Puddling is a technique used to create watertight linings for water bodies like channels and ponds. It involves mixing clay with water to form a workable material called puddle clay. This material is then applied in layers to the surface to create a barrier that prevents water leakage.
The use of puddling was pioneered by James Brindley in the late 18th century. It was widely employed in the construction of canals in the UK, and later in the construction of earthfill dams. Puddling's use in dams has since been superseded by more advanced technologies, but numerous early dams utilizing puddle clay cores remain in operation today. The process involves adding fibrous materials to puddle clay to create a more durable building material known as cob, which has also been traditionally used in construction.