Sustainable development is implemented not only at the global level, but primarily in local environments. Shaping the space of river valleys becomes particularly important in the face of climate change and growing water deficit. The article therefore addresses the issue of the social perception of water management in the context of climate change. The aim was to answer the questions: what is the social awareness of water management in the face of climate change, and what sustainable solutions are socially accepted? The research was carried out in the south-eastern part of Poland, in the Podkarpackie and Lublin voivodeships. The diagnostic survey method, an original survey form, and the CAWI technique were used. The study group analyzed the perception of global, negative megatrends, and challenges related to water retention in the context of climate change. The task was to identify respondents’ awareness of new sustainable management methods in river valleys. Due to the fact that the studied area is largely agricultural, differences in the perception of the studied items were sought, depending on the place of residence. It was assumed that inhabitants of rural areas have greater contact with nature, which may change their perception, and differences were looked for depending on the region of residence. Differences in the perceptions of the studied phenomena were also searched for, depending on the respondent’s sex. The calculations show that the place of residence (urban–rural) and the regions (Podkarpackie–Lublin voivodeships) do not differentiate the perceptions of most of the examined items. However, sex primarily affects the perception of global megatrends and the perception of climate change. The results indicate the respondents’ lack of awareness about natural forms of water retention. Respondents expected the implementation of outdated technical forms of flood protection. Expectations focused mainly on flood embankments and large dam reservoirs. There was strong belief among respondents regarding global megatrends and their impacts on social and economic life. A knowledge deficit was identified in relation to sustainable management methods in river valleys that favor water retention.