Satoshi Hoshino

The intrinsic relation between water and energy has made the water–energy nexus a burgeoning issue in the discussion of sustainable development. Recently, research has begun to pay attention to stakeholders in the nexus. They, however, identified stakeholders as a given without employing methodically scientific processes with rigorous parameters. Filling in the gap, this study presents a heuristic approach to identifying critical stakeholders of multi-actor systems in the water–energy nexus. It involves three sources of influence (social roles, specific concerns, and key problems) along with four other boundary issues (motivation, control, knowledge, legitimacy), forming a matrix of the boundary categories of Critical Systems Heuristics (CSH). This study applied the heuristic analysis to the project of floating photovoltaics installed in a pond in Hyogo, Japan, as the case study. It is a unique case of the water–energy nexus since the location of the floatovoltaic installation is a privately owned pond that is also part of the public landscape and an irrigation source for the surrounding agricultural areas. The results identified two macrogroups of stakeholders (residents and project developers) driven by general interests in the project. They were derivable as overlapping micro-actors interested in more specific issues related to different facets of the project. Overall, conflicting interests in the multi-actor systems indicated deadlocked interactions due to a multidirectional tug-of-war between the microgroups of actors. Conceptually, this study significantly contributes to the literature on the water–energy nexus and stakeholder management. Practically, the approach used offers scientific processes to understand the multi-actor systems and conflicting interests involved in/affected by the nexus, paving the way for more comprehensive resolution processes of water–energy conflicts.