Work

Sea level rise and storm surge impacts economic assessment on coastal infrastructure: Study case of the Llevant Main Sewer (Badalona, Spain)

Year: 2026

Type: article

Abstract: Coastal wastewater infrastructure is increasingly threatened by climate-induced hazards, yet quantitative risk assessments for such systems are still limited. This study evaluates the climate risk of the Llevant Main Sewer, a 10.8 km coastal-parallel sewer serving approximately 400,000 inhabitants in the eastern part of the Metropolitan Area of Barcelona (Spain), under four Shared Socioeconomic Pathway (SSP126, SSP245, SSP370, SSP585) scenarios up to 2100. Hazard assessment was based on significant wave height and sea level rise projections derived from CMIP6 climate models, propagated to the sewer alignment using a linear coastal approach calibrated against the Barcelona buoy. Exposure and vulnerability were characterised through a Protection Level Index (PLI) that classifies sewer sections by their degree of coastal protection. Vulnerability functions relating repair cost per linear metre (€/ml) to storm surge intensity were developed from historical intervention records along the main sewer, providing novel empirical cost estimates that are scarcely documented for this type of infrastructure. Integrating these three components, economic risk was estimated under Business-as-Usual scenario in which repairs are triggered only after storm-induced failure. A Cost-Benefit Analysis (CBA) comparing three adaptation strategies (damage repair, rock revetment enhancement, and layout relocation) was performed across all SSP scenarios. Results show that risk grows substantially under higher-emission pathways, with layout modification yielding the most favourable benefit-cost ratios for most scenarios. This framework provides a replicable methodology for assessing and managing climate risk in coastal sewerage systems, with direct impactions for infrastructure planning in other Mediterranean and coastal urban contexts.

Source: Ocean & Coastal Management

DOI: 10.1016/j.ocecoaman.2026.108244

Authors: Guillem Flor Tey, Joan Insa, Eduardo Martínez-Gomariz, Beniamino Russo, César Mösso, César Paradinas

Institution: Universitat Politècnica de Catalunya

Language: English

Topic: Coastal and Marine Dynamics

Subfield: Earth-Surface Processes

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Industry, innovation and infrastructure, Sustainable cities and communities, Climate action, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $4,350