The thing I don't get about building bunkers in NZ it's...ummm... geologically active.
If you look at the South Island, the mountain range going from one end to the other is a big arse fault line just waiting for the next big shift. Following that up into the North Island from Wellington to Whakatane and Whakaari/White Island (you know the one that killed 22 people back in 2019) there's the active volcanoes in the middle and the big lake that is a still active volcanic caldera.