DRAINAGE systems were overwhelmed by the sheer scale of the weather during the floods last June, a report suggests.
The study, commissioned by West Sussex County Council, investigated the reasons behind the floods that swamped parts of West Sussex, including Bognor, Chichester and Southbourne.
The report said the rainfall was a once-in-200-years event, with five times the average rainfall for the month.
The report states: ‘Modern surface water systems are generally designed to frequencies of 25 to 100 years.
‘Consequently, not unexpectedly, many systems were overwhelmed causing flooding in vulnerable low areas.’
It goes on to say that the events of June 10 and 12 highlighted weaknesses in both the management of drainage and its infrastructure.
The report added: ‘Some of these are in the process of being resolved, others will require further detailed work or investigation.’
An estimated 780 properties were flooded.