In spite of the significant contribution of small scale irr igation towards food supply andrnemployment creation there are enormous factors that challenge efficiency as well as theirrneffectiveness.rnThe purpose of this study is to identify major constrai nts for the effectiveness of existing smallrnscale irri gation schemes based on Batu Oegaga Communal Small Scale Irri gation in the upperrnA wash valley.rnThe study employed both qualitative and quantitative methods of data generati ng and analysisrntechniques.rnIn the study it was found that 57. 1 % of the targeted area is not totally irrigated because ofrndeficiencies in planning and designing that didn't take into account the topography and pumprncapacity to deliver sufficient water.rnBinary logistic was applied together wi th descriptive methods to analyze the survey data inrnidenti fy ing and measuring household level determinants of effectiveness of small scalernirrigation schemes. The model categorized improved irrigators and not improved irrigators duernto the irrigation project in 86% of the cases correctl y. Out of the 16 hypothesized variables tenrnof them increased the probability of improvement of household 's li vi ng standard after irrigationrnas expected. Four of the variables including number of oxen possessed by famil ies and level ofrnoutput from rain fed production are found stat isticall y significant. Proper planning andrndesigning of small scale irri gation is paramount. Emphasis has to be given for land preparation.rnProvision of credit service for purchase of inputs and covering expenses related to irrigationrnpractice are areas of intervention.