*4.2. Preliminary Assessment of Adaptation Measures in Practice*

After defining the strategies and their respective measures, CEA and co-benefits were estimated, following the methodology described above. The variables used as an input in the CEA were the results of the hydrodynamic models and annualized costs estimations, whereas the co-benefits scores were obtained by participatory processes of multidisciplinary experts in Barcelona and Bristol. The ranking results of the preliminary assessment in Barcelona and Bristol are presented in Tables 5 and 6 respectively. Weights given to each indicator were determined under consensus during the second workshop, following stakeholders' judgement.


**Table 5.** Preliminary ranking results for the adaptation measures included in the flood and CSO strategies assessed for the Barcelona case study.

**Table 6.** Preliminary ranking results for the adaptation measures included in the pluvial and fluvial strategies within the central area of Bristol.


Table 5 presents SUDS measures as the preferred option, followed by structural measures for both strategies. The equal distribution of weights between indicators implies that those with larger indirect benefits are prioritized over the ones that are just more cost-effective. The reinforcement of the stability of waste containers is the second option for the floods strategy, and the early warning system for the CSO strategy.

Table 6 shows that demountable flood protection barriers are the most preferred measure for protection against pluvial flooding and for fluvial and tidal flooding, combined in this instance with riverside defense walls that offer protection up to a 1 in 200-year event (ranked second). For the Ashton Vale region (Appendix A), a wider range of measures were selected to offer improved protection against pluvial flooding and reduce CSO spills events.
