Large ponds are transformational in a landscape, both in terms of aesthetics and benefit to wildlife. This will often involve building of a dam bank in all but the flattest sites, a rare thing to find in the South Devon landscape. The advantage of a slightly sloping site is that the excavated material is used in construction of the pond and therefore doesn't need to be removed from site or re-purposed somewhere else. A liner is usually required to achieve a stable water level. The liner is sandwiched between two layers of very heavy duty geotextile allowing for a 300mm layer of inert material such as excavated subsoil from the pond or gravel to cover the liner, thereby creating a natural pond and further protecting the pond liner from puncture and UV deterioration. This also allows for stone-work to be built on or below water level and sculptural feature or stepping stones of a tonne or more in weight to be sited in the margins.