Project Archaeologist Trevor describes the latest addition to our Bronze Age enclosure as a dew pond joins our Bronze Age Dunch Hill Roundhouse.

It might not look much from the photograph, but this little pool of water is our dew pond. Although our Bronze Age roundhouse is all but finished, that doesn’t mean we are finished with the Bronze Age. 

We have been carrying on working with the fantastic Operation Nightingale team and this is our latest creation. So, what’s a dew pond? Well, they are small water reservoirs but, unlike conventional dams, they don’t necessarily have a ‘catchment’. A catchment can be either a stream or river, or an area of higher ground surrounding a dam, which slopes towards the dam and directs runoff water into it when it rains. As a result of this, dams have a downstream wall that prevents the water following the natural course of the stream or sloping catchment that feeds it and, therefore, draining away. 

Because of the chalk geology, dew ponds are a very much a feature of the ancient landscape of the South Downs. That’s because chalk bedrock is so porous that any standing water quickly drains away. Sometimes the water that percolates down through the chalk will hit a layer of less pervious geology below and springs will form, typically at the base of one of the higher hills. These springs can be dammed to provide water for livestock. In the South Downs, that usually meant sheep, which have shaped the landscape and ecology of the region since the Bronze Age. But where no springs are available – for example, on hilltops - dew ponds come into their own. All they do is collect rainwater and store it, although the name ‘dew pond’ is said to derive from an old belief that they actually collected their water from dew. Of course, any water that accumulates in them, whether from dew, fog, melted ice or rain will be stored, but rainwater is the main contributor.

Dew ponds, which are much larger than our little tiddler, can be found in many locations around the South Downs, including a variety of points alongside the South Downs Way walking trail. The Queen Elizabeth Country Park, only a mile or so north of Butser Ancient Farm, has a restored dew pond not far from the visitor centre. That one is lined with concrete to prevent the water draining through the underlying chalk. That is a modern concession, but dew ponds were traditionally lined with clay and that is how we have built ours. Often the clay has other materials added – such as straw laid beneath the clay as an insulative material and ash from fires added to it. The ash, it is said, is not palatable to earthworms – whose otherwise helpful burrowing is not good for water retention! Our dew pond is clay-lined only, no straw or ash. So, we wait with bated breath to see how long it will endure.

In terms of archaeology, dew ponds are generally impossible to date accurately. We know from charters as far back as the Anglo Saxons that they were used in the medieval period but, beyond that, it is very much a matter for debate as to whether dew ponds were a feature of prehistoric farming. However, our Bronze Age settlers at Dunch Hill, the site of the original roundhouse upon which ours is based, were certainly farmers. They had sheep and other animals and were on chalk bedrock, so they had to have a reliable water source for their animals as well as themselves. Many Bronze and Iron Age settlements in the South Downs, as well as in other parts of Britain, were on hilltops, without a natural and nearby water supply, so it is conceivable that dew ponds or something similar were in use. 

In any event, our dew pond helps us place our Bronze Age roundhouse in context. Britain has had an agricultural economy since the Neolithic farming revolution 6000 years ago. Agriculture was predominant in the majority of people’s lives until the Industrial Revolution of the 18th and 19th Centuries. The Bronze Age fits squarely in the middle of this timeline, so our dew pond is a small but meaningful addition to the small enclosure we have created for the roundhouse’s setting. The enclosure itself is reached by a double fence line that represents a ‘droveway’ for moving livestock. It is fenced to prevent the unwanted incursions of our ancient breed Manx Loughton sheep (unwanted because they are fond of eating a lot of the material we have built the roundhouse from!), and it sits beside both the sheep enclosures and the neighbouring farmer’s crop fields. The Bronze Age was a time of significant intensification of agriculture. We see in the archaeology of Bronze Age sites a lot of evidence of domestic farm animals and cereal cropping, and of the land being divided up into field systems - there is even clear evidence for hedges and fences. It’s really appropriate, therefore, that we tell that story to everyone who comes to visit us. So, our dew pond has now become a tiny part of the telling of that huge story of more than 1500 years of British prehistory.