The supply of reclaimed water to ecosystems increases their ecosystem service flows, which is directly translated into terms of social welfare. This study explores the factors that determine the different perceptions of the welfare impact of supplying reclaimed water to different, and competitive, ecosystems in the Segura River Basin (southern Spain): specifically, an agroecosystem (agricultural irrigation) and a river (higher river flow). The results of a contingent valuation exercise with the population of the Murcia Region show four different groups of respondents, depending on their willingness to pay (WTP) preferences. The factors that identify differences among welfare impacts are the age, the gender, the education level, the monthly income, the nearness of the household to the river, and, above all, the degree of satisfaction with funding of water reclamation. This study broadens our knowledge of individuals' heterogeneous preferences in water reuse options, which is crucial for policy makers in the development of socially accepted and sustainable water resource management strategies.