ABSTRACT
Until relatively recently, the basic philosophy and practice of drainage of urban runoff has been to solve flooding problems by transferring large quantities of stormwater downstream as quickly as possible. This has been accomplished using the basic drainage technology, described in earlier chapters, of roads and roofs draining to piped sewers. Whilst this approach was successful in eliminating local flooding problems, the increased volumes and peak flows caused downstream flooding problems together with pollution and erosion of natural receiving water bodies.
