The Nile and its main tributaries flow through a large variety of ecosystems, each of great relevance for biodiversity conservation und human livelihoods, and providing important regional and local ecosystem services. The continued provision of these ecosystem services is heavily dependent on a minimum water flow, or environmental flows.

The NBI supports its member states in sustaining and enhancing Environmental Flows (or E-Flows) in the Nile Basin in a cooperative manner. Environmental Flows describe the quantity, quality and timing of water flows required to sustain freshwater and related ecosystems, as well as the human livelihoods and wellbeing that depend on these ecosystems. Environmental Flows are important for the maintenance of biodiversity and ecosystem services provided by the river, including provisioning (e.g. water as a basic human right, livelihood through fisheries), regulating (e.g. water quality and quantity), cultural and supporting services. To maintain these services, water needs to be allocated to sustain the functioning of the river ecosystem and avoid flow alterations where negative effects are foreseen.