Srilanka, Oct. 19 -- The ancient kings built major medium and small-scale tanks mainly in the Dry Zone including the North Central Province for agriculture, domestic use and drinking purposes. Today our tank system is a world heritage showcasing the unique and marvellous hydraulic engineering expertise. The irrigation systems which date to the 5th century BCE enables the Irrigation Department to store 4,000 million cubic metres of water in 75 major tanks and 170 medium tanks and another 3,150 million cubic metres of water storage in the reservoirs built under the accelerated Mahaweli scheme, such as Kotmale, Randenigala, Rantambe, and Victoria. However, the technology of our skillful ancestors are quite advanced that it can't be deciphere...