Circles of life
Seemingly magical, yet carefully made by man, dew ponds are vital for the health of our wildlife, explains Simon Lester
MUCH mystique and intrigue surrounds the history of dew ponds, in that these appealing, saucer-shaped oases were once thought—rather romantically and fancifully —to be able to glean water from the air and replenish themselves by magic. Rudyard Kipling summed it up perfectly in his poem Sussex, of 1902, which includes the lines: We have no waters to delight Our broad and brookless vales— Only the dewpond on the height Unfed, that never fails. Dew, cloud, mist and fog ponds—also known as sheep or ‘ship’ ponds in the local dialect—have dotted Britain’s chalk downlands ever since ancient civilisations settled there, although most are far more modern. In areas that boast free-draining soil—such as Sussex’s North and South Downs and the limestone White Peak in Derbyshire—where rain disappears quickly and there are few streams or springs, man had to use his ingenuity to trap and retain precious water. Indeed, as these places were so important for grazing livestock, it would have been impossible to service the increasing national sheep flock—which produced the wool that, in turn, provided one of Britain’s most important sources of wealth— without natural sources of water. As it was thought that these manmade watering holes captured moisture from the air through condensation in dew and mist (hence the charming name), attempts were made to insulate the structure so the water remained colder than the earth and, when the dew or mist fell, it hit the cold surface of the water and dropped its own moisture into the pond. In reality, it has been proven that the main source of H2O for these ponds is actually rain, which diffuses some of the alchemy surrounding them. Furthermore, the insulation keeps the water temperature low, which decreases evaporation. In the old days, the real skill lay in making these elaborate vessels watertight, as any leakage would render them useless. It was up to the craftsmen who fashioned them out of the earth to make them strong enough to withstand the sharp hooves of stock, as well as the roots of plants from the top and the ravages of earthworms and moles from below. In 1922, a Mr Edward Coward of Devizes in Wiltshire had a 30ft-diameter dew pond built, which required 70 carts of clay and 12 tons of lime. According to a report in the Wiltshire Gazette of that year, specialist
dew-pond building gangs would work from September to March, as the labour required was too intense to be done through the heat of the summer. Clay and lime also dried too quickly in hot weather, causing cracks, although, in the winter, days would also be lost through frost and heavy rain. Back then, it would take a craftsman and three workers a good month to complete an average pond. The process began with the digging of a saucer-shaped hole, before a bottom layer of chalk or lime was compressed using a horse and cart and a layer of straw insulation was added. Another layer of clay, as the Gazette explains, was ‘thoroughly puddled, trodden and beaten in flat with beaters, a coat of lime is spread, slaked, and rightly beaten until the surface is as smooth as a table, and it shines like glass’. Finally, a further layer of straw was added and the surface covered with flint to withstand the pressure of cattle and sheep hooves. As is the case with hedge-laying, techniques varied from region to region, depending on the materials and resources that were available to local workmen. It is sobering to note that, in 2006, the cost of creating a new 10yd by 10yd dew pond with modern materials was quoted at a hefty £12,000, which is an awful lot more than the paltry £40 labour bill Coward paid in 1922. As with so many innovations, dew ponds for livestock soon had their day, eventually being superseded by cattle troughs. At first, these were filled with clean water piped from the ground by wind pumps; nowadays, by modern miles of bluealkathene-piped mains water. Sadly, many of the estimated 500 remaining dew ponds in the country have fallen into disrepair, which is a great shame—ponds in general offer fantastic habitats that support a diverse range of flora and fauna. Because these small bodies of water are dotted throughout the countryside, they all differ in some way, which gives them a rare power for greater biodiversity, each one acting as a hub. Frogs, newts and toads need water to breed, as do many insects, such as dragonflies and damselflies, whose larval stage is dependent on it. Birds need water to drink and bathe in, too, with some feeding on the insects and worms that proliferate around ponds and using the soft mud to build nests. In the late 19th century, there were more than one million ponds in Britain, but, by 2007, as noted in Farming and Birds by Ian Newton, studies showed there were only 478,000. Disturbingly, the biological condition of only 8% of these was classed as good—the remainder being poor or very poor, due to pollution from agricultural chemicals. It is odd that these important habitats have not featured more highly in past agri-environment schemes. Hopefully, the Environment Land Management Scheme will encourage and reward landowners and farmers to renovate old ponds and create new ones, too.
In free-draining areas, Man had to use his ingenuity to trap and retain precious water