``The innovation is unique in that it has been conceptualised and implemented at the village level. The pump has been irrigating the fields of more than 50 families in Mangal's village for more than a decade now,'' says Dr Sanjeev Jain, assistant professor, department of mechanical engineering, IIT Delhi.

Hailing from Bhailoni Lodh village in Lalitpur district in Uttar Pradesh, Singh did not have the benefits of a technical education. This did not stop him from getting the idea of devising a water turbine while looking at the familiar motion of a firkee (spinning toy) made from mango leaves by village children.

Using wooden planks and iron bars on a village lathe machine, Singh developed a rotor wheel with a diameter of 2.8 metres, mounting it over a mild steel shaft. The shape of the water wheel was similar to that of the centrifugal pump. Singh then used a small check dam to get the elevation of water needed in a turbine.

Says Dr Santosh Satya of the Centre for Rural Development and Technology, IIT Delhi, ``The critical factors while designing a turbine are the shape of the blades of the wheel, its diameter, the height of the dam and the flow of the stream. At a time when big dams lead to environmental disasters, a smaller alternative in a renewable source of energy is the need of the hour.''

According to a study, commissioned by CAPART and conducted by Dr T P Ojha, director, Central Institute of Agricultural Engineering, the technology has proved successful. ``It needs to be popularised in the region in the light of the abundance of streams and nullahs (rivulets) here,'' says the report.The 15.5-foot diameter wheel of the Mangal Pump is operated at 8 to 14 rpm. This results in a pump impeller speed of about 1,460 rpm. Noting the robust designing of the wheel, gear drive and pump, the report however points out the poor quality of the delivery pipe used for discharge. In the rainy season, when the water discharge is higher, the delivery pipe developed serious leakages at many locations, according to the report.

Despite its considerable economic benefits (an imported turbine costs Rs 4 lakh and the Mangal Pump only Rs 1.25 lakh), Singh's device has found no takers in his state. ``I tried talking to both the district administration and state authorities, but to no avail. CAPART was the only agency that gave me a grant. Even after I got a patent in 1990, the government failed to spread its use to other villagers,'' he says.

Hydel power turbines in India can be divided into three categories, depending on the height of their design. ``While finance is easily available for the high-head and medium-head installations, low-head turbines, that draw water from shallow streams or nullahs, don't get the same attention,'' says Jain.

In Uttar Pradesh, better off farmers have installed diesel or electric pumps to lift water from rivers and streams to irrigate their crops. But for most, the recurring cost of fuel is too high. Besides, the cost of irrigation in a hectare by conventional canal irrigation is estimated at Rs 50,000. Even the so-called low-cost drip irrigation costs Rs 20,000. In contrast, the Mangal Pump can irrigate a hectare in less than Rs 5,000.