Reductions in water availability and increasing rainfall variability are generating a narrative of growing competition for water in the Mediterranean basin. In this article, we explore the distribution and importance of water resources in the Muga River Basin (Catalonia, Spain) based on key stakeholders’ perceptions. We performed a sociocultural evaluation of the main water ecosystem services in the region through stakeholder interviews and participatory mapping. The basin was generally perceived as a hotspot of ecosystem services, but we detected varying opinions and considerable differences in the perceptions of importance and spatial distribution of water ecosystem services. These discrepancies were linked to the varying levels of stakeholders’ dependence on water. Our findings are important for contributing to correct water planning and management in the river basin, which is a complex water social system marked by conflicts between different stakeholder groups vying for the same resource. This complex situation requires bottom-up strategies to create transparent, participatory decision-making models.

Power relationships, access and control, (in)equity, and (in)justice are key modulators of conflicts arising from ecosystem services between multiple stakeholders. A greater knowledge of stakeholder value systems and behaviors is crucial for understanding socioecological dynamics. We propose an analytical framework that combines political ecology and game theory to analyze water ecosystem services. This integrated framework was used to reinterpret concepts such as common goods, (a)symmetric flows, and (un)fair trade-offs in the context of ecosystem services. The purpose was to gain a better understanding of behaviors and (a)symmetries in power relationships between multiple stakeholders. We studied the case of a north-western Mediterranean river basin using data obtained from stakeholder interviews and newspaper articles. Our findings uncovered different types of stakeholder relationships, ranging from mutual support and cooperation to conflict. The proposed analytical framework shows how social mechanisms can affect ecosystem services flows, potentially facilitating or hindering the development of more equitable management models for natural resources.