This study explores the consequences of the non-adoption of genuine participatory development communication approaches on the sustainability of water supply systems in Adiyan, Akute, Iju, and Isashi communities in Ogun and Lagos States, from where raw water is pumped, treated, and distributed for consumption in Lagos State, Nigeria. It is anchored on Participatory Communication Theory, a multi-track theory developed by Paulo Freire. A mixed methods design was adopted for the study, and this involved the quantitative technique of questionnaire administration and the qualitative technique of in-depth interviews with 50 participants. The study found that the systems’ developer did not generate feelings of local ownership among host community stakeholders to motivate them to become involved in the projects’ sustainability. It recommends that the developer should set up a host communities’ dialogue office to engage in horizontal dialogue with community stakeholders to assess their needs and ensure their involvement in the sustainability of the water supply systems.