Ancient water tanks of Sri Lanka to adapt to a changing climate

Over 2400 years ago, Sri Lanka, a tiny country near the southern tip of India, flourished into one of the finest hydraulic civilizations of the world. This country, at the core of the south east monsoon, has 80% of its territory covered by a dry zone prone to water scarcity. Its ancient kings built a sophisticated network of small tanks connected by canals to large reservoirs to collect and redistribute every single drop of rain the land received. The tanks were built in cascading systems, using the natural inclination and topography of the land, full of small watersheds. They kept the natural cycle of water through soil, vegetation and atmosphere. The main goal of the system was to save and re-use water, allowing cultivation of rice in the dry zone. Tanks, paddy fields, watersheds, canals and natural ecosystems were perfectly interlaced.