Supporting decision-making for channel conveyance maintenance

Abstract

Channel maintenance activities, understood as vegetation and sediment management, have a potential to change the conveyance capacity of a watercourse and thus, to provide a benefit from a flood risk perspective. Vegetation and its overgrowth is one of the main factors influencing flow capacity and hence river conveyance. Despite the undesirable consequences associated with flooding, it is rare that sufficient funds are available to undertake all necessary maintenance activities. In the face of limited budgets, flood risk managers must take difficult decisions in order to decide how and where limited resources should be invested. This paper presents a national scale approach to identify the strategically important watercourses where conveyance related works produce the greatest benefit. This is done by identifying watercourses where maintenance works may have a potential to positively maintain or increase conveyance capacity and watercourses where the attribution of area or receptors benefiting is important. Assembling together this information produces a picture of the strategic lengths of watercourse to be maintained.