Chalkstreams: reinventing Arcady

With chalkstreams coming under increasing pressure, it’s time to step away from the traditional and manicured and let our rivers breathe writes Charles Rangeley-Wilson

For a host of reasons chalkstreams capture people’s attention and affections. They are globally unique, freshwater marvels, and important habitat to iconic species such as salmon, native crayfish, otters and mayfly. But generally you learn these things after the chalkstream has already caught you in its spell. I fell for them when I was a boy and before I had any idea they were chalkstreams. The creeks of North Norfolk fascinated me with their impossible, blowsy clarity, their gentle hurry, their aura of peace and all the little fish that swam in them, which I failed to catch. (Read our interview with Feargal Sharkey, chalkstream conservationist)

Later, and more consciously, I fell for the chalkstreams in Wessex, where I moved to teach art in 1987. I met the late Richard Slocock, a pioneer of catch-and-release wild trout fishing at a time when many chalkstream fisheries relied heavily on stocking. Richard was a thorn in the side of the water company that over-abstracted his river. And he practised a slightly scruffier, rougher-edged style of riverkeeping than existed on the classic chalkstreams of Hampshire, where the banks were mown hard and weed was cut vigorously and often. Richard became a good friend. I loved escaping to his watery wildernesses to join him on working days, trimming branches and weed, always with an eye to favouring the wild trout over the angler. In return I got to fish his wild river. (Read Charles’s article on the River Usk)

But it wasn’t just the wildness that enthralled me: it was the wildness set within a homely landscape. Those streams flowed through the traces of Hardy’s Wessex, turning mill wheels, chattering through hatch pools and over weirs. The remnants of the many ways that chalkstreams have served us are part of their beauty and the layered archaeology of England: they have been used to protect Anglo-Saxon hill forts; to float stone upriver for the construction of abbeys; to float wool downriver to market towns; to grow hay, grind corn; to water grandiose displays of wealth and status in Palladian ponds and lakes.

This rural industrial heritage certainly took its toll on chalkstreams and their ecology. It is probable, for example, that salmon were shut out of many streams by innumerable mills that were built even before the year 1066. Nevertheless, until the mid-20th century, in spite of all that I describe above, chalkstream wildlife still generally flourished. Chalkstreams were made famous by hatches of insects that are but a memory today. And that is because since 1945 we have really messed them up. We have pumped their aquifers so hard that some streams have dried altogether and many more are ghosts of their former selves. We have filled their aquifers with nitrogen and phosphorus. We have overloaded them with human sewage, too, and with gazillions of tonnes of sediment washed off roads and farmland.

The most widespread damage of all has been through post-war land drainage. With the unlimited horsepower of mechanised excavators we have removed the gravel beds of chalkstreams. Thus a steady slope of clean gravel and chattering flows was transformed into a staircase of silt-filled hollows. The effect of dredging is to take all of the problems I have outlined above, from the relatively benign water meadows to the undeniably malign pollution and abstraction, and to magnify those pressures tenfold. And so the cool, clear, swift-flowing and oxygenated habitat of our chalkstream inheritance became opaque with a fug of algae and silt, bathed in sultry, sluggish, suffocating warmth. All the animals and plants that need the former conditions do not fare well in the latter.

An unsustainable approach

Just before Christmas I was asked to chair a meeting in Hampshire to discuss what to do as the funereal bell tolls on an animal – the chalkstream salmon – that is threatened with extinction, and what to do about improving our two most iconic chalkstreams: the Rivers Test and Itchen. We listened to Southern Water’s plans to invest millions in sewage-treatment upgrades and reducing abstraction. Long overdue, these efforts must be held to account. But sewage and abstraction are not the only issues. What can we as individuals do to make a difference?

This is where, I believe, we must face up to a challenging idea: that the archaeological heritage and our cultural inheritance of river management – features and practices that before the Second World War existed in Arcadian harmony with chalkstreams – are now scratching the itch of other problems, if not making them worse.

Traditional riverkeeping, which is practised in its most faithful form on the banks of the Rivers Test and Itchen, evolved in a prelapsarian world of natural flows, low pollution and undredged riverbeds. It was carried out by knowledgeable countrymen to enhance and gentrify the experience of anglers who wished to fish from the bank. Riparian margins were trimmed just so.

Trees were pruned back and if they fell in they were pulled out. And trout were reared in hatcheries and used to boost the stocks and flatter the angler. This constructed Arcady was beautifully captured in the photographs of EA Barton. It was arguably sustainable before the war, but now? With our streams under such pressure?

Take weed-cutting, for example. Weed has long been cut to prolong its growing cycle and make fishing easier, to ensure that the angler can easily float dry-flies across marbled currents to discriminating trout. In the autumn it was cut to put the river to bed. But it doesn’t actually need to be cut, certainly not where conditions for its growth are favourable. And if it is cut, it doesn’t need to be done so vigorously as often happens. What are the disadvantages? Ranunculus cools the water beneath it, for a start. As the Wessex Rivers Trust long-term temperature record has shown, autumnal average water temperatures in chalkstreams are climbing; September 2023’s temperatures were the highest they have recorded. Ranunculus also helps to maintain water velocities as flows diminish. Taking a more measured approach to the weed-cut might be good for salmonids, especially young salmon.

Feeding the problem

Certainly, focusing on what Ranunculus needs to thrive might be a better use of time and energy. Ranunculus grows best where there is a natural gradient, strong flow and an undamaged bed of gravel. It grows precariously where the bed has been damaged and is soft and silty. It doesn’t grow at all where the water is sluggish. An excess of nutrients complicates things: too much phosphorus and nitrogen and Ranunculus responds with superabundant surface growth, fatally allied with shallow, weak roots. This makes it excessively dominant but susceptible to becoming ripped out by winter floods. Thus the trinity of modern pressures – nutrient pollution, abstraction and habitat damage – have ramped up in post-war years to make Ranunculus either super abundant or absent one year after the other. Routinely cutting it in a manner that disturbs silt and reanimates nutrients is arguably feeding the problem. Especially if that work is combined with using all the old milling and water-meadow structures in the river to hold up flows and create more benign conditions for stock fish.

And what about those stock fish? It is definitely true that in some settings trout fisheries would be hard to sustain without stocking. However, back in the Edenic days of the early 20th century wild fish were abundant and stock fish only ever a modestly sized addition. Later, after the war, stocking practices increased in direct response to environmental pressures. As wild fish suffered, so stock fish were increasingly relied upon to provide sport. Now, some places are addicted to the drug of abundant, large fish. Again, it’s a catch-22. Hatchery fish stocked in large numbers and at unnatural sizes behave like scaly hooligans. They sap energy from wild fish that are forced to defend their territories. And now that we must only stock with triploids that cannot breed (a good idea in a way) they overwinter well and exert a greater predatory toll on young wild fish, trout and young salmon included (thus a bad idea in another way).

And what about the pruning, trimming and mowing: the domestication of spaces that we expect wild animals to occupy? Isn’t it strange how the best fish lie in the most impossible places? Deep under trees where you can’t land a fly? The temptation is to remove that tree so that a fly can be cast. Only then, of course, the fish is gone. So, we stock one instead. Wild animals so obviously abjure the tidy hand and mind of man and yet we, daft as we are, ceaselessly tidy around them in an effort to catch them.

Not only is untidiness good for fish, it is good for everything. Chalkstream channels were formed by fluvial processes that have long since retreated from our landscape. Lacking the energy now significantly to reshape their inherited form, chalkstreams rely on a symbiotic relationship between the flowing water, the habitat it creates and the fish, mammals, plants and trees that habitat is home to, which in turn shape the dynamic stream and keep it healthy. Fallen trees, above all, are grist to the chalkstream’s ecological mill. They give it structure and energy, scouring pools, moving gravel. For decades we have dragged out trees the moment they fall, on spurious grounds of flood protection. But a tidied chalkstream is systematically robbed of the primal sources of the energy on which its life depends.

Release the shackles

Chalkstreams have been so profoundly altered over the centuries. Their ice-age inheritance of meandering, gravelly channels has been diverted, canalised and dredged beyond recognition. Mile after mile now flow in man-made canals along the edges of floodplains, falling in steps over mills and weirs. The rural, industrial legacy, though attractive in many ways, is now obsolete. In a world where chalkstreams are under such pressure, is it not high time we released them from their anthropogenic shackles? I have seen the astonishing transformation that takes place when you give back to a chalkstream its natural gradient, its meander pattern and, crucially, its riverbed. Suddenly the river can breathe and wildlife rebounds.

Happily, more and more landowners and farmers are looking at their inheritances and wanting to do things differently. It’s high time we upped our ambition for these rivers and let them out of jail. Apart from anything else, for our chalkstream salmon it may prove to be the lifeline they need. (Read our recipes for chalkstream trout here.)