Cooperation under conflict: participatory hydrological modeling for science policy dialogues for the Aculeo Lake

Hydrological modeling tools can support collaborative decision processes by visually displaying hydrological systems connections, uncertainties, as well as conflicting preferences over water management strategies. Nevertheless, many challenges remain in the real application of these technical tools to successfully implement, capture, and communicate with non-experts the complexities of coupled human hydrological systems. A 5-step process shows how a WEAP-based hydrological study aiming to explore the disappearance of a 12¯km2 lake in the Aculeo basin in Chile was transformed into a multiple question-driven sociohydrological modeling process to help answer the diversity of questions instigating conflict. Collaboration allowed construction of a surface-groundwater hydrological model that responded to local stakeholders' uncertainties. While testing a subset of socially accepted management strategies under two climate change scenarios, combining the strategies allows recovering up to half the lake water volume. However, the 5-step participatory modeling process also shows how the increasing social-environmental conflicts over the causes and effects of the water scarcity are challenging barriers to overcome with modeling tools. As presented in this article, although flexible approaches and research agendas could better support the exploration of synergies towards collaboration and production of useful and socially acceptable hydrological models, there are still value-driven aspects of water management that need to be explored to better support science policy dialogues.