In their latest SuDS manual, CIRIA offers the following definition: ‘’Sustainable drainage systems (SuDS) are designed to maximise the opportunities and benefits we can secure from surface water management.’’

Fundamentally, SuDS mimic mother nature in urban environments where there tends to be less permeable ground for infiltration. When rain falls on impermeable surfaces like pavements and car parks, the risks of flooding and erosion are increased because water has nowhere to runoff and be drained away, so SuDS can be installed to manage rainwater where it falls.