Abstract1. This paper discusses the characteristics of scientific information used in river conservation and management.2. Information should be appropriately focussed, achieving a balance between the ideal and the achievable, recognizing the functioning of riverbasinsand not merely riverchannels.3. Technical data need to be presented in a way that is readily understood by decision‐makers — simply, but not simplistically. This is discussed using examples such as river corridor mapping and the application of numerical indices of water quality and conservation value.4. Ideally, river management policy and practice requires a scientific input that is both unequivocal and authoritative. Frequently, however, disagreement over its interpretation delays information transfer.5. The results of applied studies in freshwater science are not always as accessible as they should be to river managers. Once acquired there must be a genuine willingness by planners to incorporate the results of ecological research into project design, a process often hindered by complex bureaucratic structures. It is thus argued that operational flexibility in river management schemes is desirable, and post‐project appraisal esse