The study area for the Environmental Flow requirements is the Orange River Catchment which traverses four countries, i.e. South Africa, Lesotho, Botswana and Namibia. The focus of thernResource Unit delineation is only for the rivers in which EFR sites will be selected, i.e. the Caledon River, Orange River downstream of Gariep Dam, the Kraai River and the Molopo River from its source to the Ramabatlama confluence.