Protecting Ecological Integrity in Transboundary Watercourses: An Integrational Approach towards Implementing Environmental Flows

The thesis explores the obligation in international law to protect the ecological integrity of transboundary watercourses. The thesis specifically examines the obligation to protect environmental flows, which essentially means to protect a certain water flow for the benefit of freshwater ecosystems and the ecosystem services they supply. The obligation to protect the integrity of transboundary watercourses' ecosystems is understood to apply within the context of the principle of equitable and reasonable use, meaning that the protection of ecosystem in most cases will be subject to a reconciliation process where uses of a watercourse are made subject to trade-offs between competing needs and interests. The scientifically defined requirements of water flow (i.e. the magnitude, timing, rate of change, frequency and duration of water flows) and the application of an equitable and reasonable use are in the thesis analysed within th context of five transboundary case studies. A novel analytical framework, combining relevant law and science aspects is developed to assist in these analyses.
The thesis contributes to a better understanding of the law-science interface and to a clearer perspective on the normative scope of the obligation to protect the integrity of transboundary watercourse ecosystems. The thesis furthermore provides a novel analysis of the legal capacity required to implement this obligation, as well as an analysis of the legal capacity of regulatory approaches used for implementing environmental flows.