Life of a Chalkstream. Simon Cooper
I pushed on up the river the sun burnt off the cloud; it was getting warm but I still had two more things to find: the Drowners House and the brook. Wading in gin-clear water under an azure blue sky is hardly the toughest job in the world, especially in a chalkstream like the Evitt that has no great incline to it. It doesn’t race like a tidal river or rush in torrents like a mountain stream; rather it glided across the face of my waders at a gentle walking pace. Looking upstream from where I was standing I could see a full 300 yards of river ahead, and I’d be hard pushed to swear that I could see a difference in height. In fact I knew that the source, 30 miles from the sea, is only 85 feet above sea level, so that is no more than two inches’ drop in every hundred yards. For potomologists – those who study rivers – this is just about as benign a flow as a river can have.
This is a floodplain that is almost as flat as the river that flows through it, and it was only in the far distance, at least 3 or 4 miles way, that I could see the sheep-grazed downs that gradually rose to a few hundred feet. Long, long ago, in the ice age, the river valley was carved as a shallow ravine, but gradually, over millennia, the water flowing to the sea had left soil, silt, gravel and sand behind after the floods of winter, creating the flat plain on which the water meadows sit today. But nature did not do this all alone; man played his part. It is the conjunction of water with meadows that makes this such a very special landscape. There are meadows the world over, but in very few places has man harnessed the seasonal floods to irrigate and protect the grassland for the sole purpose of making the sward grow faster, lusher and more nutritious for cattle to graze. This ancient agricultural practice has, by chance and unintended consequence, created a home for a unique collection of creatures that are my constant companions.
Through a gap in the reeds I thought I spied what looked like the Drowners House some way across the meadows, with a bedraggled thatched roof covered as much by wild grass and weeds as by darkened straw. Heading for the gap to haul myself out of the river I crossed the path of a water vole swimming fast along the edge of the reeds, hugging the margin for protection. For such small creatures, seemingly so ill-adapted to water, they really can swim fast. In the water there was no way I could keep up in my waders, and on the bank I’d need to maintain a brisk walk as they stretch out their brown furry bodies, nose poked up in the air while their legs paddle like fury.
But this one, in common with all water voles, can only keep up the furious burst of speed for a short while. Quite suddenly he stopped, gave me a look with those little black eyes and with a plop disappeared beneath the surface. Under the surface things are a mad scramble for the water vole. With all that waterproof fur they are naturally buoyant, and their tiny lungs are not suited to holding their breath for long. But he had chosen to dive at this spot for a purpose. Beneath the water he wove between the roots of the reeds, heading for the bank. I could track his progress by the muddy trail he was leaving in the water until he reached the entrance to the burrow. At the tiny hole – no bigger than the size of an egg, just above water level and shiny from constant use, he stretched out the hand-like claws of his front legs, pushed them into the soft soil and using the purchase, squeezed himself inside the burrow.
Like the kingfisher, these are the breeding months for our water vole (Arvicola amphibius), which is now probably into its third or possibly fourth litter of the year, having started back in March. In the burrow, lined with dried grass torn and gathered from the bank above, anywhere between five and eight tiny voles, no bigger than your thumb, will be mewling for food. Back and forward go the adults, for anything up to eighteen hours a day. Fortunately they are pretty promiscuous in their diet on the herbivore scale. Little tooth marks on the reeds and sedges are easy to spot. Wild mint and watercress are chewed with relish, but of all the things it is wild strawberries that they fall on like mammals possessed. But really they will eat anything; the family demands it.
Doing the maths, you’d think that we’d be overrun by water voles by June – after all they are not great travellers and this one nest will have produced fifteen offspring by now. The truth is that being born a water vole is a high-risk incarnation. First, the weather might get you: lengthy bouts of bad weather, or worse still an ill-advised burrow that gets flooded. Inside the burrow you might be generally safe, but the common brown rat or worse still a stoat or mink will make short work of you and your family if you’re discovered. Once outside you are assailed from above and below: owls, buzzards, otters and pike are just four of the predators who see you as a tasty morsel. If you make it to the semi-hibernation of winter you have done well.
By now it was getting a bit hot for trudging across rough meadows in waders, so I took a direct line to the Drowners House, stumbling on the way into what were most likely carrier ditches, still soggy at the bottom beneath the tangled grasses. Ducking down under the oak lintel of the doorless entrance I entered the cool of the house. With no windows it took a few moments for my eyes to adjust to the dark, while some streaks of light came through the holes in the dilapidated thatch, illuminating the river that ran beneath the ragged floorboards. A house with a river running through it for no apparent purpose? It could only be for the drowners.
The drowners are long gone, the purpose for their livelihood disappearing when modern agricultural methods consigned the water meadows to history. But for four centuries these were the men who regulated the flow of water from the river, through the drains and carriers dug across the meadows, to quite literally ‘drown’ the late winter and spring grasses in water. Warming the soil and air of the meadows – grass grows at 5°C, chalkstream water is 10°C – plus all the nutrients the water carried with it, was the perfect way to get cattle grazing earlier and thus create heavier crops of hay. Of course all this came at a price in terms of working conditions. Obviously the times when the water levels needed most adjustment, hourly and daily, came when the weather was most foul, so the drowners built these houses. They built them over the water for the same reason they drowned the grass – warmth.
I didn’t need to take out a thermometer to check the temperature inside the house today; I knew it would be exactly the same as the water – 10°C. The thick triple-skinned red-brick walls, damp from the foundations in the wet land, helped keep the place the same temperature all year round. Today I was grateful to find it a full 10° cooler than in the sun outside, but I doubt nearly as grateful as the drowners were when the mercury fell below freezing in winter. Today, other than the house itself, there is not much evidence of the drowners’ tenure. There are soot-blackened nooks hollowed out in the brickwork as candle-holders and some initials carved in the oak beams, but the current residents are mostly house martins that have coated the walls with white guano from their nests in the rafters above.
I found myself a handy log, placed it up against the hut wall and sat down to contemplate my options. To say the river and meadows were in crisis would pitch it too strong. Severe neglect was closer to the truth; a river caught in a spiral of decline. For all the beauty of the river and the wildness of the meadows the creatures were in retreat. With every year that passed the spawning grounds were growing fewer as the streams and carriers progressively became blocked. Along the banks the scrubland was encroaching, eliminating the wide open spaces that natives like the water voles require. In the meadows, without proper grazing, the meadow plants were being crowded out. Untended, the clear, fast chalkstream waters of the floodplain would revert to a swampy morass, with insects like the olives and mayflies disappearing.
It could be saved, but was it worth saving? The answer had to be yes. The question now was how.
* I have no hard or fast rule about what to do if you don’t reach hard bottom. Generally if I am still sinking when the gloop reaches my waist I rapidly turn tail to heave myself back onto the firm bank with a fair imitation of an arthritic walrus.
THIS MORNING I found a bat caught on a hook that was dangling from a snagged fishing line on a branch overhanging the river. This is not the first time I have found bats snared like this. Bats with their super sonar hearing home in on a discarded fishing fly mistaking it for a real