Socio-Hydrological Governance for Watershed-Scale Water Management Accounting for Various Agricultural, Municipal and Industrial Water Uses

Climate change is increasingly driving severe and prolonged hydrological droughts—even in humid regions—causing many rivers to shift from perennial to intermittent flow regimes. This trend is especially critical for agricultural watersheds like the Bécancour River basin (Québec, Canada), where expanding cranberry production intensifies water demand during vulnerable low-flow conditions. Addressing these coupled pressures requires capturing the feedback between streamflow and agricultural withdrawals, particularly given the complex reservoir management inherent to cranberry farming. This study presents an integrated socio-hydrological modelling framework to assess the co-evolution of cranberry farm expansion, water availability, and social constraints in the Bécancour River basin. We translate socio-economic survey data from cranberry producers into a System Dynamics (SD) model, capturing key feedback mechanisms related to economic pressure, social license to operate, conflict perception, and future expansion decisions. The SD model is loosely coupled with the distributed hydrological model HYDROTEL through a Python-based wrapper, allowing dynamic exchange between hydrological stress signals and socio-economic decision variables. The coupled framework is applied to explore scenarios, including climate stress, regulatory tightening, conservation-oriented policies, and technological adoption for water-use efficiency. Results highlight how social constraints and adaptive behaviors can significantly modulate hydrological impacts, emphasizing the importance of integrating human decision-making into watershed-scale water management models.