Blocked drains, poor maintenance and an amount of rainfall expected once in every 40 years culminated in homes flooding across West Norfolk.
More than 1.5 inches of rain fell during just one day last year and 36 properties were flooded as a result.
A total of 42 properties were flooded in the borough between June and November, but 86 per cent of them were damaged during the August 8 deluge.
A report published this week shows a combination of factors, including blocked drains, insufficient capacity and overgrown dykes had all resulted in a spate of flooding in an area from Stoke Ferry to Upwell and King’s Lynn to Necton.
Fire crews were called to help at a number of homes which were damaged by water.
Norfolk County Council commissioned a report which aims to identify organisations which have a role in flood management and outlines some of the reasons properties were so badly affected.
“In some locations proactive investigations and remedial work has already been undertaken by Anglian Water, Norfolk County Council Highways and a number of internal drainage boards to identify issues, clear and repair surface water systems to ensure that residents are better protected from flooding,” says the report.
But maintenance programmes operated by the key authorities should be reviewed in areas where there are issues, it adds.
Blocked drainage channels, called grips, had also not helped the situation.
“There is a need for better coordination between the relevant internal drainage boards, Norfolk County Council Highways and Anglian Water in relation to routine maintenance works on the drainage systems in the borough.”
It also suggests the authorities work together to apply for funding to mitigate flood risk associated with their areas of responsibility.
“In a number of instances lack of maintenance of open dykes had allowed excessive undergrowth.
“Some areas experienced localised extreme rainfall. These events could not reasonably be accommodated by the design standard of the local drainage systems,” says the report.
Some of the affected properties were flooded because they were below the level of an adjacent road and surface water could not dissipate quickly enough.
The report recommends more co-ordinated working between all the authorities involved, more rainfall gauges across the borough for data collection; information sharing and ensuring foul and combined drainage systems are identified.
A drop-in session was due to be held yesterday evening in Upwell for residents and authority representatives to discuss the report.