Wellington Water admits overlooking $51 million budget error

Wellington Water has admitted overlooking a budget error that has resulted in an extra last-minute bill for councils of $51 million over three years.

At a meeting of the Wellington Water Committee Friday morning, board member Pat Dougherty apologised on behalf of the organisation and promised an independent inquiry.

He told angry mayors and councillors around the table that Wellington Water was conscious that this came at a time when councils were coming to the end of the hardest long term plan process many had ever faced, with "terrible pressure on operating budgets".

"It's the worst time in 20 years to make a mistake like that, and the worst moment to find out about it," he said.

"To make matters worse, those councils who heard our message and ramped up capex [capital expenditure] are the ones worst affected."

The board and staff were "devastated" and felt "stunned that this has happened".

"We've worked hard to provide robust information and I feel over the last 15 to 18 months we've done a good job of that. We want to be a trusted adviser but we've shot ourselves in the foot with this.

"We need to start building that credibility again and we will."

With a view to rebuilding trust, the board was commissioning an independent review of its systems and processes to find out how this mistake was able to occur and why it took so long to come to light and for the scale of it to become apparent.

It would aim to present that report to the committee at its next meeting in late July.

Porirua mayor Anita Baker said she was furious and questioned how long Wellington Water had been aware of the error.

"I understand you knew about this three or four weeks ago."

Dougherty said one of the matters the review would consider was why it took so long to realise the size of the mistake.

Upper Hutt mayor Wayne Guppy - a long-term critic of Wellington Water - told the meeting he was "not surprised" by the latest debacle.

"This organisation has gone from crisis to crisis."

Wellington Water chief executive Tonya Haskell said she echoed the board's apology and staff were feeling it "very keenly".