Agri Kultuur August / Augustus 2018 | Page 25

upper stream width of 20 m, midstream 10 m, and downstream 5m. Sri Lanka’s three historical irrigation and drainage systems are Elahera Anicut, Kantale Wea and Sorabora Wewa systems. The Elahera Anicut (barrage) was built in 65 to109 AD and consists of a diversion structure at Elahera across Amban Ganga (a tributary of Mahaweli Ganga). It irrigates 6 700 ha. The Elahera Anicut (barrage) was built in 608 to 618 AD and covers an area of 23 km 2 and has a carrying capacity of 140,6 million cubic meters at full capacity. The dam is 16,75m high and 2,5km long. It irrigates 7 513 ha. The Sorabora Tank was built in the 2 nd century BC. It is damming the Diyawanna Oya river with a 485-meter embankment. The tank covers 4,5 km 2 and holds 14,6 Mm 2 of water at full capacity. The sluice gates are expertly cut into the natural rock and is about 1,8m wide. AgriKultuur |AgriCulture 25