Valuation of the ecosystem services of beach nourishment in decision-making: The case study of Tarquinia Lido, Italy

• CBA is used to assess financial and economic benefits of a nourished beach in Tarquinia Lido, Italy.
• Net social benefits are higher than the beach generated income even if negative externalities are considered.
• Benefits allocation to local gainers reduces free riders, internalising partially cost of beach maintenance.
• Internalising environmental costs might require the adoption of charges or subsides such as PES.

Cost Benefit Analysis (CBA) is a systematic process commonly employed by the US Army Corps of Engineers (USACE) to assess primarily benefits stemming from storm damage reduction and recreation enhancement by beach protection. The USACE goal is to quantify federal money disbursement to local communities to counter the consequences of coastal erosion. The EU has recommended the use of CBA for shoreline management (both at regional and local scales), looking not only at the financial aspects of project assessment, but also at non-market benefits (ecosystem services of the beaches) and environmental costs, assessed on a broad time horizon in a given sediment cell. In this paper, several ecosystem services provided by beach protection are considered and some of them monetised to assess the local net benefits of a nourishment project carried out along the Tyrrhenian coast of Italy. The paper shows that free riding emerges by the public supply of coastal protection, and that it could be possibly partially removed charging the cost of beach maintenance to the local users. In addition, supply of coastal protection may generate negative environmental externalities. However, costs of environmental damage of the beach nourishment are not easy to be internalised. This suggests alternative market mechanisms (charges or insurance premiums) to reduce the development pressure on coastal areas subject to high rates of erosion or to explore the adoption of subsides such as payments for ecosystem services (PES) at seascape scales.