This chapter examines Japan’s development cooperation by taking a closer look at three water-related projects. It opens by reflecting on water as a life-sustaining and potentially destructive force, framing the management of water as a political challenge. The chapter situates water governance beyond the dichotomy of state control and market mechanism, emphasising the importance of community-based management of the commons. Three case studies follow. First, the Brantas River Basin Project in Indonesia that originated in Japan’s post-war reparations evolved over decades into a model of local autonomy and technical mastery, symbolised by the enduring ‘Brantas Spirit.’ Second, the Salmon Stocking and Aquaculture Project in Chile became a successful incubator of Chile’s modern aquaculture industry, despite later constraints such as the 2009 ‘Sanitary Crisis’. Finally, the Kilimanjaro Rice Irrigation Project in Tanzania achieved productivity gains but later faced serious water conflicts, highlighting the need for cooperative management among farmers. Across these cases, the chapter stresses the importance of long-term human resources development over short-term metrics. The trust-based engagement of Japanese experts and their local counterparts enabled the projects to progress towards independence and autonomy, demonstrating how technology transfer, local adaptation, and shared stewardship can sustain both human and natural resources.