SEDIMENT BYPASS SYSTEM FOR IMPOUNDING RESERVOIRS.

Abstract

This study proposes the use of a pipe line system to transport the inflow sediment to a reservoir through the dam, and discharge it downstream. The system is powered by the available head at the dam. It aims at restoring the original sediment transport regime of the river (i.e. before the dam was built). The idea is fundamentally sound because of the much more efficient sediment transport characteristics of pipes compared to that of open channels. The necessary theory for the hydraulic design of such a system was simply not available and is developed in this study. The work of numerous previous investigators is summarized in the final results and in the developed equation which allows for the calculation of the capacity transport concentration of sediments in pipes. This equation, coupled with the most accepted head loss equation, and the continuity principle, allows for the hydraulic design of systems transporting grannular material. The calculation procedures were fitted into computer programs. In addition to computer programs, design charts where developed which allow for quick application as well as visualization of the developed concepts. It was concluded that the proposed system is fundamentally feasible. Although no economic analysis was conducted, indicators show that it is also economically favorable.