Dams on transboundary watercourses are vital to ensure water security, yet no comprehensive international legal framework governs their development. This thesis addresses this gap by defining States’ rights and obligations towards other States and affected populations during dam planning, construction, and operation by analyzing relevant legal instruments and jurisprudence.

The first part examines States’ duties toward other States under international water and environmental law, focusing on procedural and substantive obligations during dam planning, construction, and operation. The second part explores States’ human rights obligations toward individuals and communities affected by dams, including the human right to water, and extraterritorially, advocating for a human rights-based approach to safeguard vulnerable populations. By bridging water, environmental, human rights, and humanitarian law, the thesis proposes a comprehensive legal framework for sustainable and cooperative dam development that balances sovereignty, environmental protection, and the rights of affected populations and ecosystems.