Executive Summary: San Pedro Sula - Honduras Urban Flood Risk

In this report, flood adaptation measures were analyzed for selected districts in the municipality area of San Pedro Sula based on cost-efficiency criteria for adaptation/risk reduction using the The Economics of Climate Adaptation (ECA) framework. The top three measures identified were: a.“Vegetated Swales”, b. “Refurbished Collectors”, and c.“Ecological Restauration”. The Economics of Climate Adaptation (ECA) framework is set out to develop practical recommendations that enable national and local decision-makers to build a comprehensive assessment of the climate risk that their economies are facing while minimizing the cost of adaptation through cost-efficient strategies. A particular emphasis is made on a robust and integrated approach based on sound scientific facts. The ECA as applied here contains three elements supported by the modelling platform CLIMADA: 1. Climate risk identification: Conduct an identification of climate risk in a defined region (e.g. urban area), identify areas and people at risk, spanning all significant climate hazards and the full range of possible impacts for different sectors 2. Climate risk quantification: Calculate the expected damage across multiple climates and economic scenarios 3. Identification and prioritization of CCA measures (using Cost-Benefit Analysis of CCA measures): Determine strategies including a portfolio of specific CCA measures with detailed cost/benefit assessment. Additionally, ECA includes a strong component of stakeholder engagement to complement the hazard modelling and asset valuation. In its first part, this report recalls the scope of the study that was agreed on in coordination with all stakeholders regarding the areas of the municipality to be included, the scenarios (climatic and economic) to be applied, and what assets should be impacted. During several workshops and webinars, a portfolio of measures (from a longlist to a shortlist) was discussed and later modeled. Values have been validated by stakeholder's concertation and expert interviews. Further, this report presents a brief overview of ECA and the main results of flood impact today and in the future using CLIMADA, a probabilistic modelling platform. By 2042, even in a moderate climate scenario flood damages in the municipality are expected to rise by over a 100% in San Pedro Sula, due both to economic growth (assets will be more valuable) and climate change (hazard will be more frequent and more intense).