Our landscape archaeologist, Guardian John Rainer, has shown that, after the Great Dam was breached so many years ago and most of Roger Bigod's large Pond surged out, his successors dug a ditch below the face of the bank to drain the residual water.
In April (2020), this ditch has been restored by Philip Baskett in its original course (image 1) leading into the Fromus river (image 2)
He has also put a culvert under the gap cut into the great bank, and extended the ditch a little way above that point (image 3). He has levelled the ground of the gap, so that walkers will find it easier to negotiate and, as importantly, agricultural machinery will not get bogged down.
The work is worth inspecting — clearly visible at the bottom of the ditch is the subsoil of dense, yellowish clay, completely impervious to water. The 12th-century hydraulic engineers certainly understood the qualities of the natural materials of the site!
|1. Along the base of the Great Bank|
|2. Connected to the stream|
|3. Above the gap|
John Rainer writes,
The clay layer revealed by the ditch clearing is likely to be part of the base of the pond. Given the absence of a clay layer in the sides of the dam failure point, or in the river banks further downstream, it may not be geological. The clay might have been brought in as part of lining the pond base by puddling.
It is far too early to be confident of this; it may just be an isolated area of natural clay, or a small area of clay brought in to patch some locally leaky soil. It should be possible to use a simple hand auger to check its extent in Mere Meadow.
| pictures by Janey Cullen