Protection of river downstream of hydropower plant

Abstract

Frequent switching on and off of hydropower plant (HPP) turbines causes sudden water-level fluctuation in a river. If the plant is constructed on a lowland river in alluvial soils, the fluctuation provokes erosion of the riverbed downstream of the HPP and creates unfavourable conditions for water fauna and flora there. Legislative and common technical measures are often not sufficient to protect the riverbed against the harmful impact of the plant. This paper presents a new technique for protecting the riverbed from erosion and harm to water fauna downstream of a HPP. Attention is drawn to water plants (WPs), which have a strong influence on the river flow by slowing it down and increasing its depth. Possibilities to protect the river by means of WPs are analysed. Planting and growing of natural WPs in the river flow control spots have been found in practice difficult to be performed. Natural WPs are taken as prototypes for development of artificial ones. The flow-slowing ability of the latter is much greater than that of natural plants. Design of artificial WPs and their distribution in the river according to the requirements for the flow parameters are presented.