Geology and history

The structure of the pond, which is in a hamlet near Gislingham in Suffolk, told us quite a lot about the history. The likeliest origin is as a series of clay pits, which may well have been dug into an old stream bed. Once dug out, the farmer probably adapted the excavations to use as a moat and reservoir.

The pond bottom, we discovered as soon as we started the work, is a thick, hard layer of bluish-white clay mixed with chalk particles. Accounts of the geology of Suffolk confirm that this matches the description of a type of boulder clay, deposited by ice sheets, which is very common in East Anglia. A local construction engineer said the boulder clay stratum is at least 25 metres deep in our part of Suffolk, and is under most of the land between here and Ipswich, where it comes up against the London clay.

The pond is next to a farm cottage (ours) and a farmhouse, both of which are 16th century at the latest and may well be 15thcentury. There are also two listed barns in the old farmyard, both of which have been converted to houses in recent years, so the farm and its yard have now become four separate homes. Some archaeological research has been done on our cottage, and we are waiting for a detailed report that we hope will date the building.

The cottage unmodernised – no water, electricity or drains

During work on the cottage we went to great lengths to conserve and repair all the wattle and daub we found in the walls. The clay that made up most of the ancient daub was strikingly like that at the bottom of the pond. It seems clear from the composition that it must have been dug out of the pond at the time the houses were built, especially since the difficulty of transporting bulk material led people to use whatever was found on site. So that would date the pond to the 15th  or 16th century at the latest.

When the pond was eventually emptied and desilted, we found four distinct pits of varying sizes within the clay bottom: a small one in a shallow area, two rather larger ones in a slightly deeper place, and then a large excavation with steep clay sides which made up the narrowest and deepest part of the pond. For some reason, two of them were circled by low rings of clay, perhaps to keep rainwater back  while digging them out.

The exposed clay back wall of the cottage – attacked by woodpeckers looking for insects

Ours is the main pond, but it has arms at each end going at right angles into a neighbour’s garden, forming three sides of a square. One arm is just a shallow depression in the ground, no more than a ditch, which takes the overflow when the pond floods, but the other is deep and is still a proper pond. The previous owner of our property is convinced that this configuration shows that the pond was originally a moat, though the surface evidence of a fourth side, if there was one, has disappeared.

Two of the clay pits found during hand digging, filled now by rainwater.

There are said to be at least 2,000 moats in Suffolk and Norfolk. In his book Waterlog,  Roger Deakin says that there are more than 30 moats within a four mile radius of the church in the nearby village of Cotton. We are half way between Cotton and his village of Mellis. In Waterlog he writes:

Moats are now considered by historians like Oliver Rackham to have functioned as much as status symbols as anything else for the yeoman farmers who dug them. Mine was probably excavated when the house was built in the sixteenth century, and runs along the front and back of the house but not the sides. It had no defensive function except as a stock barrier. It would have yielded useful clay for building and formed a substantial reservoir.

The farmhouse near our pond is large and well built, and the family that lived there were probably yeoman farmers, well above the bottom of the social scale, according to a student of architectural history who included a note on the buildings in his dissertation.  So it seems plausible that the clay pits were dug to build the houses and then developed to become a status-symbol moat and reservoir.

A difficulty with the case for a moat is that neither of the present two timber and clay houses are within its boundaries. On the other hand, there are what look like old foundations of a building or a road on the side away from the present houses, and at one point these cross the pond.  The two ancient buildings now standing are on slightly higher and dryer ground, next to a still-prolific 5 metre deep well, so it is possible that the early inhabitants of the site moved their homes across the pond to a better site.

As Roger Deakin makes clear, some ancient moats were used to confine animals.  One practical configuration for an animal stockade would have been a three sided moat, perhaps with a fence at one end. So another possibility is a moat forming an enclosure without a building.

A plausible view, held by another neighbour, is that the U-shaped pond began as a bend in a stream that has since disappeared.  A ditch – now filled in by building work – seems to have run in from a field and, together with the pond, may have formed a meander in a stream. The presence of the clay pits is proof that the main part of the pond was artificially constructed, but there is no reason why the starting point should not have been an old stream bed. Stream or not, the deep and impermeable layer of boulder clay would have trapped water and would have been an obvious place for early inhabitants to look for springs and to dig for building clay, leaving rain, ground or stream water to fill the excavations, just like a worked-out modern gravel pit. It would not have taken much further effort to turn it into a status-symbol moat, whose configuration may have been dictated by an earlier stream bed.

It seems at least possible, if this has been a boggy site for millennia, that our pond dates to before the construction of the houses, perhaps to a much earlier settlement. Suffolk’s county archaeology department told us that a Saxon burial site was thought to be in the vicinity, which is one of the reasons why we were obliged as a condition of planning permission to hire a team of archaeologists (at our expense) to explore the ground around and under our cottage.

We found that the central area of the pond was relatively shallow and the bottom in that part was hard and lined with pounded gravel, sand and flint. It looked, when the silt had been cleared, like a road; an acquaintance who has worked on a number of farm ponds said that its purpose was to allow water wagons to be driven into the pond to be filled. It was also a hard bottom for cattle to stand on.

The owner of the farm, the cottage and the pond until the 1980s (who died some years ago) told a neighbour that it was last cleared in the 1930s, using shovels to load a horse and cart.  It took a whole summer. This explains why our desilting produced only a disappointing haul of objects:  mostly broken 20th century pottery, pieces of old motors, a bicycle seat, two well preserved leather boots of different sizes and the occasional small timber that could have come from a cart. It was the usual practice, our neighbour was told by the late farmer, to clear a farm pond twice a century, so the work on ours has been overdue since the ‘80s. References we found on the web suggested a typical large pond would silt up by more one centimetre a year. The depths of mud we found are not far out of line with that estimate.


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