India, April 6 -- A few years ago, the 17th-century Bansilalpet stepwell in Secunderabad was buried under nearly 3,000 tonnes of reeking garbage, accumulated over decades.

Today, it is one of the city's most vibrant public spaces. Its waters-- holding steady at nearly 28 feet even in peak summer-- are now used by local residents for drinking and domestic needs, making Bansilalpet the first restored stepwell in Telangana to serve as a direct source of drinking water.

Bansilalpet is not an isolated story. Across India - from Hyderabad to Tamil Nadu, Rajasthan, Gujarat and Maharashtra - a quiet movement is underway. Communities, conservation architects, NGOs and governments are reviving centuries-old stepwells, temple ponds and underground...