It's been chronically underfunded. A few years ago, I read that the estimated cost to bring Wellington's sewage and water infrastructure up to snuff was around $12B. Wellington has recently had fountains of crap springing up around town.
I moved away and I'm not really in touch with local politics there anymore, but I would guess they are forced to spend on it. I heard that it's not politically popular to spend money on maintaining infrastructure. Short term limits mean it's always more convenient for local politicians to kick the can down the road.
