Dr. Jackie King was named the 2019 Stockholm Water Prize Laureate for her game-changing contributions to global river management. She has advanced the scientific understanding of water flows, giving decision-makers methods and tools to assess the full range of costs and benefits when managing or developing river systems. Dr King led the early development of the methods as a researcher at the University of Cape Town, funded by South Africa’s Water Research Commission. Later, she and colleagues Dr. Cate Brown and Dr. Alison Joubert created ecosystem models to demonstrate the ecological and social implications of damming and de-watering rivers. This has enabled objective assessment of the costs of water-resource developments that could emerge linked to benefits such as hydropower and irrigated crops.