Theni (Tamil Nadu), April 22: Strong and gusty winds have stymied a state government experiment to try and cut water losses through evaporation in the Vagai dam river by placing thermocol sheets on the water surface.

Tamil Nadu minister for cooperatives Sellur Raju who inaugurated the unusual method to conserve water in the drought-hit state himself saw the attempt go awry as gusty winds blew the sheets in different directions in the river.

The minister later held discussions with officials and staff of the state's public works department who had placed the thermocol sheets on the surface of the water on possible ways to overcome the problem posed by the winds, officials said.

Water from the Vaigai dam flows through six water starved districts of south Tamil Nadu including Madurai, Sivaganga, Ramanathapuram, Theni and Dindigul districts.

Two civil engineers in Maharashtra had two years ago proposed through a study that thermocol can save 32 per cent water on small farm ponds at a cost of about Rs 48 per square metre for material costs.

Narhari Chaudhari, associate professor of civil engineering at the Karmveer Kakasaheb Wagh Institute of Engineering, Nashik, had analysed the efficiency of thermocol sheets to prevent evaporation on farm ponds in the region.

"A few farmers near Nashik are already using this technique to conserve water for their sugarcane and pomegranate crop," Chaudhari told The Telegraph over the phone today.

A thunderstorm on March 15, 2015, had broken some of the thermocol sheets on the farm ponds, slightly reducing the efficacy of the technique, Chaudhari had reported at a conference on hydrology in Roorkee later that year.

The Tamil Nadu effort was aimed at a river, in contrast to small farm ponds in Nashik. The thermocol material deployed wasn't enough to cover the water's surface. The minister, Raju, said such methods are used abroad to reduce evaporation.

He said the state government has allocated Rs 10 lakh to try out different technologies to prevent water evaporation.

Madurai collector K. Veera Raghava Rao said different methods would be adopted or experimented to save water which is in 10 to 12 hectares of waterspread area in the Vaigai dam.

He said 1.2 million cubic feet of water is lost because of evaporation every day.

On the use of thermocol, he said this was done as the material was non-polluting.

But Rathnam, a scientist, differed, saying thermocol is non-biodegradable and can harm fish when they break into pieces.