The Upper Hutt Mayor says it was obvious the region's water agency was ripping off ratepayers for a long time.
Report findings show a lack of oversight meant Wellington Water was paying nearly three times more to contractors for pipe work, compared with in other areas.
Board Chair Nick Leggett says it means millions of ratepayer dollars wasted.
Upper Hutt Mayor Wayne Guppy says Leggett must resign.
He told Mike Hosking his council smelt a rat for years, but their concerns fell on deaf ears.
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