Factors affecting the effectiveness of Runoff Harvesting Dams in Nepal

Abstract

The objectives of this study were to measure the level of effectiveness and analyze the factors affecting the effectiveness of runoff harvesting dam projects that have been implemented in Dhanusha district of Nepal as an activity of watershed management. 25% or 6 sampled runoff harvesting dams and a total of 71 sampled households representing the water user groups were taken in to this study. A questionnaire for household interview, check list questions for key informant interview and checklists for desk review and field observation were administered covering the variables of effectiveness indicators and factors. The data were analyzed by applying scoring and ranking, descriptive statistics and factor analysis method. It was found that 3 runoff harvesting dams were highly effective and 3 were moderately effective. Highly effective runoff harvesting dams show positive changes in all indicators; increased water availability for irrigation, household use and livestock; decreased soil erosion and disaster; improved moisture retention and microclimate; increased agriculture and forest production; increased household income and enhanced capacity of water user groups. Moderately effective runoff harvesting dams do not bring positive changes in water availability for irrigation; bank cutting and deposition; agriculture and forest production; and household income. The levels of effectiveness of runoff harvesting dams are significantly correlated with the factors upstream management and operation and maintenance at 0.01 levels. It is not significantly correlated with Location, soil type, siltation, participation, conflict of objectives and budget allocation. Thus, the levels of effectiveness of RHD projects are greatly influenced by upstream management and operation and maintenance factor. It is suggested that RHD projects should be implemented following principle of participatory integrated watershed management and development with multiyear plan (at least 3 years) to enhance the level of performance of upstream management and operation and maintenance factor so that level of effectiveness of RHD projects can be increased.