council for an extra $10m in the next annual plan, but council voted to allocate just $2.3m of the money the water management company said it needed.
Mayor Tory Whanau had partially attributed the city's upcoming 12.3 percent rates hike to a historic underinvestment in the water network.
But in the draft annual plan, council staff recommended against dishing out Wellington Water's full ask because it already had two funding boosts last year, totalling $7m.
That was on top of $1.2 billion dedicated to water infrastructure in the long-term plan.
Councillor Rebecca Matthews, who chaired the long-term plan, finance and performance committee, said water was council's top priority, but the council did not think Wellington Water could achieve the work.
"We still have some questions to ask them which have not been answered, really, about the capacity to deliver the work for the extra $10m," Matthews said.
"We've so far allocated what we have confidence can be delivered in the next year," she said.
"We'll continue to work with Wellington Water, and we have done, topped them up, as we see the case is made for the extra work and have confidence that it can be delivered."
But in a statement, Wellington Water acting chief executive Tonia Haskell said when it provided advice for the annual plan, it made sure it could deliver.
"Our role is to provide advice to all our owner councils on the investment we consider they should make in their water infrastructure for their annual planning and long-term planning processes," Haskell said.
"When we provided 2023/24 investment advice to our councils, we have made sure the outcomes are deliverable," she said.
"The councils then make decisions on investment levels based on their situation.
"In all cases, we adjust our activities to meet the funding available."
Councillor Nicola Young said council should give Wellington Water what it asked for and trust it to deliver.
"Everyone talks about fixing the pipes," Young said.
"Here was an opportunity to give them the money to fix the pipes, and then we decided with no technical expertise, well they couldn't do the work."
Young said she and other councillors suggested ways to cut back on less important spending to bump Wellington Water's coffers, but that was voted against.
The public can have their say on the draft annual plan in April, before it is debated and adopted by council in June.