This Advisory Leaflet introduces the basic aspects of real time control to potential users and presents a sound level of knowledge to those planners, operators and administrations involved in the development of real time control systems. The Advisory Leaflet aims to achieve the use of real time control as a potential alternative on a regular basis in future planning of drainage schemes. This includes simple local control systems as well as complex structured interconnected control systems. The necessary steps along the planning process are shown and explained. The Advisory Leaflet discusses significant questions in the context of real time control concerning sewage discharge, stormwater treatment in separate sewers (overflow of contaminated fraction into combined sewers) and sewage treatment in combined sewage networks.