Irrigation development is an important means for achieving food self sufficiency by many arid and semi-arid countries, in order to address the main challenge caused by food insecurity and water scarcity. This will likely be difficult, because extensive area of irrigated lands have been and are increasingly becoming degraded by salinization and waterlogging resulting from over irrigation and other forms of poor agricultural management. This study attempted to evaluate irrigation water quality and its management in the context of soil salinization in Gumsellasa irrigation scheme. The scheme got operational in 1996, but farms have been facing danger of soil salinization with in such short period. In order to identify the cause and prognosis of this salinity problem water and soil samples were analyzed in a laboratory for both dry and wet seasons. Salinity contour maps of the scheme were also prepared for both seasons. Currently practiced irrigation schedule for onion and maize were compared with CropWat simulated optimum irrigation scheduling. Researchers, students and farmers could potential benefit from this study.