The simplest and cheapest method of lifting groundwater from an open dug well or surface water source is by means of a rope and a bucket. The job of drawing water from the well can be made easier by adding a “windlass” (a horizontal cylinder with a winch which can be turned to raise the bucket on a rope) or a “Shadouf” (an upright frame with a long pole suspended on top with the bucket hanging from one end and a weight which serves as the counterpoise of a lever at the other).
The basic Shadouf consists of a rope, pole, bucket and counterweight and is capable of lifting water up to 4 metres. The counterweight can be just a heavy rock, however, in the more advanced picottah design, one person guides the bucket while the other acts as a moving counterweight. The Shadouf is generally used for lifting water from unlined wells, streams or ponds for irrigating small fields. Approximately 60 litres/min can be lifted from a depth of 2 to 3 metres.
Advantages
• A relatively inexpensive traditional technology, which can be locally made and maintained.
• Easy to operate
• Relatively efficient (30-60%)
Disadvantages
• Limited to lifts of less than 4 metres
• Limited water yield, 60 l/min suitable for small fields