1 ECONOMIC SUSTAINABILITY OF INTEGRATED HYDROPOWER DEVELOPMENT OF ERO-OMOLA FALLS, KWARA STATE, NIGERIA. LAWAL KOLA MAROOF 1 1 Catchment Director, Nigeria Integrated Water Resources Management Commission, Abuja, Nigeria. BOLAJI FATAI SULE 2 2 Director, National Centre for Hydropower Research and Development, University of Ilorin, Ilorin, Nigeria. OGUNLELA AYODELE.OGUNLELA 3 3 Agricultural and Bio-Systems Engineering Department, University of Ilorin, Ilorin, Nigeria. Economic sustainability of integrated hydropower development of Ero-Omola Fall was investigated in compliance with Hydropower Sustainability Development Protocol (HSDP) developed by International Hydropower Association (IHA) in 2004. Field work was carried out to obtain primary data like streamflows, sediment characteristics, petrographic information, water quality, water quantity demand, hydropower load demand and land topography. Economic optimization of hydropower generating potential of Ero-Omola Fall, integrated with water supply, irrigation and drainage was carried out based on the data obtained from the field work. The potential hydropower of Ero-Omola Water Fall was estimated at 8.0MW, Water supply to communities is estimated at 18 Mm 3 /day, irrigation water for Fadama farmers at 2.2 x 10 6 m 3 and ecological water release of 0.0504 x 10 6 m 3 were also derivable from the scheme. The modified internal rate of return for hydropower, water supply and irrigation yielded the highest returns of 13% on capital, while hydropower alone yielded 5%. The NPV of cumulative generated cash flows is positive, which indicates that the project would not operate at a loss. The findings also showed that, the sustainable conjunctive use of hydropower releases is the most sustainable mitigation measures against seasonal flooding downstream of the proposed hydropower plant. The study has established a rational basis for the assessment of a typical medium scale hydropower plant which could be adopted for similar locations in Nigeria. Keywords: Integrated Hydropower, Sustainability, and Engineering Economics.