Well, we were surprised again, but we should not have been.

Slow off the mark here, I know, but i really needed some days of sunshine before i could write about the deluge of crap weather we’ve been having lately. I must say, though, that this city never ceases to amaze me. I mean, look at this picture below:

The video is as harrowing as hell – no-one’s front door should be doing imitations of a hydro dam. That was… quite a torrent. Clearly there is a problem with overflow route paths getting too real and far too close to floor level – ie arriving ABOVE floor level, and not passing underneath it. Here’s another overflow route misbehaving – from further up country I believe. But clearly beyond the capabilities of the under-capacity pipe under the road. Nothing that a few mega-girthed ducts under the road couldn’t fix.

I forget where some of these pictures have come from – this one obviously thanks to Stuff, but is it of a back road bush whackers access road? Or is it just the Ohiro Road, which is obviously the route of a stream as well as probably a fault line as well. There’s a lot of rubble coming down the street. Wellington Water sitting there thinking: “We’re going to need a bigger pipe…”

But not as much as the rubble coming down this person’s drive…. along with a torrent of water, which I understand that they were also finding coming through the house as well – so I think they were scooping up some of this rubble to form a rough boulder-bank, to help keep more of the water out. So, a lot of crap to clean up, but not a total disaster I hope. Good swift sensible action, but it also shows that our hills are not so much clay and mud, but instead fractured, weathered greywacke stone, that can be washed away piece by piece. I mean, that material belongs in a riverbed, not a driveway. But then again, also, that driveway is part of the problem. There’s an awful lot of non-porous surface right there.

More Ohiro Road – but where is the usual route for water? It is clearly a river-valley, so there should normally be a river / creek here, but from memory it does not usually come down next to the road.

And I think that this picture (below) is of the same Ohiro Road as shown above, but at the peak of the storm in the depths of the night – that’s a massive volume right there, cascading down the street.

Here’s a WCC ePlan picture of why:

There were undoubtedly a few cars washed away in that storm – below is one sad looking Mini that has washed down a stream. And possibly the house is going to join it.

Officially there was a peak flow of 77mm in an hour, which is probably just a typical Thursday if you live in Greymouth, but is more unusual in Wellington. But it is not completely unheard of or unprecedented in Poneke before – I recall 75mm about 20 years ago, where a sudden deluge in Taranaki Street flooded into a basement garage in Wakefield Street and there were photos of a brand new Beetle floating around in water 6 foot deep. And when the waters recede, they can leave surprises in choice of parking…

And: not enough pipes

That final picture, of a lake, is down the end of Emerson Street, Berhampore, and also the site of the carparking fence on the picture above. The reason it has turned from a quiet suburban street into a greasy brown lake, is because the City Council has built a concrete retaining wall across the end of the road, taking what was a natural watercourse and abruptly stopping it from working. But it is not like this was news – the retaining wall has been there for decades, and the area is noted on the WCC District Plan as being smack in the centre of a major flooding area.

Only made worse, of course, by the retaining wall curiously not shown, making this situation far, far worse. Here’s the context in the wider Berhampore region:

And another key area for flooding was just up the road a little: Palm Grove made a few headlines for inundation too, and here’s why.

We all know that corner, with the Grammercy bakery and badly timed traffic lights, sitting at the curious dip in the road. And now we can tell exactly why there is a curious dip: it’s Godrick’s Hollow, a conspiring confluence of conflicting contributionary streams rampaging through the working class housing in Berhampore. If you are wondering why your feet are always wet round there, this is why.

I’ll just finish up for now with another of Wellington’s repeating wonders of excessive irrigation: Island Bay. Not only is it a major route for tsunami inwards, it is also a logjam for waters trying to get out again. Never mind whinging about the cycleway, here’s the site of your shopping area and a prime zone for urban density. Maybe we don’t need to raise the height level so much as to raise the ground level?

Post script: Raising the ground level was what these developers did out at the Plimmerton roundabout – make a big tall compacted patch of gravel, clearly working fine on their site, but pushes even more water onto the sites next door. Flooding shown from April 18 2026 flood. Earthworks from the next mega-subdivision across the road (bottom right hand corner) caused extensive run-off (and horrid brown water) from all the land they are carving away at the edge of the Taupo Swamp. Future problems happening right now… Idiotic development !!

Fish

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