Appraisal of Methodology in Estimating Irrigable Areas and Processes of Evaluating Feasibility of NIA Irrigation Projects

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Irrigation has perennially accounted for the major expenditure outlay of the Philippine government in the agriculture sector. The performance of the national irrigation program, however, has always been below expectation. This Policy Note highlights the key findings of a component study of the rapid appraisal of the irrigation program commissioned by the National Economic and Development Authority and the Department of Budget and Management to the Philippine Institute for Development Studies, to provide input to the budget process. The study indicates that the NIA irrigation systems in general have various technical problems and issues that need to be resolved. One of these issues is that the actual irrigated areas in all four irrigation systems studied had been consistently below the target or design irrigation area. This is due to overestimation of irrigable areas by not fully accounting for built-up areas or urbanization, flooded areas during the wet season, and elevated areas that cannot be reached by gravity.