People perceive the importance of ecosystem services in different ways, depending on their values, beliefs and needs. This study provides a nuanced understanding of the multiple ways stakeholder groups perceive the benefits derived from hydrologic services in the surrounding area of the "Gialova" coastal wetland in Messenia, Greece. The social-ecological system of this region depends on a steady flow of water-related ecosystem services and livelihoods are closely linked to agriculture and tourism. At the same time, these activities, along with climate change driven weather extremes, could affect regional water quality and availability. The objective of the study is to understand the stakeholders' key viewpoints on water-based ecosystem services (WES) and provide contextual information regarding the drivers affecting the identified WES. A "value pluralism" lens is applied to capture the multiple dimensions of values expressed by the participants of the study. The study's primary method is "Q-methodology", a participatory mixed-methods approach suitable for eliciting patterns of valuation that are held in common within a group. Thirty-two stakeholders participated in the study and the analysis highlighted five key perspectives, titled "Basic needs first", "Us vs. them", "Tradition and history", "Modern environmentalists" and "Ecocentric". The results indicate different perceptions of the importance of WES, alongside a range of multiple explanations of why the WES are important. The five perspectives were compared and they reflected divergent understandings of i) the nested nature of socio-ecological systems, ii) spatial perception of ecosystem services and, iii) trade-off between relational and instrumental values. The points of consensus and disagreement among the participants along with their perceptions of drivers of change, suggest promising leverage points for sustainable and inclusive water resource management. In addition, this empirical case study contributes methodological insights to the ecosystem services socio-cultural valuation body of literature.