In Ethiopia, many constructional exercises are finished by utilizing the old convectional cast-in-situ method. But the current technology shows various priorities of precast constructional strategy over the cast in situ technique. The general objective of this study is to recommend which of these two main systems of casting concrete is better for the construction of irrigation canals according to different points of view like existing strength, hardness, and durability by conducting non-destructive tests like visual inspection techniques and hammer rebound tests and to characterize defects. Koga irrigation main canal is selected as a case study area. Because it has 15.2km in situ and 4.5Km precast concrete linings. This research involves qualitative and quantitative approaches. The sources of quantitative data will be both primary data or direct field measurements and secondary data. The result of this study shows that the very severe defects, lower compressive strength, and uniformity due to the high level of difficulty to pour and vibrate the concrete on the side slopes of the canal was observed in the in situ part of the concretelined canal. Whereas, removal of closely spaced and less water-tight joints, as well as the growth of grass and vegetation and grass in the joints, are observed at the precast part of the canal lining. Finally, this research recommends either providing tensile reinforcement on the in situ concrete canals or providing water-tight joints for the precast concrete part. Keywords: Conventional Cast in Situ Concrete, Pre-Cast Concrete, Non-Destructive Test