Puddle is a watertight material based on clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

 used in building and maintaining canal

Canal

Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

s or reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

s. Puddling is the process of lining the channel with puddle.

Clay or heavy loam is chopped with a spade and mixed into a plastic state with water and sometimes coarse sand or grit to discourage excavation by mole

Mole (animal)

Moles are small cylindrical mammals adapted to a subterranean lifestyle. They have velvety fur; tiny or invisible ears and eyes; and short, powerful limbs with large paws oriented for digging. The term is especially and most properly used for the true moles, those of the Talpidae family in the...

s or water voles. The puddle is laid about 25 cm thick at the sides and nearly a metre thick at the bottom of a canal, built up in layers. Puddle has to be kept wet in order to remain waterproof so it is important for canals to be kept filled with water.

The clay is laid down with a tool called a punner, or pun, a large rectangular block on a handle about 5 feet (1.5 m) long, or trodden down, or compacted by some other means (e.g. by an excavator

Excavator

Excavators are heavy construction equipment consisting of a boom, stick, bucket and cab on a rotating platform . The house sits atop an undercarriage with tracks or wheels. A cable-operated excavator uses winches and steel ropes to accomplish the movements. They are a natural progression from the...

 using the convex outside of its scoop, or, historically, by driving cattle across the area).

See also

• Canals of the United Kingdom
  Canals of the United Kingdom
  The canals of the United Kingdom are a major part of the network of inland waterways in the United Kingdom. They have a colourful history, from use for irrigation and transport, through becoming the focus of the Industrial Revolution, to today's role for recreational boating...
  
  
• History of the British canal system
  History of the British canal system
  The British canal system of water transport played a vital role in the United Kingdom's Industrial Revolution at a time when roads were only just emerging from the medieval mud and long trains of pack horses were the only means of "mass" transit by road of raw materials and finished products The...