ABSTRACT
The fundamental issue relating to stormwater management has already been referred to a number of times in this book. Fig. 1.3 illustrates the combined effect of covering areas with impervious surfaces like roofs and roads, and carrying rainwater runoff away in a piped system. The result is an increase in the risk of flooding and pollution of the natural watercourse to which the runoff is discharged. In Section 2.1 we introduced a way of reversing this trend: to drain developed areas in a more natural way, using the infiltration and storage capacities of semi-natural devices such as infiltration trenches, swales and ponds – SUDS as they are known collectively in the UK (standing for Sustainable Urban Drainage Systems, or SUstainable Drainage Systems). Earlier chapters, especially Chapter 11, have dealt with piped systems for stormwater, so in this chapter we consider the alternatives to pipes.
