Nachaduwa Wewa Reservoir created by Nachaduwa Dam in Malwathu Oya River Basin in Sri Lanka. Nachchaduwa dam is an ancient structure constructed in 1906. It is a reservoir in the region of North Central, the country of Sri Lanka with an average elevation of 96 meter above sea level. The area is mildly populated with 140 people per km².The reservoir is recognized for the contribution of farmer organizations in fully managing the sub system dis tributary canals and field channels from funds generated internally.
The Tank which had got ruined in the past was rehabilitated in 1917 and its capacity improved. In 1957 a huge flood did cause severe damage to the tank. However in 1958 the rehabilitation of the tank was done and its capacity augmented to enable it to receive water from the Mahaweli System. Three thousand and four hundred farm families are now being benefited by this ancient tank. While the Operation and Maintenance of reservoirs and main and branch canals etc. is undertaken by the Irrigation Department, fourteen farmer organizations take care and manage the sub system of dis tributaries canals and field channels from funds generated from their members.