Challenge of completing construction projects within the allocated budget, time and quality remain the biggest concern among project practitioners. Several approaches and tools have been developed over the past years to enhance the management of construction projects, yet projects dodge stakeholders’ expectations. This paper has identified social capital governance (relational controls) that are useful for managing and delivery of community-managed water projects. Social capital concept is acknowledged as an organizing logic that boosts project organizations and communities’ value. Thus, social capital is understood as people’s personal and impersonal connections in a project organization, their quality as well as common representations. Social capital facilitates the coordination and partnership of project participants. Nevertheless, the newness of this concept in the context of project settings and distinctiveness of varied construction projects trigger questionings regarding social capital governance’s representation and forms in project settings. A Quantitative approach was considered in addressing the emanating questions. A survey led to collection of data from 114 respondents, which enhanced the conceptualization of construction projects’ social capital. The findings showed that collective responsibility, trust, member commitment, and shared norms/values all had favorable and significant effects on the performance of community-managed water projects in Mwanza City, Tanzania. The recommendations drawn from the findings include strengthening intimate associations and trust in community environment and improving project leaders’ interactions with members of the community in informal links and promoting social trust for improved water projects outcomes.