Which of the following is not an ancient water harvesting structure?(a) kattas (b) sargam (c) kulhs (d) surangams

Correct Answer: (b) sargam

Explanation:

 Sargam is not an ancient water harvesting structure.

Kattas were the temporary check dams that were built across the streams and rivers to conserve water for summer irrigation, commonly in the districts of Kerala and Karnataka. 

Kulhs were the traditional irrigation method where water flowing through the streams were diverged in man-made canals to provide water to the villages at the lower hill side. It was a commonly practised method in the hilly areas of Himachal Pradesh.

Surangam (also known as Suranga or tunnel well) is a traditional water management method where a horizontal tunnel is dug into the slope of laterite hill and through the gravitational pull, the underground water was extracted and collected into the storage tank. This method provided a reliable supply of water for domestic and irrigation purposes in the districts of Kerala and Karnataka.