Sri Lankan Solutions to Water Shortage
The United Nations General Assembly designated 22 March 1993 as the first World Water Day and It has been held annually since then. This article was written to commemorate the World Water Day which falls on 22nd March.
In Sri Lanka, rainfall is the primary source of water. The annual rainfall is around 1800 mm with areas such as Hambanthota and Mannar receiving only about 900 mm and some areas in the hill country receiving about 5,000 mm. In terms of quantity of water received, it is around 100 billion cubic meters per year. Out of the total water received by the island, around 40% escapes to the sea as run-off, although we often speak of the famous dictum of King Parakramabahu I, according to him which "let not even one drop of water that falls on the earth in the form of rain be allowed to reach the sea"
Sri Lanka is world famous for its water resource management. The dry zone is studded with thousands of ancient tanks of varying capacities to collect water. King Mahasena (274-301) constructed the first giant reservoir, the Minneriya tank which covers nearly 1,900 ha. Since then other large tanks such as Parakrama Samudraya, Mahakandarawa, Kalawewa etc. were constructed to collect rainwater for crop and animal production and various domestic uses. There are around 12,000 small tanks distributed across the undulating landscape in the dry zone. These tanks are not randomly located but occur in the form of distinct cascades each made up of 4-10 small tanks situated with in a single small catchments (meso-catchment) varying in extent from 100-1000 ha,.