In the Mediterranean area, climate change increases significantly the water needs by crops while water resources are getting scarce because of reduced and distributional shifts of rain patterns. The need for methods to identify and assess robust adaptation strategies are urgent. Combining a multistakeholder dialogue and agro‐hydro‐economic modelling we aim at addressing this question. Based on an experiment conducted in one of the most overexploited water basins in France, the Aude catchment, we propose an approach to co‐construct strategies for climate change adaptation of the farming sector and water management with a multi‐stakeholder dialogue and modelling. Local scenarios derived from Socio‐economic pathways (SSPs) are co‐constructed as narratives that detail context, local economy, agricultural development and, water management and governance. The quantification – partly done by stakeholders and partly enabled by agronomic modelling ‐ enables to state that the difference in the effect of land use changes (socio‐economic scenarios) are much higher than the ones associated to alternative climate scenarios. This work is still in progress, but already shows a very good and active level of participation of key stakeholders.