So how do you make a dew pond? In the early 1920's dew pond makers would travel through the southern counties for around six or seven months from September. This would link in with the production of straw at the end of the harvest. With a period of four weeks to make a 22 square yard (7.102 square metres) pond, the pond makers would take the time to dig a hole and then start with the crown and only extending the pond when the conditions called for it. The work started that day had to be finished before the dew had fallen - does dew fall or rise (this article may give you the answer) - and a layer of straw had to be added for insulation at night. Work stopped for frosty and inclement weather. It is suggested that puddled clay was used to make the majority of the pond (it had been estimated that seventy cartloads of clay was needed for a single pond) - however the structural analyses of dew ponds in the region of Brighton suggested that puddled chalk was also used. Martin Snow, a dew pond spotter, has found between 100 and 200 ponds in West Sussex alone. The location of a dew pond is created so that it exploits both mist and the rain clouds from the coast. This Country life article lists 2 contractors.
