Stepwell with tunnel system helps transform Rivona farm

Panaji: Dug decades ago on a hillside in Rivona, septuagenarian farmer Pandurang Patil’s stepwell is hand-carved with tunnel systems known as surangam, built using an ancient engineering technique once practised in parts of South India.“In plains, underground aquifers spread water evenly in broad underground water tables. One person digs a well at 8m, and nearby wells will also find water around the same depth. In hills, however, water comes only as narrow streams of seepage moving through rock fissures,” he told TOI.This makes conventional square wells inefficient in hilly terrain, as only one side may actually bring water while the other sides merely store it.To address this, earlier generations dug horizontal tunnel passages parallel to seepage-bearing rock layers to capture groundwater before it escaped downhill.The tunnels beneath Patil’s stepwell extend around 40m into the hillside. Tall enough for a person to walk through, the work was dangerous and highly specialised.It was carried out by craftsmen from a traditional community in Kerala’s Kasaragod district, who were known for identifying hidden underground water channels in sloping terrain. Local folklore linked them to the legendary escape tunnel built for the Pandavas in the Mahabharata.“They claimed to be descendants of those tunnel-makers,” Patil said with a smile. “I don’t know how true it is.”What he does know is that the craft is disappearing.“The next generation did not continue this work. It was risky. Digging 40 or 50m into a hill with no support system was dangerous. I think I was lucky enough to find one of the last people who knew how to do it,” he said.Before the stepwell was built, Patil’s farm relied on several small springs that produced only trickles of water during summer.“We had around 5,000 trees, and the entire family was engaged only in manually watering them. The stepwell changed that. Water from multiple small springs was channelled into a central storage well connected to pumps and sprinklers,” he said.The impact, according to Patil, was significant.“Our cultivated area doubled, and crop yield increased by around 50%. Mechanical irrigation gave us time to focus on pollination, manure, harvesting, fungicide sprays and other farm work,” he said.He also recalled earlier decades when electricity connections for agricultural pumps near rivers were reportedly disconnected during summer to prioritise urban water supply.“Several plantations died during those times,” he said.Now, Patil fears history could repeat itself as Goa faces recurring summer water shortages, falling reservoir levels and increasing dependence on tanker supplies in urban areas.“You cannot keep approving massive projects that consume huge quantities of water and still expect abundance. We are allowing villas with jacuzzis and swimming pools. But you cannot import water the way you import electricity. When future water shortages come, people should not expect local farming communities to sacrifice again,” he said.“Tunnel systems are difficult to replicate in urban areas, but Goa already has a more immediate solution, restoring storage capacity in existing dams through desilting,” he added.