A key feature of the flooding in Vale Avenue is that it came in two waves. A first and lower peak caused by surface water flooding and second event caused by overflow from Letcombe Brook. At the peak of the second event several houses were flooded and others only narrowly missed the same fate. The diagram below summarises this. It shows schematically how the flood levels rose during the rain, fell as the rain eased off and then rose again after the Sun had come out.
The double peak in the flood level and the timing of the second peak clearly show that the second damaging peak was due to overflow from Letcombe Brook. It put paid to the
myth that Vale Avenue flooding was solely due to local surface water flooding.
The second peak also supports the idea that the peak flooding in Grove was associated
with a surge of water coming down Letcombe Brook.