This measure is usually carried out in form of sets of barrages built in a direction perpendicular to a stream’s direction. The aim of the measure is to modify the erosion and accumulation processes in torrent streams through the retention of water and eroded material, e.g. when settlement areas are at risk. It effect is enhanced when applied together with other measures in the watershed. The material used for the barriers depends on the natural conditions of the area of interest and on hydro-technical calculations. Permission by water management authority and nature conservation authority may be required.
