While it is sad to see the mighty Queen City of Auckland brought to its knees over some rain, it is nice not to have Aucklanders constantly be rude about Wellington weather. And also: note that none of us down here are making fun of them up there, knowing full well that, there but for the grace of God, go us.
But first up, something to make you happy on a sweaty Wednesday. A rock band, which surely can only have come straight from the 1980s, with a rocking anthem that just seems appropriate.
There! Happier now? But you have to wonder – or at least, I have to wonder – just how would we cope with a weather stream like this? We don’t need to wonder for long of course, as just before Christmas I recall we had a spell of non-stop torrential rain which broke heaps of records and caused lots of slips and destruction. Don’t tell me you have forgotten already?!?! No, of course you haven’t – nearly everyone has a nearby slip that either happened to them or happened to their neighbour, although I don’t think anyone actually drowned in Wellington’s
imbroglio (no – wrong word, but I like it) cataclysmic inundation. We had part of the Terrace fall down and the road be closed for weeks on end. We had slips in the Hutt, probably both of them, and slips on the Kapiti Coast, including that monster slip on the old SH1 that they are still working on till the end of February. Serious stuff. As always, people with underground basements had them flooded out, which makes me wonder how come people in Europe and North America have basements, and yet don’t get flooded out?
Still though, our rainfall event was a lot smaller than Auckland’s, or maybe it was a similar size but spread out for longer. 300mm is a lot of water to cope with, all at once, although to be fair, Fiordland gets that amount daily, sometimes, I believe. Back in about 2001 I recall we had 75mm in half an hour, and everything in central Wellington flooded, and there were cars floating about in a CBD basement – congratulations Volkswagen, you make a pretty waterproof car!
But the band of rain is headed our way and may be with us soonish. Most weird, humid weather I’ve seen for ages – hate to say it, but I’m dying for a bit of a breeze! Shall just have to continue to go swimming in the ocean, as that’s somehow more preferable to just having a cold shower. I like the crusty feeling of salt in my hair and on my skin, rather than just smelling of chlorine, as our water does now.
The real question, of course, is the big question – what happens if / when we get a deluge this size happening in Wellington? What is our equivalent of the Wairau Valley? We’ve got to remember that Auckland is a city built on 50 volcanoes, which means they have a lot of cold hard lava to build on top of. By comparison, Wellington has famously rotten rock, mostly greywacke, and the multitude of faults over the years means that the rock is already severely fractured. On top of that, our dirt seems to turn quite easily to mud, and let’s face it, a lot of houses here would slide merrily down the hillside. Where would all that water go to – and where would it all come from?
Well, history has already given us some helpful pointers of course. The classic instance is the Zealandia complex in Karori, with the Upper and Lower dams. Built over a 100 years ago in order to supply Wellington with water, Wikipedia tells me that they were decommissioned only in 1991, and the level of the top lake lowered to the very much lower level that it sits at now. It seems that at some stage prior to 1991, someone did their homework and figured out that if the hundred year old dam failed, and the water came down the valley, it would eventually exit out at Woodward Street. Some of you may know more about that than me – please write in or comment if you do – I’m guessing that it is a simple matter if we just follow the route of the Kumutoto Stream, as that is the one that comes down Woodward Street and out to sea next to that funny looking bridge near the Meridian building. I’m going to leave a blank here because I want to find a contour map and see if I can make sense of it.