Deriving discharge strategies to reduce CSO in urban drainage systems

This paper discusses the design of discharge strategies for urban drainage operation. The design procedure applies a tuneable strategy which can be adjusted to a specific situation by adjusting a few parameters which reflect the discharge priority of the various districts of the system. The actual design procedure, a procedure of simulation and analysis of the system performance, is explained in a case study. Apart form the method, the case study shows that a near optimal performance (maximum reduction of overflow volume) can be realised by applying an “event” average strategy (one strategy for all type of inflow events). Furthermore, the case study shows that the major part of the total overflow volume is caused by very heavy storm events.