The Reuse of Sediments Dredged from Artificial Reservoirs for Beach Nourishment: Technical and Economic Feasibility

Sedimentation has significant impacts on the useful capacity of an artificial reservoir, a resource to preserve. Interventions of dredging are therefore often unavoidable, even because decommissioning of dams is often impossible in many contexts and entails high costs. Dredging generates an undesired accumulation of materials that represent an environmental cost, but that could be used as intermediate products in other processes, such as beach nourishment. The study develops a method for the evaluation of the feasibility of an investment aimed at coastal nourishment with sediments dredged from artificial reservoirs. The method considers the set of technical conditions that make such use possible. The presence of economies of scope, with environmental diseconomies utilized as joint product, modifies the evaluation approach. The results of the approach show a possible environmental and economic sustainability of the proposed investment even in the presence of highly unfavorable scenarios. The study applies the feasibility appraisal to the case of the Guardialfiera reservoir in Molise, Italy.