Infrastructure owners worldwide must extend the life of ageing assets while keeping them safe, reliable and operational. Rehabilitation is harder to manage than new construction because it starts with incomplete knowledge, hidden deterioration, continuing public-service obligations, and many organizations whose decisions affect delivery. Therefore, the central challenge is not engineering design alone, but the disciplined management of uncertainty throughout the asset lifecycle. India’s Dam Rehabilitation and Improvement Project (DRIP) is one of the world’s largest coordinated rehabilitation programs. DRIP-I rehabilitated over 200 large dams, while DRIP Phase II and III are expanding support to more than 700 large dams across nineteen States and three Central Agencies. The program combines physical rehabilitation with governance reform, investigations, independent technical reviews, procurement and contract management, construction quality assurance, digital asset management, environmental and social safeguards, financial control, emergency preparedness, and institutional capacity building. This study examined DRIP as a project-management system. It explains how preparedness was used to reduce uncertainty before procurement, how national consistency was balanced with decentralized ownership, how evidence guided scope changes, how construction was integrated with reservoir operation, and how digital systems, O&M manuals, Emergency Action Plans, and permanent knowledge institutions were integrated to sustain benefits after construction. This study proposes an integrated ten-function framework that can also guide the rehabilitation of other ageing public assets.