Result-based management tool for the assessment of existing structural flood protection and future planning. Case study in the Strymon River basin, Greece.

The occurrence of floods is a constantly increasing phenomenon which is associated with a series of environmental, economic and social impacts. Their valuation is inextricably linked to the loss of human life and material damage. The latter has a direct economic impact and requires financial resources to be repaired or reconstructed in order to continue to provide the required amount of protection in the future. The tools for assessing the financial cost of repairing damage or failure of technical/structural works constructed for flood protection are critical aids in flood project management by governmental authorities and public organizations responsible. These tools can provide spatial data linked to construction and repair costs for identifying problematic spots and areas that repeatedly show structural inability to prevent flooding. This leads to a flood risk assessment tool and can record information that supports decision-making procedures in order to formulate action and management plans related to flood planning.

In the case study area of Strymon River in Greece, the implemented flood protection and hydraulic structural works were recorded, with their spatial and descriptive information combined with failure repeatability, their initial construction costs and damage/repair costs. All data were imported in a web-based GIS tool that, through a methodological framework and after correlating other necessary information (flooding episodes, infrastructure, public networks, etc.), projected the economic cost of flood events by region, thus prioritizing the needs for additional projects or improvement actions, by forming different cost-benefit scenarios and a road-map for flood protection.