An assessment of the physical status of the village tanks in the Paranahalmillea cascade

Abstract

Physical status of the village tanks in the dry zone cascades of Sri Lanka has been drastically deteriorated. Structural condition of the traditional village tank system had been maintained by traditional village community. The main objective of this study was to identify the present physical condition of the tanks and to provide recommendations to the PLAN Sri Lanka (NGO) to rehabilitate the dilapidated tanks to maintain the sustainability of the cascade system. A baseline survey was conducted to assess the individual tanks in the Paranahalmillewa cascade in 2007/08. Data of the extent of catchments, command and water spread areas of the tanks were confirmed based on various secondary sources including (Fl/TS) and F-3 sheets, survey conducted by the Rural Minor Irrigation and Govijana Survey Department. Primary information was gathered through the discussions with official staff of the Medawachchiya AG A office. Focus group interviews were also conducted with appropriate persons/institutions. 35 tanks have been identified in this cascade in various development stages. The current status of the physical structures of the tanks in the Paranahalmillewa cascade has been assessed by Physical Status Scoring (PSS) method according to the criteria given by IWMI research report No 13 with some small modifications. Some of the tanks were identified as abandon, silt trap, forest and animal exploit tanks. About 23 tanks are basically occupied for paddy cultivation. More than 14 tanks did not at least a single sluice. 07 tanks had only natural spillways with broken stage. In the PSS assessment, 21 tanks have been identified for rehabilitation in various stages. Out of these 21 tanks, 10 tanks were identified for the moderate repairs and 11 for minor repairs. 14 tanks were identified for major repairing stages. Based on the PSS results, some of the tanks were rehabilitated by PLAN Sri Lanka.