Dew Ponds in Hampshire
The ‘Dieu’ pond is an ancient relic of times long past when we could not guarantee a supply of water. Many exist and can be rich in wildlife.
Life as we know it began in a watery environment back in the mists of time. Organisms still retain their link with watery origins and without adequate supplies dehydrate and lose the race for survival.
Today, farmers, villagers and urban dwellers can usually depend on a borehole or piped water supply even if they live some distance from a river. In the past such water resources were less reliable especially on the chalky hillsides. Every population needed to maintain their own supplies of this vital resource. ‘Dieu’ or God ponds, now corrupted to ‘dew’, were constructed across southern England to augment other water supplies. The oldest ponds possibly stretch back to archaeological times but most extant ones possibly to C17.
Our dew ponds are filled from God-given water – rain. Some may possibly be ‘topped-up’ with dew but that would be insignificant. The great majority of the water is captured rainfall or seepage from the soil.
The ponds in clay areas can be in natural hollows that collect water than runs down roads or trackways. But the pond, which my students and I first cleaned out in the 1970s, near The Fox at Tangley (SU332 523) is puddled clay with a flint surround. It collects water from the adjacent road. That water is first channelled into a brick cavity to collect soil (silt trap) and so prevent it from filling up the pond. Ponds are transitory unless they are regularly cleaned deposited leaves and other debris – a dirty and difficult task, as we found out!
This dew pond was probably used for two agricultural purposes: to water sheep, hence the flint surround to discourage sheep from entering the pond and breaking the clay lining with their hooves, and re-filling the boilers of steam engines. The latter was indicated by a pipe, and sieve-like device attached, that led from the centre to the pond’s edge.
William Freeman graphically recounted the care which went into making these ponds in 1915: “Never in any part of the world have I seen a finer picture of human labour than a gang of pond-makers at work on an early summer’s morning. (After the pond has been dug out.) The clay is beaten in course by course, with exact rhythm and precision of stroke and quite extraordinary strength, each man wielding his heavy bitle, his body stripped to his waist, and every muscle moving beneath his shiny skin, like a bronze Hercules come to life. There must be no pause and no variation in stroke till the foreman cries ‘halt’, and that section of the pond is complete.”
There were at least three dew ponds within a square kilometre of Tangley and at least six more nearby.
These still watery environments, hopefully free of the dreaded fish that unthinking people often place in them, are important for nature conservation. They should be treasured features in any village’s environment.
Such isolated ponds have some unusual occupants. For example, a pond near Hatherden we cleaned out and re-watered became filled with extremely rare fairy shrimps. These attractive invertebrates have eggs that survive in a dried state of suspended animation for tens or hundreds of years, only to hatch and grow rapidly when water refills the pond.
Lack of competition by fish is an important aspect of small ponds (including in a garden). Then amphibians can breed without their spawn being consumed. Frogs, toads and newts can then occur in good numbers and attract their natural predators – including stoats, weasels, grass snakes and kestrels.
Dragonflies will be attracted to any such open water and females will lay eggs. The hatched nymphs are small predators in the pond’s food chain, feeding off water shrimps, water lice, daphnia (water fleas) and myriads of fly larvae.
Ponds are also wonderful for children. School-aged children will pond dip and teachers and parents enthuse their charges with the diversity of life encountered.
Assuming light can reach the water’s surface, water plants will grow, and in the winter, die back. Such decomposition, in the anaerobic conditions of winter, will eventually fill the pond. Dew ponds are transitory features of the environment unless action is taken to clean them out. So, if you know of any ponds do keep the local community informed about their condition – and take action!