Читать книгу Life of a Chalkstream - Simon Cooper - Страница 9
ОглавлениеAS EVER, MY ancient leaking Land Rover provided little protection against the sideways rain of the late October day as I drove down the potholed track to the river. I had hoped for better weather. This was to be a landmark day in the restoration of Gavelwood: our first step towards the re-creation of something special, where the fruits of our dreams and expectations would, at least in part, be rewarded. After a month of back-breaking work North Stream was ready to be opened to fresh, gin-clear, chalkstream water from the Evitt for the first time in four generations.
North Stream is an ancient carrier that connects the main river – the Evitt – with another side stream we call Katherine’s Brook. I say ‘connects’ in the loosest possible sense, because barely a drop of water has flowed through it in living memory. Along its entire length – about half a mile – it should really be a fast-flowing little river that takes the excess flow from the main river into Katherine’s Brook, which in turn will rejoin the main river some 3 miles downstream. Instead the stream was a morass of fallen trees, roots, bushes, debris and mud.
I parked up close to the junction of the main river, where there is a set of hatches, built long ago, to control the flow of water into North Stream. Back in July, when we had first conceived the restoration plan, those hatches were almost invisible. On the river side a thick margin of reeds had choked what would have been the funnel-shaped entrance to the river. Today, the weeks of work had revealed three upright pillars of limestone, about the size of a tall man, set into the bank. They are slightly pockmarked in places, but generally washed smooth by centuries of water. The fronts of the pillars are V-shaped to deflect the current, and running down each inside edge is a groove into which are slotted oak boards – these regulate the amount of water that flows from the main river into North Stream. The oak is newly sawn, a lovely bright honey yellow that would, in a few months, turn to a silver grey. But for now their newness is proof that the hatches are repaired and ready to play their part in the rebirth of North Stream.
With everything Gavelwood has to offer – miles of main river, side streams and hundreds of acres of water meadows – North Stream might seem an unlikely candidate for the first step in the restoration. At first glance, if you noticed it at all, it looks marginal. It is not very wide – a reasonably agile person with a short run-up could leap it in most places – and is fairly straight, without any particular features that catch the eye. My suspicion is that given a few more years it would have disappeared entirely to become a soggy ribbon across a water meadow, its original purpose long forgotten. But the first time I saw it I knew it had the potential to become the most wonderful spawning stream for trout, salmon and maybe even grayling.
On that first visit as I walked down the bank, occasionally pushing aside the branches of the bushes and trees that choked the channel, a few small, bright pockets of gravel glinted back at me, lit by the rays of sunshine that cut through the gaps in the foliage; the gravel kept free from silt by the spring heads that bubbled up from deep below. Loose, well-oxygenated gravel is vital for spawning trout. It is the place the gravid female lays her eggs and the home for the ova as they metamorphose from eggs to tiny fry, out of sight from the many predators that see them as a nutritious food source. My hunch was that beneath the silt and overgrowth North Stream was a gravel haven and finding out was not going to be very difficult.
In fact it proved harder than I thought. A combination of wicked stinging nettles that are at their fiercest in the high summer, plus the barbs of the hawthorn and the clawing tendrils of the wild roses forced me back each time I tried to push my way down the bank. Eventually I came across an ash tree that had fallen across the river, flattening my access. Using a tree branch for support I slowly lowered one foot into the shallow water, letting my weight push it down through the thick mud, hoping that I would make contact with the riverbed before the water reached the top of my boots. Fortunately I did, and the firm base beneath my boots told me I had reached the best kind of rock bottom. I jiggled my feet and through the thick rubber soles I could feel the friable gravel. As I waded upstream I kicked away at the silt bottom to expose what I had hoped for – gravel the entire length of the stream. The further I waded up the more certain I became of the plan to have North Stream ready for autumn spawning – with clean, bright gravel where the trout eggs would be nurtured by a constant flow of fresh water from the main river. Yes, the timetable was tight and yes, the work would be hard, but at that moment to miss yet another year, after the decades of decline, seemed positively criminal.
I plotted the timetable as I walked. We needed to be finished by 1 November. River Evitt trout typically start the act of spawning around mid-December, but they would need at least a month to grow familiar with their new environment before beginning courtship. To have us clumping around would put an end to that before it even started. The trout fishing season ends on 30 September. It would be tempting to start clearing the stream earlier, but our downstream neighbours, not to mention our own anglers, who regularly fished at Gavelwood, would not thank me for sending muddy water and debris their way. So we had four weeks to take what looked like a clogged ditch and transform it into a piscatorial love nest and nursery.
There are two ways to restore a river: the easy but expensive and the cheaper but hard. The easy but expensive way involves signing up an ecological consultant who will start by carrying out a painstaking survey (at your cost) of the river and surrounding land. Every tree will be plotted, the curvature of each bend delineated and the depth of the pools plumbed. Soil and water samples will be analysed, flow rates monitored and the wildlife censused. In return for a mighty fee you will receive a mighty document with maps, drawings, graphs, commentary and appendices. You’ll read it. Actually you won’t – you will read the two-page executive summary at the front and glance through the rest. Fortunately your fee includes a presentation, so you head for the consultancy offices. Having been ushered into the boardroom by a receptionist you are then glad-handed by the team. Everything is very exciting and the possibilities immense. You can only agree, but how do I do it, you ask. At this point the meeting gets serious. Sitting across the table from you is the Chief Executive, who takes a copy of the report and places it squarely on the table in front of you.
‘May I be frank with you, Mr Cooper?’
My advice to you at this point is to say no and leave; no good can ever come with a person who opens with this line. But you are curious, so you invite the man to continue. He opens by telling you what you know already. The report on the table is the perfect guide to do-it-yourself restoration. Everyone around the table knows this, but our wily Chief Executive casts a fly into your path he knows you will take.
‘How much were you planning to spend on the project?’ he asks innocently. You quote a number, faintly embarrassed that you thought it could be done for so little. He purses his lips. ‘Here’s the thing,’ he says. ‘You will do an OK job with that budget, but this is such a very exciting project, the potential so immense, that we should think big. Let’s quadruple your budget, apply for funding, and in the end you’ll only have to dip into your own pocket for a fraction of what you originally thought.’
The lure of his fly is too much and you rise to it like the greedy chap you are. The thought of twenty grand’s worth of work for the cost of five is too much to resist. Leaving the room an hour later you have been truly hooked and landed. The consultants are delighted (but not surprised) with a new contract to seek out funding and manage the project when the grants roll in. You are of course still on the hook for their fees if the funding never shows up, but that is a discussion left for another day.
But I don’t much like easy and expensive. It takes too long, the finished job is never as good, and it seems a bit immoral to me that half the money will go to consultants, however expert. And quite frankly, where is the fun in handing the project over to strangers? I wanted to get my hands dirty: stand in the river, look upstream and with a trout’s-eye view of the world fine-tune the work as I went along.
But all this was still ahead of us when my team and I gathered in August to make plans for North Stream’s restoration. It was not the best month to do our kind of survey – the undergrowth at its most dense, the flow almost non-existent – but we could see enough to make some educated guesses. The work was going to be done by Steve, Dan, myself and a team of irregular helpers.
Steve is the closest thing we have to a full-time river keeper. A retired fireman who looks forty but is in fact fifty-five, he runs triathlons just for the hell of it. He can, and does, work all day felling trees, cutting weed and hammering in fence posts. He is in fact more of a coarse angler, and Gavelwood sort of inherited him when some local lakes closed down.
Dan is young. We tease him for being young and he mocks us for being old. In his early twenties, Dan is on a sabbatical year from his university ecology course. I have a feeling he may have dropped out for good, but it is a suspicion I have kept to myself.
The irregulars are a band of loyal fishermen and locals who simply like to help. They turn up as they wish, or Steve will put out a call when he needs some extra hands. It seems to work and every few months I put some cash behind the bar at the pub for an evening of merriment. Work on the river next day is sparsely attended.
On that particular August morning Steve, Dan and I had gathered at Bailey Bridge, a steel latticework bridge of the same name that was invented by the British army. You used to see them all over the river valleys at one time, but most have rotted and rusted away. Built of light steel and wood, in sections small enough to be lifted into place by hand, they were ideal for bridging meadow streams. Designed to take the weight of a tank, they were much loved by farmers, not least because they were easy to ‘liberate’ from the nearby military camps on Salisbury Plain if you drank with a friendly sergeant major.
Our bridge looked to me like it was getting towards the end of its life, but we estimated that by replacing a few of the wooden boards and repainting the metalwork we could eke a few more years out of it. I had my doubts about its inherent strength but Steve was prepared to test it out by the simple act of driving a tractor and laden trailer over it. Sometimes he worries me.
The first decision we needed to make was whether to clear one or both banks along North Stream. Both sides were equally overgrown, and there are merits whichever way you choose to go. In sheer practical terms opting for a single-bank restoration halves not just the work required for the initial clearance but also regular maintenance in the years to come. With our tight timetable it was an attractive proposition, but ultimately we had to decide on what was best for the wildlife, the river and the fishing.
Stepping off Bailey Bridge and towards the stream, our path was blocked by chest-high stinging nettles. Nettles are no great friends of ours – sure, they are much loved by caterpillars, who feed voraciously on them, but for the river keeper and angler they are a menace. They grow fast, crowd out more useful bankside plants and sting like crazy. Fortunately getting rid of them is not hard, at least if you have someone like Dan to do the work. Nettles are nitrogen addicts – in their effort to run wild they suck every last drop of nutrient out of the ground. But when they die back in the autumn the rotting stems and leaves put nitrogen back into the soil ready for next year. However, cut the nettles down and rake away the cuttings and you deprive the next generation of their nitrogen fix. Other species soon encroach on the ground left bare and new plants thrive in place of the nettles. For Dan a couple of weeks with a scythe and rake were on the cards.
Beyond the nettles and bordering the stream was the scrubby woodland that ran the length of North Stream. On both banks it was 10–15 yards wide, because some years earlier it had been fenced off. The fence was pretty much all but gone, save for a few posts and rusting strands of barbed wire that would no doubt trip us up at some point. The main growth was really stunted hawthorn, which had done us something of a favour in the absence of the fence, by keeping the cattle away from the banks and out of the river. Pretty in its own way, and home to the hawthorn fly, we mulled over how many of these bushes-cum-trees should stay, be trimmed or cut down. I am a huge fan of hawthorn. It is the constituent element of every hedge in the chalk valleys and in April its vivid lime-green leaves and white or red flowers are the first tangible proof of spring’s arrival. Admittedly the flowering bushes do emit the most awful stench, which makes you think there is a rotting corpse under every hedgerow, but once you know what it is it does not seem that bad.
What’s more, the hawthorn fly or St Mark’s fly (Bibio marci, so called because it hatches around St Mark’s Day on 25 April) causes much excitement among fly-fishermen in the first few weeks of the season, not least because trout go on quite the feeding frenzy when these clumsy fliers drop onto the river surface. The fly has no real connection with the river, so why trout go mad for these freakish-looking creatures is a mystery about which one can only hazard a guess. At first glance the hawthorn fly looks like an athletic housefly, but at second you’ll see its long spindly legs dangling below it, like the undercarriage of an aircraft, with big knuckles for knees and so hairy you might even stroke them. The flies don’t live for long, maybe a week at most, having emerged from larvae in the soil beneath the hawthorn bushes. Once hatched they hug the hedgerows for protection from the wind, but from time to time an unexpected gust will whisk them across the meadows. From this point on things get tricky. They are, without shelter, the most hopeless fliers and you will see them buffeted by the breeze. Occasionally when the wind drops they regain control, but it will be short-lived and once over water they will plop onto the surface. Unable to break free of the surface tension they are easy pickings for the trout.
Along the length of North Stream and among the hawthorn are a few spindly ash, plus some alders, clumps of hazel, brambles and wild roses. The trees we wanted to keep we marked green, those we would thin, blue, and the rest – marked red – were to be cleared. It soon grew abundantly obvious that on this bank there was not much to preserve, whilst on the opposite side pretty well everything, bar a few branches that were falling into the river, could remain undisturbed as a sanctuary for the creatures that live along the riverbank.
Part of the restoration process is about letting light back into the river and onto the riverbed itself so that the weed there can grow. The term weed does these river plants like crowfoot, starwort and water celery something of a disservice. Weed implies that they are invasive and bad, but the reverse is true. The right river weed, in the right river, is home to nymphs, snails and all manner of tiny aquatic creatures. It provides cover for fish, shade from the sun and refuge from predators. And as a filter for the water, a healthy river needs healthy weed, and that will only grow with sunlight. It is hard to say anything bad about weed, and a chalkstream without it is on a downward spiral.
Removing a fair amount of the thicket growth along the south-facing bank was going to suit us very well. In this respect clearing the north bank alone would not have helped, because as the sun tracks east to west across the sky during the day it would have left the stream perpetually in shade. If you ever doubt how bad perpetual darkness is for the ecosystem of a river, glance under a bridge one day; it will be as bleak as the surface of the moon. That said, our work was far from about eliminating all shade; trout and all the creatures thrive best where there is a mix of light and dappled shade, so before we took the saw to any bush or tree we cocked our heads to each in turn to decide stay, trim or go.
All the way up North Stream the stream itself was no great issue for us. Sure there were plenty of branches and stumps to pull out, but the dark shade had pretty well prevented anything growing. Once the obstructions were removed the sheer volume of water over the winter would flush away the mud and slime. That was of course always assuming we were able to open up the Portland hatches.
Removing the decades of compacted silt could be done by hand but it would be long and laborious, so we elected to bring in a digger to do the job. Machines are great, but sometimes you have to go easy with them or risk doing damage to the very things you wish to preserve. The Portland hatches were a case in point. They had stood the test of around 500 years because they had been carefully constructed with strong foundations. Smash those with the digger bucket and our problems would multiply.
Steve produced a steel rod with a T-bar handle. Jumping down onto the silt he pushed the rod into the ground until at around 5 foot down we heard a muffled clunk. He tapped the rod up and down twice to confirm that he had hit something solid. Over the next hour, working like an avalanche rescue team on snow, we each took a rod, gradually mapping out the depth and extent of the stone slabs ready for the digger to do the hard graft once the season had closed.
There is never what I would call a really good time to embark on a restoration; every month, every time of year has its merits, but inevitably there is disruption to the natural order of things – removing the bad and encouraging the good. The bad comes in all shapes and sizes: people, fish, animals, mammals and even plants. Yes, there are even bad plants on the chalkstreams, the most invidious of which has its origins on the foothills of the Himalayas.
My problem with Himalayan balsam is that I rather like it. The tall plants stand high above the surrounding vegetation in vast swathes and the light red-pink funnel flowers are a sea of colour that gently waves in the late summer breeze. The smell from the flowers envelops the riverbank. It is a dry, sweet smell – lightly medicinal and cathartic at the same time. It is completely alien to anything else that grows in the meadows. It looks different, smells different and has the most amazing way of distributing seeds when the flowers have died and the tall plants are denuded of leaves, just leaving brown seed pods. Brush past the balsam and the seed pods burst with an audible ‘pop’, shooting their kernels yards around. It happens with quite some force; you will feel the sting if they bounce off your face or hands. Young children love to grasp the plant at the base, shaking it with all their might while the rat-a-tat of seeds sails harmlessly above them.
Imported as an exotic species from Nepal in the early 1800s, Himalayan balsam is now established in Britain, but has had particular success on rivers where the seeds, which can survive two years, are distributed by the water. As a single plant it is no great problem, but that is not in the nature of Himalayan balsam. It is an invader that grows faster than any native plants, shading out and eventually killing all others. Walk the banks in October where the balsam has taken hold, and the area looks like a wasteland. Everything beneath the balsam is dead. In truth it looks like the ground has been sprayed with a toxic weedkiller, and come winter, that soil is bare and ripe to be washed into the river.
Fortunately for me and river keepers everywhere, Himalayan balsam is an enemy that can be defeated. For now, in October, there is not much I can do, but come early summer when the balsam pops its heads above the surrounding growth we will walk through the meadows pulling out the plants by hand. Mercifully they are shallow-rooted, so they come out easily or snap off at the base like soggy celery. However, not all my enemies are so easily defeated.
Mink have thrived in the abandoned Gavelwood. Wily creatures, the thick undergrowth and clogged streams are heaven-sent for this predatory invader. Predatory they certainly are. Fish, water voles, field mice, duck chicks, frogs, baby moorhens, even rabbits – if it moves mink will eat it. The mink I see at Gavelwood are American mink – Neovison vison – which first arrived about a century ago as escapees from the fur farms that were established between the world wars. Despite their fearsome reputation they are really quite cute; I always think they look like a bigger, elongated version of their favourite prey, the water vole. Mink have the most beautiful dark brown fur, almost black in some light. Strangely, though all the mink you spot today are this colour, they all originated from the light-coloured mink imported by the fur trade. Clearly, however, being white in green meadows was a poor lifestyle choice. After a century of wild living it is a moot point as to whether mink can still be regarded as an invader. Non-native definitely; indigenous never; but successful settlers yes. They took hold at precisely the same time that the otters declined. It was no fault of the mink that the otter almost became extinct in Britain, but nature abhors a vacuum.
On that filthy late October day the success of our survey and the work Steve had done with the digger was there to see. The silt and mud were gone, smeared over the grassland around the hatches. The wet surface of the slabs on the base of the river glinted back at me. Some of them were truly huge; a full 10 feet square and nearly a foot thick. One could only wonder at how they were ever put into position all those centuries ago. The digger stood by ready to drag out the reeds within the hour.
I wasn’t exactly sure where Steve, Dan and the irregulars were working that morning, but the whine of the chainsaw through the rain from somewhere far downstream gave me a rough idea, so I followed the noise. For all our hard work over the past month North Stream really looked in quite a sorry state. I am tempted to say worse than when we had started, but it is always this way, a sort of darkness before the dawn.
The ground along the bank was churned up; deep ruts showed where the tractor had strained and dug deep to pull out the worst of the trees. Every so often I would come across a round circle of ash where the lads had lit fires to burn up the detritus. There was a pile of tree stumps, too big to burn and unwieldy to cut up, so they would be taken away to be dumped and end their lives in a rotting heap. This would be a paradise for woodpeckers seeking easy food and a palatial home for woodlice. From time to time I came across some long, straight tree limbs which had been carefully trimmed and set aside. This was our kind of recycling; logs and branches that would be useful for building weirs, flow deflectors and groynes in the river when we reached the next stage of the restoration.
The entire bank was pockmarked by tree stumps, cut level with the ground: the cream white of the ash; dark red of the alder and burnt orange of the hawthorn. The hazels looked like bundles of cigarette filters pushed into the ground. The fact is we only pulled out the stumps we had to; by far the most were left in the ground. There is no point in ripping them out, as the root structure will live for years and bind the bank together. Some of the stumps will sprout again, indeed species like the alder thrive as a result of the extreme pruning. And as North Stream evolves over the coming years, we’ll let some grow back into mature trees for cover, shade or simply extra interest.
If I thought the banks looked bad, the stream itself looked worse. The water reflected the sky; it was dark and gloomy. Barely flowing, the surface was covered in twigs, chainsaw shavings, dead leaves and chopped vegetation. On the far bank the bushes and trees had shed all their leaves, the spindly branches dripping from the rain. The only comfort I took was in the windbreak they provided from the north wind whipping the rain across the meadows. A north wind is the enemy of all fly-fishers – the cold kills off hatch and stops the fish feeding, which gives rise to that old saw, ‘When the wind is from the north only the foolish angler sets forth.’ However, today was not the day to worry about the north wind, which is an almost daily occurrence in winter, sweeping as it does down the river valley. Days like this are always the fun parts of a restoration, when months of planning and weeks of work come to fruition. Today all we needed to do was dig out the plug of reeds, lift the boards in the Portland hatches and let the river flow in. And that is what we did.
Steve used the digger to scoop out the reeds and we laid them to one side. The flag irises, with their yellow flowers that bloom in May and June, were too beautiful to discard, so we’d replant the rhizome roots down North Stream to kick-start the regrowth in the spring in the parts of the stream left bare by their removal. The reeds gone, the water started to build up against the honey-yellow oak boards. These boards are never completely watertight; water weeps through the gaps between them. So as the flow backed up and the pressure increased, water squirted through the holes as if from a hosepipe. We were ready to open up. Standing on the bridge boards over the hatches we worked in pairs to lift the top boards out. The lower four quickly followed and within moments the fast flow from the Evitt rushed into North Stream. Like excited schoolboys we followed the bulge of water as it forced its way downstream. From time to time it came across an obstruction. Then the water would begin to back up, but when the force grew too strong the obstruction would give way and the flow continued. On it went down North Stream, carrying the mud and debris in its path. Under Bailey Bridge and the final straight to the main river. Standing by the deflector we watched the confluence of the two currents, the first time anyone had seen this for maybe forty or fifty years. True it wasn’t the prettiest of sights, with the dirty water of North Stream adding a nasty stain to the clarity of the Evitt, but the knowledge that our plan had worked was enough for now. Given a few weeks North Stream would flush itself clean, and then the fish would return.
