EtO FRIENDLY MINI HYDROPOWER PROJECT: A CASE STUDY OFSRlPADAGAMA

Abstract

Sri Lanka is facing a severe crisis in meeting the growing power demand. Even though,small-scale hydropower is one of the best solutions to meet the increasing demand, suchprojects should be properly designed, evaluated and monitored. Acceptable modeling.techniques should be followed in hydrological studies within the framework ofsustainable development. Thus, this study was conducted to investigate the potential forestablishing a mini-hydropower in Sripadagama in Kalu Ganga in the Sabaragamuwaprovince in Sri Lanka.

A complete model that includes hydrological and economic components was developed.A detailed hydrologic investigation using liner- non-linear tank concept was carried outto predict the stream flow. Benefit transfer methods were employed to value theenvironmental losses due to the project such as deforestation, biodiversity losses,vulnerability of land slides, soil erosion, risk of dam failure and externalities. Theextended cost benefit analysis was employed to evaluate the eco-friendly nature of theproject.

Both hydrological and economical analyses show the viability of supplying 7.9GWblyear. The accuracy of predicting the stream flow at the dam site is 89.3%. Theeconomic analysis of the study show net present value of Rs. 932.7 mn, internal rate ofreturn 38% and benefit cost ratio 8.1. The results of the sensitivity analysis show that theproject is relatively less sensitive to changes in costs while more sensitive to changes inits benefits. Mitigatory measures and corrective actions particularly to geo-hazards aresuggested for sustainability of the project