Navigating water security: A sustainability evaluation in basin socio-ecological systems. The Grande River basin case study, Antioquia-Colombia.

Socio-ecological sustainability arises from interactions between natural and social systems. Sustainability in water security means effectively managing water resources to continuously achieve social goals without surpassing ecological limits to maintain or enhance ecological integrity and social well-being. Despite efforts to measure sustainability focused on water security, challenges remain, such as selecting indicators that capture socio-ecological dynamics and defining appropriate aggregation methods. This manuscript proposes an operational framework for evaluating socio-ecological sustainability and demonstrates its application through a case study in the Rio Grande Basin (Colombia) in response to such challenges. The operational framework was built based on a literature review on existing frameworks and socio-ecological studies, identifying their potential and capacity to measure the components and variables of an existing conceptual framework. For the calculation, the basin was divided into four zones based on social organization, with a single value derived using four aggregation methods: simple average, weighted average, minimum value, and maximum value. As a result, the framework determines sustainability status using set-indicators representing analysis components, each composed of partial-indicators measuring natural and social system variables. The findings for the basin indicate that it is strongly unsustainable under the first three methods and unsustainable in the highest value of the four zones. This strong unsustainability is due to a lack of ecological integrity (poor erosion control), limiting hydrological functions crucial for water security. Additionally, there is inadequate access to water and sewerage services, and dissatisfaction with water demand, affecting community needs. These assessments may inform decision-making for territorial planning and management. In the study basin, actions targeting erosion control (reforestation, efficient soil management) and enhancing physical and social capacity (service coverage, participation) will promote sustainable management, ensuring social well-being and ecological integrity. This assessment also identifies drivers for transitioning to sustainability, fulfilling water security objectives.