Dredgers in Paradise

One of the dangers of best-kept secret rivers is that they are more easily trashed. I have long known this, and more than once before have had to open up on the name of a beautiful stream that I enjoy walking and fishing in order to shout loudly how important it is.

I’ve not done this in New Zealand before, however, have not ever felt it was my place to. And I know that Kiwis, fishing guides especially, don’t like the names of their secret spots broadcast far and wide. So, I’ll keep the name of this place quiet for now – if you know it, you’ll know it – at least until I can find out more about the reasons behind what I saw yesterday.

Because yesterday, I felt like giving up. I was totally in the dumps. The struggle to champion the cause of pastoral spring streams (chalk streams being in that group, and at the very apex of pressure caused by humans) feels too much like an uphill one at times.

I’m on a tour of New Zealand with Simon Cain – also a passionate river-restorationist who I have known since 1991 – showing him all the unspoilt spring-creeks I have been going on about for so long, the rivers I like to model river restoration ideas on. I told him the stream we were going to look at was one of my favourites: “It’s kind of like the upper Frome,” I said. “Only maybe a 13th century Frome.”

You could pick all sorts of holes in my comparison. There were no mills on this stream. There are no mountains to the side of the Frome. But it painted a picture. And indeed this stream has also worn the impact of farming quite heavily in places, over the years. It is abstracted by pumps. One farmer on it makes no effort whatsoever to fence out the livestock and the riparian edges in that reach are nibbled and puddled bare. The very headwaters, which were once a marsh supporting the base-flow, have been arterially straightened in the past.

But somehow the river was still just lovely. And I have often cited the lowermost farmer – when chatting to other farmers, many of whom are not that happy about the new NZ law compelling the fencing out of livestock (it is causing problems with overgrowth of rank marginal vegetation) – as having managed the riparian strip to perfection ever since I had known the place and long since before the new law: a fence twenty to fifty meters back and very occasional grazing on the stream side. He had presided over a true spring-creek paradise.

Which is why I suspect the farmer here is not to blame. Why, having been apparently perfectly happy for many years with the co-existence of his farming and his spring-fed stream, would he suddenly take a hatchet to the latter and hack it to bits?

We noticed the silt on the bed as soon as we arrived, noticed spoil on the bank by the first pool: rocks and stones and dusty, ex-riverbed the colour of light earthenware under an unnaturally vivid green flush of nettles and docks and thistles: all the stuff that loves the arrival of river-bed nutrients on top the of the floodplain where they don’t belong.

My thought was a resigned “that’s a shame”. We were near a bridge and I know farmers do get a bit heavy handed with the digger around bridges, in a (usually misguided) effort to create greater conveyance of flow.

But then around the next bend we saw more of the same, only the digger had really gone to town here, pulling out the bed and inside point-bar, dumping it all up in the side. The work had been done only a few months ago and already the stream was notching its way back upriver. Already the stream – in other words – was demonstrating the utter futility and pointlessness of the works, because it was now eroding really badly, with the banks slumping in and drastically undercut because of the excessively steepened gradient.

This continued for bend after bend. Apparently as far as we could go and further.

I felt too miserable after a mile or so and we turned back.

Then I remembered the photos I had taken here in 2020, expressly to capture the morphological features of the stream: the meander shapes, the relationship between the water surface and the flood-plain, the gently undercut banks and point-bars. All of which were now screwed. I hunted back on my phone to February 2020 and tried to line up a few before-and-after images. But I struggled to find the correct alignment between the stream and the hills: at least until I realised that not only had they dragged out the bed of the river, they’d tried to cut the meanders out too.

I was still just about thinking it was the farmer’s work and I was trying to fathom the “why?”. I was thinking: “They’ve had massive floods and done all this in an understandable, but misguided effort to drop the river back inside the banks.”

We slumped back to the car and in an effort to cheer both of us up I said to Simon that we’d drive up the valley to another bit I know. Only when we got there Simon looked out the window and said: “They’ve fucked this too. Look at all the gravel!”

And indeed, “they” had. Whoever “they” are.

By now I was thinking: this is the work of a flood defence department. Our own versions did all of this and more in the UK and Ireland. Only flood defence departments are this dim, careless and – I hate to say this but – entitled. I’ve thought about that last word, whether it is justified here, as the first two surely are. And I think it is, because when you go in and radically alter an ecosystem like a spring creek, it is surely beholden on you to understand what you are doing and carry out the works so that they achieve the desired outcome and not simply wanton destruction?

NZ’s spring creeks are globally very special. There just aren’t many rivers like these and most have been messed around with. NZ’s spring creeks have (thus far!) been modified less than most and some not at all. These streams should be seen as a national treasure, not drainage channels.

Later, asking around in town, we discovered that there had indeed been floods. The golf-course had been underwater and so had stream-side houses … miles downriver of the spring-creek vandalism, mind. Riparian property where a river belongs. It all made sense.

Only a flood defence department would steepen the gradient upriver in an attempt to alleviate flooding downriver. Only a flood defence department would make far worse the very problem they were trying to fix.

The river will now try to tear itself apart in order to win back the material it needs to put itself back together. As it does so, the water will travel more quickly, and downstream floods will be more aggressive: they will rise faster and bring with them way more mud, silt and stones.

Rivers flood. The only way to control flooding is to control where it happens. You can’t stop it. Allow it to happen in certain places in an effort to ensure it doesn’t in others. This stream has a two-stage form anyway, with secondary terraces way back from the main channel: you have to let it flood out to these or you will send all the water in even more of a hurry to the very property you are trying to protect.

One optimistic note: this stream will self-heal. Unlike chalk streams, it has the energy and the material to do so. Provided it is left alone. Which is now a very questionable proviso, because the notching and erosion will unleash a process which will appear in the minds of the men who did the work, to justify it in the first place.

And so we struggle on “boats against the current, born back ceaselessly into the past”.

February 2020
January 2023: not quite the same spot but note the new channel to straighten the course, the notching, erosion and bank collapse.
February 2020
January 2020: note the straightening and the height of water against the bank on the r/h of image: maybe 40 cm lower.
February 2020
January 2023: I had trouble lining this one up, until I realised the bright green bit used to be the river, and they had taken the meander out.

More pictures of the destruction:

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