Acceptance of sustainable water management solutions (ranging from decentralized
wastewater treatment systems to individual conservation behaviors) remains a
challenge, particularly in regions where water scarcity is not perceived as an issue.
Drawing on a series of qualitative, experimental, and applied studies conducted in Spain
and the Netherlands (focus groups, interventions, and surveys with over 900
participants), our research highlights key psychosocial mechanisms that can either
hinder or foster engagement with sustainable water practices. First, we found that
without recognizing a need for change, alternatives are unlikely to be considered. A
systematic review and a focus group study in Galicia (Spain) (N=18) showed that
perceived scarcity and environmental threat are the first step for acceptance. However,
making the problem cognitively accessible before presenting the solution significantly
improves how these systems are perceived. This was supported by an experimental study with university students (N=287), showing that priming environmental concern
increased positive attitudes (even when disadvantages were acknowledged). A threephase
intervention in a business center with an operational decentralized plant combined
a focus group (N=6), environmental priming (N=46), and a participatory session with
experts (N=25). Results showed that inclusive processes and identity-based framing
reduce initial resistance. A follow-up cross-national experiment (Groningen, N=92;
Santiago de Compostela, N=208) showed the positive effect of framing these
technologies as bottom-up initiatives aligned with pro-environmental identity. Finally,
we introduce Metaperception (how individuals believe others evaluate their proenvironmental
behavior) as a promising construct for understanding social image in
sustainability. This scale, developed and validated in the context of water conservation
(Spain, N=231; N=384), showed strong predictive power for both intention and
behavior, and offers new insights for broader applications in environmental
engagement.