In principle Nepal’s hydropower potential is impressive due to rugged mountain terrain from which snow and rain fed rivers produce significant amount of seasonal water flow. Owing to this natural hydrological processes, Nepal projected an image since 1970s that this country has one of the richest hydropower potential in the world through which the country would be able to alleviate poverty by bringing socio-economic transformation of the Nepali society. This potentiality was compared with the wealth of some oil-rich Gulf countries. After 40 years, the country is still struggling hard to meet the domestic energy demand, and the once popular national slogan that ‘Nepal is rich hydropower potential with 83000 MW’ is no more exist. Completed in late 1980s, Kulekhani hydro electricity plant (KHEP) became a showcase example of hydropower development, which is the first and only reservoir based hydropower plan in the country. A strong cloudburst of July 1993 seriously hit the plant as its penstock pipes were swept away and seriously reduced water holding capacity of the reservoir due to sediment deposit. In the project design document, such risks were ruled out and, the watershed has been identified as one of the safe zone from any extreme climatic events. The event had a huge impact on the other projects under pipeline. Since then 18 years have passed but no new reservoir-based hydropower plants are built. This is a rationale behind selection of KHEP as a study site for this case study.
In the context of growing impacts of climate change on water bodies and hydrologic cycles, study on prospects of reservoir based hydropower in Nepal are highly desirable. Storing water in reservoir is one of the globally recommended options to tackle climate change impacts on hydrologic cycle. In this case, the reservoir based hydropower that accumulates water during rainy season and produces electricity throughout the year, is one among the best options to address the current problem of seasonal power shortage. Even though, various reports has suggested further study on this sector, in Nepal, the effects of climate change on this valuable resource remain questionable.
This study mainly focuses on the hydrological and weather time series data in relationship with discharge, level of water in the reservoir and energy generation,. With the allowable 4 % error level, 30 years of rainfall data from 1980 to 2009 of nearby rainfall stations were analyzed. Findings show that, Kulekhani receives 78% of rainfall during monsoon (June-September), the water accumulated during t Read the rest of this entry »