Taming the Flood: Rivers, Wetlands and the Centuries-Old Battle Against Flooding

The new Catchment Boards’ first decade of river clearance was followed by the outbreak of war, during which Parliament empowered the boards to carry out even more extensive work at the request of county war agricultural executive committees. Government offered a 50 per cent grant for such work, which remained in force after the war. In 1951 the Heneage Report recommended that the length of ‘main river’ to be cleared by river boards be trebled, thus extending their jurisdiction to over 12,000 miles of river. For those who have eyes to see, the legacy of all this activity, rigorously maintained, and in some cases extended by water authorities in the 1970s and 1980s, is a river system in the lowlands of England and Wales which is profoundly impoverished. If the traveller looks out of the car or train window or takes a walk along the local brook and bears in mind what a river should look like, they cannot fail to notice, in many places, mile upon mile of treeless river bank, often devoid of even a decent margin of bulrush. A survey of the middle reaches of the river Idle in Nottinghamshire in 1980 discovered two clumps of marginal plants and three trees over five miles of river. In the late 1930s the Sussex Rother was subjected to total clearance at Bodiam. The scars remain. The Staffordshire Blithe, whose lower reaches escaped the axe and are therefore witness to how exquisite a properly managed river can be, was picked out for special mention in the Journal of Agriculture for 1927. Its upper reaches remain bare, and are eroding rapidly.

FLOODS AND WAR

This policy of river clearance was originally supported by two fundamental considerations. When war broke out in 1939, the combination of a depressed agriculture at home and a convenient empire abroad had ensured that around 70 per cent of the nation’s food was imported from overseas. Hitler’s U-boat campaign, the memory of which still haunts decision-makers in the English countryside, nearly succeeded in blockading our coast. Despite rationing and a vigorous ‘Dig for Victory’ – not to mention ‘Drain for Victory’ – campaign, the people of Britain were in danger of starving. Supplies of food ran sufficiently low to pose a threat as serious as invasion. It was with this in mind that a unanimous Parliament supported not a conspiracy of Tory landowners, but Attlee’s post-war Labour Government in passing the 1947 Agriculture Act, which laid the foundations for the great agricultural revolution of our times. By 1973, when Britain entered the Common Market under the shadow of increasing anxiety to improve our balance of payments, Attlee’s policy of farm protection had been extended by a massive subsidy of capital grants, tax concessions, and price supports; and the impact on the landscape, including the river systems, was really beginning to bite. Significantly, the same Parliament that passed the 1947 Agriculture Act also brought into being the 1947 Town and Country Planning Act, thus creating the planning system that, to this day, regulates all aspects of British life except agriculture and forestry, which remain largely exempt.

In the black winter of early 1947, something else happened which was to provide a general justification for the next forty years of dredging and river clearance. On the night of 16 March, waters from melting snow began to burst the flood-banks in the Fens. Wentworth-Day, who lived through it all, describes the experience:

Throughout the black night came the dull thunder of the bursting banks, the village alarm of ‘she’ve blowed’. The river is always feminine. In a thousand remote little farmhouses and cottages, islanded beneath wind-shriven willows or leaning poplars, the racing floods covered the black fields, overflowed the straight dykes … and leaping upon those lonely homes with all the relentless force of wind and gales, burst open the doors, shattered the ground floor windows … and rushed gurgling and swirling up the narrow staircase.

In the freezing cold and pitch dark, families were driven to clinging to the roof. In the south level 37,000 acres went under water, and the chief engineer of the Great Ouse catchment board considered it the worst fen flood since the time of Vermuyden.

Disasters of this sort were confined to neither traditionally flooded land nor the winter months. In August 1952 the innocent-looking East and West Lyn rivers swept down into the Devon resort of Lynmouth, obliterating houses and removing all trace of the Beach Hotel, which was carried out to sea.

Thirty-three people were drowned, and the main street was transformed overnight into a dramatically boulder-strewn river bed. This flood, in a narrow valley, exacerbated, it was thought, by trees blocking the bridges upstream, was different in kind from the inundation of large areas of low-lying land in East Anglia. It helped set in motion renewed enthusiasm for tree clearance in upland catchment areas as yet another aspect of the land drainage solution.

The following February, floods again struck the east coast, from Northumberland to Kent. The casualty list was 307, and the devastation immense. On Canvey Island alone, 11,000 people were rendered homeless.

Coronation Day, in June 1953, was a memorably wet day. While the symbols of civilization processed with full panoply of State through the streets of London, out on the eastern marshes the North Sea nudged at the coastal defences which had been hastily shored up after the calamity just four months before. Our era was ushered in with a reminder that the flood remained not entirely tamed.

The twist in the story of river and wetland management in our own times was to be one in which drainage engineers were faced with a new army; an army which, unlike that of the commoners who had opposed their predecessors, was to grow stronger with every passing year. It was to come from an unexpected quarter: the environmentalists. Just as the drainers had previously arrived as outsiders on the wetland commons, so the conservationists were to wade into the wetland issue, often importing their perspectives from outside. All this was foreshadowed at the height of the war and in the heart of the Fens by the testimonies of two passionate and knowledgeable countrymen, one a bird-watcher, the other a farmer. Their conflicting attitudes to Adventurers’ Fen, which the one painted and the other drained, are both completely understandable in human terms.

In 1942 Eric Ennion wrote Adventurers Fen, celebrating its birdlife and the haunting beauty of its landscape. His celebration was also a requiem. He wrote:

The power of a flood. A house collapses under the impact of water in the 1953 east-coast disaster. © HMSO

It is more than a year since the red and white surveyors’ poles glinted above the reeds, blazing a trail for the draglines that were soon to follow. They came, each with a gaunt arm cutting the gentle skyline, clanking and threatening, laying their tracks as they rumbled along … In a few short weeks the scoops had torn a channel twenty feet wide from end to end, ripping the backbone out of Adventurers’ Fen … When all was dry, men set the fen on fire. Spurts of flame began to flicker here and there and presently leapt up to redden the fringes of the great smoke cloud which hung above them … Reed beds, sedges and sallows vanished in a whirl of flying ashes amid the crackle and the roar.

I went down afterwards. There was a single gull wheeling over the black land and a wild duck trying to hide in two inches of water at the bottom of a drain. A couple of tractors stood waiting to begin.

Alan Bloom, who had helped implement the scene described by Ennion, and was unusual in being both a practical man and a writer, published The Farm in the Fen in 1944. He conveys with a sure sense of atmosphere and detail the satisfaction of getting a job done, the feeling of being within a tradition of a long line of settlers of the land, and the sheer hard work that entails: from persuading recalcitrant committees to support his endeavours to the literally back-breaking labour of dragging obstinate lumps of bog oak out of the peat to facilitate ploughing. One morning, Bloom records, after ‘a particularly bitter struggle with an oak’, a Cambridge student came wheeling his bicycle up the drove-way. The young academic coolly eyed the embattled farmer and, commenting upon the destruction wrought upon the fen, looked forward to its return to wilderness after the war, so that it could act as a buffer for the nature reserve of Wicken Fen against the farmed land:

Against the farmed land, be damned, I thought, and let drive with all the most forceful arguments I could lay my tongue to. But I might have spared myself. When I had finished I could see that it had made not the slightest impression. We were in opposite camps, and he could no more appreciate my line of reasoning than I could see his point of view, and finally we parted.

Bog oak, the relic of wartime battles to drain Wicken Fen, remains stacked among the nettles in a corner of the fen.

‘A wild duck trying to hide in two inches of water at the bottom of a drain’, Eric Ennion, Adventurers Fen.

This conflict of values in which neither side has an absolute monopoly of truth has rumbled on, becoming louder and louder in the English countryside. In the latest episode, rivers and wetlands have often been the field of battle. The story of this conflict forms the subject matter of the remaining chapters of this book.

CHAPTER 4 (#ulink_a181c352-ece6-5101-aa57-246f81e21e15)

THE WASTING OF THE WATERS (#ulink_a181c352-ece6-5101-aa57-246f81e21e15)

The Real Cost of Orthodox River Management

In 1977 the Ministry of Agriculture estimated that 6.4 million acres of agricultural land in England and Wales needed drainage.

This, approximately one-fifth of the nation’s farmland, was expected to keep engineers in the newly formed water authorities fully occupied until well into the next century. In 1980–1, a fairly typical year, the grant from the Ministry of Agriculture for land-drainage schemes, including some urban work, amounted to about £30.5 million, of which £23.7 million was allocated to the water authorities, while the rest went to internal drainage boards and local authorities.

In that year it is estimated that the water authorities spent around £40 million on capital drainage schemes for agriculture. In addition, all water authorities spent large sums on routine river maintenance on farmland; and still more money was spent by the Ministry of Agriculture in contributing between 30 and 70 per cent of the cost of farmers’ field drainage, designed to pick up the benefits of lowering the water level, a result of river engineering schemes.

AGRICULTURAL REASONS FOR DRAINAGE

Much of this expenditure, which has taken such a toll on both the exchequer and the environment, has been based on a simple assumption that is deeply embedded in agricultural thinking: that excess water is the enemy of good husbandry and must be driven off the land. In those places where stock is kept out in winter, undrained grassland is unusable during floods, and in summer is susceptible to trampling by animals, and so supports less stock than drained pasture. In addition, damp conditions encourage husk in cattle and fluke in sheep. For the cereal farmer, wet land is late land, since waterlogging keeps the ground cold and holds back germination. Saturated soil lacks air, without which plant roots die, helpful micro-organisms are checked, and the soil loses its structure. Roots of wheat which have been stunted by excessive water in spring will be less able to withstand a summer drought. Actual flooding can be disastrous. Depending on the time of a flood, root crops can be completely destroyed if submerged for more than twenty-four hours.

AGRICULTURAL OVER-PRODUCTION

The real problems that undrained land presents to farmers have justified drainage during periods when we have been short of food. What is now questionable is the national need to produce a maximum, perfect crop on every piece of English farmland. The process whereby rivers have been straightened and lowered to allow all riverside land to be more intensively cropped for grass and grain has often been expensive in terms of both wasted investment and loss of landscape. The environmental cost has been the destruction of wetlands and the general erosion of the rural landscape, whereby hedges, woods, and ponds have been removed. The habitats that have been hardest hit by the post-war agricultural revolution are on land that was always regarded as the most marginal: the barest hilltops, the steepest hillsides, and the wettest valley bottoms. The reason why these had survived so long was because they required the most money spent on them – in the case of valley bottoms, to pay for initial drainage and then to maintain it – to make them yield their full potential of arable and pasture. Now, with the massive harvests of the 1980s, when the superabundant corn bows its head along the banks of our chastened, canalized rivers, many of those who set out to tame the flood have succeeded beyond their wildest dreams. All over Europe there lingers the sweet smell of excess. In the south of the Continent, piles of surplus peaches and tomatoes are bulldozed, and cauliflowers are mixed with cod-liver oil before being buried. In the north, agricultural officials no longer discuss whether the harvest was adequate, only how the latest addition to the grain mountain can be stored. In 1985, as reported in The Times, the cost of simply storing the United Kingdom’s cereal surplus amounted to around £111 million. That same year, the agriculture commissioner for the Common Market revealed a new solution for reducing the butter mountain: feeding it back to the cows.

With the massive harvests of the 1980s, cereal crops bow their heads over our chastened and canalized rivers.

Such is the latest outcome of forty years of enthusiastic and single-minded agriculture, of which an equally enthusiastic drainage policy has been an essential part, that conservationists are now questioning the aims of intensive river management on its own terms of hard-headed economics and efficiency. The wetlands, long regarded as wastes by generations of farmers, have been replaced by a harvest which fits the dictionary definition of ‘waste’ in every sense. Our annual surplus of grain is roughly equivalent to the annual yield of the Cambridgeshire fens, won from the flood by Cornelius Vermuyden 300 years ago. Intensive cultivation and continued drainage of the Fens further accelerate the degradation of the land, which is increasingly subject to peat wastage through oxidation and windblow.

Recently there have been determined efforts to reduce our food surpluses, but we are only starting to learn that river and land management require careful thought before instant expenditure of money. The drain-all, strip-out approach to land has been adopted by insurance firms investing in agriculture precisely because it requires no more thought than it takes to fill in a form for the subsidy. The practical reason it is wise in the long term to give much more careful thought to river and wetland management is that drainage can contain, profoundly, the seeds of its own destruction.

PHYSICAL DESTRUCTION FROM RIVER ENGINEERING

The real cost of river mismanagement can begin with engineering works on the watercourse itself. As many of the old river managers learned from first-hand experience of tinkering with their rivers, it is ultimately far more productive to work with a river than against it. It is the nature of rivers that they refuse to stay straight. ‘It’s always twisted,’ said a seasoned riverman of the Shropshire Rea, ‘and it always will.’ Cage a river in cement and iron, and it will struggle to break out like a wild beast. Major straightening of the Mississippi in the 1930s, largely for navigation purposes, is still creating problems for its present-day managers over hundreds of miles. Attempts to straighten out the Lang Lang river in Australia between 1920 and 1923 caused a series of cuts into the bank, which progressed rapidly upstream and destroyed seven bridges.

But it is not necessary to look so far afield or so long ago for examples of rivers which have refused to obey the dictates of engineers. In 1864 the river Ystwyth in Wales was straightened to run parallel to a railway track. In 1969 it was back again on its wandering course, and was engineered cheaply back into line by dredging out the gravel shoals which were causing it to wander. However, this did not turn out to be such a cheap solution in the long run, since it set up conditions of even greater instability, necessitating repeated operations every two years.

Major work on the river Taff and the river Usk in South Wales, carried out in the early 1980s, has precipitated extensive and unforeseen repair bills. Those who win money on the horses at Kirkby Lonsdale races in Cumbria can quickly sober up if they wander down from the racecourse to see how their rates have been spent on the adjacent reaches of the river Lune, where the recently cemented banks are dramatically caving in, and attempts at bank protection appear to have made matters worse.

The river Trannon is a fast Welsh mountain stream, which flows down towards the Severn in Powys. In 1978–9 a short reach near the village of Trefeglwys was given a thorough canalizing treatment. Trees were cleared from the banks, and raised flood-banks were built out of the dredged material alongside the stream course. Almost immediately it became clear that the river was kicking back at the abuse it was receiving. In the winter of 1979–80 the Trannon careered off on a course of its own. Fencing, which had been set well back from the bank, now dangled over the gulf created by the all-swallowing river. As more and more stone-filled gabions were built in to reduce the erosion which the scheme had set in train, it became apparent that Pandora’s box had been opened, and that what might have worked as a piece of traditional river canalization in the cohesive sediments found downstream had proved a recipe for disaster when applied in the unstable gravels of this upland brook. At one point, the original river bank, shored up by wire and stone, remained the only still point, actually down the centre of the fast-moving Trannon, so that it was a job to guess whether the buckling gabions had belonged originally to the left or to the right. Seven years later, remedial works were still being carried out; the raised flood-banks set far too close to the watercourse were being eroded away; the stability of the downstream bridge was threatened; and the real cost to the public purse of what was a relatively small scheme originally has yet to be clearly counted. In 1982 the Institute of Hydrology carried out trials on the Trannon, and in 1986 was able to come up with a number of constructive lessons to be learned from this sorry story. Relatively cheap methods of testing local ground conditions which have been researched by geomorphologists can act as useful warnings to engineers as to whether they are risking the kind of problems which now make the Trannon scheme, with hindsight, a questionable one to have undertaken in the first place.

Working with nature is clearly practical, as well as ecologically sound. In 1985 dredgers were busily raking up gravel from the shoals in the river to put into more gabions for bank reinforcement beside the Trannon. As part of the normal processes of a river, the stones in these shoals are neatly sorted and graded by the flowing water into an overlapping fish-scale pattern known as ‘armouring’, which makes them relatively stable. By dredging up gravel, therefore, river managers were actually de-stabilizing the river bed, thereby contributing to the erosion which they were supposedly trying to prevent. Riverside trees, whose roots increase the tensional strength of the bank material, are the best protection against erosion, especially if they are well established and are properly maintained. They also reduce land loss, since it is estimated that channels with 50 per cent tree and shrub cover on both banks require only approximately half the width for a given volume of bankfull flood-water speeding through the channel, compared to treeless brooks which erode out into the adjacent fields.

If trees are felled in the hope of gaining extra land, a river is likely to move out to take that land, and on certain types of river a great deal more besides. One has only to stand on the bridge over the Trannon at Trefeglwys and look upstream to see the stable narrow river coursing elegantly between its magnificent borders of ash and sycamore, and compare this with the immediate downstream reach, which wanders amidst a waste of gravel.

An engineered river moves out of control. After the trees had been removed, the stone and wire were set to reinforce the bank. The stream then split, turning the old bank into an island. River Trannon, Powys. © Malcolm Newson

NITRATES

Additional benefits of tree-lined streams, in reducing the effects of nitrates and phosphates in the water and in shading out the choking growth of summer weed in a river bed, which may otherwise necessitate further expensive dredging, have been recognized by Dutch and German scientists for over a decade.

The only green thing about many of our English rivers nowadays is profuse algal growth in the water, which results from an excess of fertilizer leaching off arable fields straight into the stream. Traditional drainage has accelerated this problem in two ways: by promoting farming methods which require high levels of fertilizer, and by stripping out the buffer of vegetation between the riverside and the fields. It is not uncommon for tractors to slide into a stream as they attempt to cultivate every last scrap of land beside a watercourse. This approach has led to overexploitation of stream systems. Until 1986, the steeply graded banks of one river in arable country were regularly sprayed with the approved chemical 2-4-D amine, in order to reduce the nettles, which were less good at holding the banks than slow-growing grasses, but for which perfect conditions had been established by abundant nitrogen leaching off the fields. As is so often the case in operations which go wrong, over-heavy management went hand in hand with a haphazard lack of supervision. The spraying boat, affectionately known as the ‘Black Pig’, would set off on its regular journey up the river without any adjustment on the spraying nozzle. Consequently, once the motor was started, the spray was meted out indiscriminately to riverside walls, fishermen, lovers on the bank, and nettles alike.

It is estimated that for every pound farmers spend on fertilizer on their fields, they can expect the rain to wash away a good fifty pence-worth. But the real cost of such waste is not only monetary. Water is extracted for drinking purposes from many of our lowland rivers, and high nitrate levels in drinking water can lead to illness in bottle-fed babies. Thus, while land-drainage departments promote agricultural intensification, other departments in the same water authority have to spend more public money in expensive plant to treat the water, in order to comply with EEC regulations on nitrate levels. Further expense to the water authority in cleaning up river pollution caused by silage effluent is yet another consequence of high-gear monocultural farming, encouraged by land drainage.

Peat shrinkage. The Holme Post, Cambridgeshire, showing levels of shrinkage between 1848 and 1932. © Cambridgeshire Libraries

PEAT SHRINKAGE FROM DRAINAGE

So much for the rivers themselves. Enthusiastic attempts to drain wetlands throughout the 1970s and early 1980s have in many cases failed to produce the high-quality farmland which was the object of these expensive exercises. It has now become increasingly clear that one of the real harvests of wetland drainage can be the physical ruin of the land. The most familiar example of such degradation is peat wastage. Peat wastes as a result of shrinkage, oxidation, and bacterial action, all triggered by the drying effect of drainage upon peat. A ten-year trial by the Ministry of Agriculture, started in 1980 on the Norfolk peat marshes near Acle, is indicating a fall in ground level of an inch each year. The level of the peat fenland in Cambridgeshire has fallen by up to 15 feet in many places since Vermuyden’s initial scheme was completed in the 1650s. The Holme Post, recording a drop of nearly 13 feet since 1850, presents an unrealistically optimistic picture of the problem, since it now stands in a damp nature reserve.

More convincing estimates of wastage can be made by assessing the height at which roads and even some wartime pillboxes stand proudly above the adjacent level of the fens. As the peat wastes, drainage of the land deteriorates, and so the drains are deepened, thus triggering further wastage. The lowest deposits of peat are also the most acid and so least valuable to the farmer. The Fens now resemble a gigantic and very profitable grow-bag. Like a grow-bag, however, they cannot go on producing their rich harvests of vegetable crops such as celery and carrots for ever, since once the peat has all wasted away, poor acid subsoils, especially clays, are often all that remain beneath. It is estimated that by the first decade of next century, only 20 per cent of the peat soils now present on the 138,600 acres marked by the soil map of the Ely district will remain.

Once the peat has gone in such places, some land may be insufficiently fertile even for growing potatoes, and the very best land in the country will have been reduced to mineral soils of only average quality. Such downgraded land will still have to be pumped and embanked, since it will have dropped even futher below sea level,