Concepts of Urban Drainage and Flood Protection

The significance of the introduction of modern computer technology to design, analysis, operation and control of sewer systems during rain is analyzed. With new tools come new basic concepts and new engineering criteria for performance. The most significant developments are: the capability to calculate surcharging and flooding, rather than just relating to pipe capacity performance criteria; the capability of calculating long series of rain record in order to derive proper statistics on the pollutional load on the environment; and finally the capability of dynamically controlling the system in real time in order to decrease the pollutional load by optimization of the usage of storage at rains smaller than the design rain, without increasing the risk of floods.