4.3.1. Selection of Adaptation Scenarios

Results from the first ranking exercise gave stakeholders insights on the advantages and disadvantages of the measures proposed. This facilitated the discussion regarding the selection of the most relevant measures to include in the adaptation scenarios, aimed to answer different policy questions. For example, in the case of Barcelona's strategy for pluvial flood impacts reduction, there was a clear interest from policy-makers in the co-benefits provided the SUDS measures, while technical experts highlighted the potential reduction of risks and recovery time offered by the structural measures, although the costs of the latter were high and therefore difficult to meet. Therefore, they decided to assess the potential impact of implementation of SUDS across the entire city, while the structural measures were divided by zones. Adaptation scenarios were created to obtain results for those requests (Table 7). Regarding the stability of waste containers, detailed assessment was not found relevant, as the preliminary assessment already displayed a low CEA result, which was enough to be included in the new Climate Action Plan for Barcelona.



In the Bristol case study, the needs of stakeholders guided the way adaptation strategies were categorized (Table 8). City council representatives were most concerned with fluvial flooding linked to the River Avon, its associated watercourses and tidal interactions of the Severn Estuary, alongside pluvial flooding originating from extreme rainfall across the urban area. The interest was again on gaining knowledge on the zonal assessment of the city, although structural measures were identified as the most promising interventions. Due to restrictions in budgets, the Bristol case study chose to investigate only the use of property level protection, since it allowed adaptation measure assessment using previous flood modeling.
