ABSTRACT
It may be appropriate here to recap some elements of Chapter 1. Urban drainage systems handle two types of unwanted water: wastewater and stormwater. An important stage in the history of urban drainage was the connection of wastewater to ditches and natural streams whose original function had been to carry stormwater. The relationship between the conveyance of wastewater and stormwater has remained a complex one; indeed, there are very few systems in which it is simple or ideal.
