Environmental Impacts of Small Scale Irrigation Schemes: Evidence from Ethiopian Rift Valley Lake Basins

Abstract

This research has been carried out in the Rift Valley Lakes Basin (RVLB), which is one of the twelve major river basins in Ethiopia. The RVLB has been considered in this research due to its high priority that comes from the significant ecological and environmental interest from different sectors. The research has tried to compare the relative environmental impact of Bedene Alemtena, Eballa, Argeda and Gedemso irrigation projects. Impact assessment at the community level has been collected on a base of key informant interviews and ad- hock technique. For the study, a summary of two sets of structured questioners are also used. Check lists, matrices, and rule based analysis are used to aggregate a scaled value of the individual parameters collected through the interviews and physical observations at the four sites. Deforestation, overgrazing, poor watershed management, soil salinity, soil acidity, communicable and non communicable diseases, and water logging are the major problems of all schemes. Specifically, about 34% of respondents have encountered soil fertility deterioration in Argeda, Gedemso and Bedene Alemtena irrigation projects with high significant variation (X2, 97.7). Land degradation scenario after the implementation of the projects is also reported in Argeda (19.9%), Gedemso (10.4%), Ebala (23.8%), Bedene Alemtena (33.3%) (X2, 86.3). About 76.2 % of farmers in Argeda irrigation project have  perceived that soil erosion in their plot is significantly more severe than other schemes (X2, 198.3). The comparison based on aggregated values shows that the Argeda 01 and Gedemso 01 irrigation projects have environmentally performed better than the Eballa and Bedene Alemtena irrigation projects.DOI: http://dx.doi.org/10.5755/j01.erem.63.1.3401