How do drainage systems cope with heavy rain?

As flooding from Storm Dennis persists, Dr Sarah Bell (UCL Bartlett School of Energy, Environment & Resources) explains how drainage systems work, saying that slowing water’s progress into drains is more effective and efficient than attempting to enlarge existing infrastructure.

Listen: BBC Radio 4’s ‘PM’ (from 34 mins 50 secs), More: BBC Radio 2’s ‘Trevor Nelson’s Rhythm Nation’ (from 1 hour 42 secs)