Several centuries ago, as populations expanded into the dry zone of Sri Lanka, efficient water storage became a high priority. Most rivers and streams found in the country’s dry zone are seasonal, emerging only during the monsoon season with their flow dependent on the amount of rainfall received. The resourcefulness of ancient communities led to the creation of Village Tank Cascade Systems (VTCS) or Ellangawa (made up of the Sinhalese words ‘ellan’, meaning hanging and ‘gawa’, meaning one after the other).
VTCS consist of an intricate network of small to very large tanks (or reservoirs) connected through a series of canals. The tanks, which store water from seasonal streams, each have a specific purpose. For example, the village tank, which all other tanks in the system drain into, is used for irrigation, as well as other community activities, while the ‘water hole’ is constructed for the trapping and deposition of silt. When fully functional and well managed, the tanks provide villages in the area with a year-round water supply, thus helping the surrounding landscape and communities to thrive.
While these ancient irrigation systems still function as a crucial element in supplying water for agriculture, they have other significant functions.
