Sahilu, Geremew (PhD)Israel, Fiseha2018-06-182023-11-282018-06-182023-11-282014-04http://etd.aau.edu.et/handle/12345678/1308Ensuring functional sustainability of water and sanitation developments throughout the design period is vitally necessary. It helps to identify the main causes of non functionality and indicate the troubleshooting for non functionality per scheme system components at the stage of design, construction and service period. To identify the major causes of non functionality the research has employed both primary and secondary data sources. Secondary data was collected from respective governmental and non-governmental organization at federal, state and woreda level. Primary data, on the other hand, was obtained using questionnaire, Focus group Discussion (FGD) and observation. Data from the secondary and primary sources enabled the researcher to scan and investigate more than 95 % of water and sanitation schemes in Chencha woreda rural areas. The common rural water and sanitation technologies include hand dug well, shallow well, spring with gravity distribution, spring at spot and simple pit latrine. All have been studied and evaluated for their cause of non functionality. The research found that 87 % of non functionality occurred before its estimated design period, which is within ten years. But the average non functionality occurrence of the schemes is between six years up to seven years. The most common non functionality causes are poor design, below the standard construction and poor institutional set ups of water and sanitation infrastructures. It includes: spring capping failure, management and financial problems, construction materials problems, source yield decreasing, poor quality of water, pumping system failure, poor quantity of water and pipe line failures. Water and sanitary schemes are functionally sustainable, only when social, financial, technical, institutional and environmental factors are integrated with every project life stages. The stages are needs assessment, conceptual design, design and action planning, implementation, and operation and maintenance. To get rid of non functionality every system component design and construction activity should be in accordance with the applicable design and construction methods. All respective governmental, nongovernmental and community stakeholders should carry out responsibility for functionality and sustainability of water and sanitation schemes. It is impossible to meet the functionality of water and sanitation schemes developments, without the integration of all respective bodies in all project life stages through feasibility study, designing, construction and service periodsenSouthern EthiopiaThesis