Impact of Lined Canal on Shallow Tubewell Irrigation and Their Acceptability by the Farmers

The comparative conveyance losses between lined and unlined canals, impact of water saving on command area development and irrigation cost, and farmers ’ acceptability of lined canal in shallow tubewell (STW) irrigation schemes were studied during 2010-11 Boro season at three upazilas: Manikgonj Sadar of Manikgonj district, Dhamrai of Dhaka district and Mithapukur of Rangpur district. The conveyance loss was measured using inflow-outflow method and focus group discussion (FGD) was carried out with the pump owners and farmers to assess the impact of water saving on command area development and the acceptability of lined canal technology. Average conveyance losses were found to be 41, 48 and 45 % in the existing earthen canals; 18, 21 and 24 % in improved earthen canals; and 12, 11 and 13 % in pre-cast canals at Mithapukur (M1), Manikgonj Sadar (M2) and Dhamrai (D) schemes, respectively. The water saving did not increase the command area in any of the schemes but reduced the irrigation time and saved fuel requirement for irrigation. On an average, 32, 23 and 30% fuel were saved by improved earthen canals where as 45, 46 and 48 % were saved by pre-cast canals for M1, M2 and D schemes compared to earthen canal. The benefit-cost ratios of improved earthen canals were 1.36, 1.38 and 1.30 where as 3.36, 4.28 and 3.34 by pre-cast canals for M1, M2 and