Social and governmental influences when engaging in citizen participatory water quality monitoring in lower middle-income countries (LMICs)

• Awareness gaps between pollution facts and public assumptions were observed. • Citizen participatory water-quality monitoring can be effective in addressing these gaps. • The human five-sense assessment was applicable to evaluate pollution levels. • Positive interactions between citizen participatory and obligatory water-quality monitoring were identified. • International cooperation should be designed considering local perceived costs and benefits. In many lower-middle-income countries, rapid urbanization and high population growth severely affect domestic wastewater pollution in urban water bodies. Thus, it is imperative to consider not only the technical but also the social and governance aspects of promoting key countermeasures, such as wastewater treatment plants, for which social acceptance is required. Interventions through an international cooperation project in the Rocha River Basin in Bolivia clarified the awareness gaps related to water pollution, applied citizen participatory water quality monitoring using a human five-sense assessment method, and achieved reasonable awareness changes and adaptable local activities. However, existing studies on the relationship between citizen participation and adaptable local activities from the perspective of local governments with limited resources and interventions in international cooperation remain unknown. Here, the validity and applicability of this method with citizen participation and its success and limitations were evaluated, considering technical, social, and governmental aspects as well as government-perceived costs and benefits related to decision-making. The results revealed that this method has adequate validity and potential to promote effective awareness among citizens. Furthermore, positive interactions between citizen participation and obligatory water quality monitoring were identified as factors for continuous local activities. These findings provide an adequate design and approach for international cooperative interventions in lower-middle-income countries with limited resources.