With the succession of heatwaves and growing difficulties in obtaining water in quantity and quality, water is at the centre of many tensions. Scientific forecasts are highly uncertain. Farmers are organising themselves around new water management infrastructures, while citizens are worried and make their concerns known. In western France, government consultation has led to the creation of water replacement reservoirs (also called as "megabassines" by their critics) (Carrausse 2022). These infrastructures enable surplus water to be stored in the water tables in winter, to be used when agricultural irrigation needs are greatest in summer. However, the social and environmental impacts are widely decried by opponents, backed by numerous scientists (Azam et al., 2023). Since 2022, there has been an increase in the number and variety of events linked to these protests, including demonstrations, juridical actions and damages to infrastructure. Many scientists are taking sides in the debate but are also committed to producing new data, whether this concerns the capacity of soils to retain water, the groundwater hydrogeology, naturalistic knowledge or legal remedies. From a STS (Science and Technology Studies) perspective, this paper aims to show how different narratives, including scientific narratives, participate in the fabrication of futures (Granjou, Walker, and Salazar 2017). I will show how farmers are placed at the heart of action in the face of the risks of climate change in the imaginaries associated with the implementation of these infrastructures and what alternative narratives are constructed.