A year after earthquakes and floods

Published 1 December 2017 by Keith Calder MEIANZ CEnvP, NZ Chapter

It sounds like an apocalyptic story from the Bible: a year on from the Kaikoura earthquake and the unrelated rainfall and flooding that followed, we've experienced our fourth ‘20 year flood event’ in two years here in Porirua City. The rainfall pattern – duration, locations – have all been different, but the results were  the same: the CBD awash with ‘road rivers’ and shopping precinct a lake; any dip in suburban roads filled with water too deep for vehicles to negotiate, and the same properties inundated with water and mud. Hillsides falling down, harbour filling in and a beach going 'missing' (I kid you not!), exacerbated no doubt by the good shaking-up by the quake. All the time wondering what the next extreme high tide will bring!

The question arises repeatedly. Why do we get four 20-year floods within two years? Now, following ‘the Summer-that-time-forgot’ and it seems to have never stopped raining since then, there is no sense of the weather and weather events settling. Apart from the difficulty of explaining statistical terminology or finding a better way of expressing it, it’s hard to ignore the none-to-subtle changes that climate change is already expressing itself in the world, even here in Porirua.

I’m glad that EIANZ has a Climate Change specialist CEnvP group. But as an EIANZ member and common ‘garden variety’ CEnvP generalist, I am conscious of my ethical commitment and that I don’t have the luxury of ignoring, not just the science, but the overwhelming weight of science, surrounding climate change and sea-level rise. My own local experience (rain & more rain!) and observation (tide gauge records) resonates with this science.