The tool and the viewer: Plurality of values and hydrological modeling in the Huasco river basin

Understanding the connection between plurality of values and ecosystem services, is essential for decisions regarding nature management with a justice perspective. Therefore, it is essential to examine whether approaches to modeling and valuing ecosystem services for national policy adequately incorporate intrinsic and relational values. Chile is using a semi-distributed hydrological modeling approach for water management and climate adaptation policy and planning in over one hundred basins. This study evaluates the capacity of this hydrological modeling tool to integrate plural values associated with ecosystem services in watershed planning. The empirical analysis focuses on the Huasco River basin in northern Chile, where 48 water-related ecosystem services and plural values were identified through semi-structured interviews with 201 residents. Interviewees elicited the underlying reasons for their valuation, and categorized into value types and statistically analyzed them using Chi-square tests and logistic regressions to explore associations with demographic variables.Twenty-four most frequently mentioned services were selected for discussion with ten hydrological modeling experts involved in national policy planning. While consensus emerged around the feasibility of modeling 13 services primarily those linked to instrumental values, experts expressed uncertainty regarding services tied to relational and intrinsic values, such as “scenic beauty” and benefits from “water sound”. Findings revealed that instrumental values are more readily captured by existing modeling approaches, whereas relational and intrinsic values face methodological constraints. This results in two key limitations: (1) a reduction in the diversity of values considered in planning, and (2) possibilities of environmental injustices in the process. The study underscores the need to expand modeling frameworks to accommodate non-provisioning values and to critically reflect on the epistemological foundations of water governance.