Environmental flows - basics for novices

The term environmental flows has become widely used to define the hydrological regime required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend on them. A large range of frameworks and methods has been developed to assess environmental flow needs and many authors have identified subtleties in the approaches needed for different situations and required outcomes. This article summaries some basic concepts that can assist those new to environmental flows to navigate the rapidly expanding plethora of information. It briefly covers key areas of setting objectives for river ecosystems, examining pressures that constrain reaching these objectives, the level of detail needed, implementation, and how future changes affect environmental flow assessments.