Small-scale Hydroelectric Power for Developing Countries: Methodology of Site-selection Based on Environmental Issues

Abstract

Small Hydropower Projects (SHPs), defined as including hydroelectric generating facilities with capacities of 1,000 kW or less, have great potential for elevating the standard of living and contributing to the economic growth of isolated rural communities especially in Third World countries. However, construction and operation of an SHP can result in adverse environmental impacts that should be assessed in the initial stages of site-selection and avoided in the development.Environmental concerns can be factored into a site-selection process both at the screening and feasibility stages. The screening study is the process by which a large number of potential sites are reduced to a much smaller number of candidate sites based on coarsegrained engineering, socio-economic, and environmental, criteria. Although many of the factors determining the suitability of a given site at the screening stage involve basic engineering or economic questions, fundamental environmental issues that should be addressed include an appropriate resource-development strategy to accompany the SHPs, the quality and quantity of water available for all project needs, the presence of near-by protected areas, habitats, or important species, and the adequacy of local support for environmental protection requirements of the project.The feasibility study is the final stage of site selection, where a relatively small number of candidate SHP sites are examined in proper detail and the best are selected for development. Potential environmental impacts of SHPs range from flow-disruption downstream to the spread of water-borne diseases and parasites, and are related to the design and size of the facility. We provide a check-list of environmental data that should be collected at this stage in order to judge the significance of projected impacts of candidate SHPs.It is important that site selection and impact evaluation be conducted by competent individuals with formal training and experience in an appropriate environmental field. After compiling relevant information (e.g., through literature searches and contacts with government agencies or universities), the feasibility study team should visit the site of each at all likely-to-be chosen SHP. This will allow the interdisciplinary team's members to identify any previously unanticipated problems, to receive inputs from the local community, and to weigh the various benefits and consequences of SHP development before making their final selection.