Flood-hit Alyth was hammered by a month’s worth of rainfall in just six hours, a new study into this summer’s catastrophe has revealed.
Environmentalists have blamed an “exceptional intensity” of torrential rain for devastating flash flooding in July.
The Perthshire town sufferedmillions of pounds worth of damage when fallen trees and logs were washed downstream, clogging up bridges and swamping dozens of homes.
The Scottish Flood Forum and Perth and Kinross Council were yesterday finalising an extensive investigation aimed at getting to the root of the problem.
And initial findings have revealed that between 50mm and 60mm of rain about four weeks’ worth fell over six hours on the morning of Friday July 17.
The full findings of the investigation will be revealed to local residents and businesses in the coming weeks.
Questionnaires were sent out to households following the flooding. Investigators are also asking for anyone with photo and video evidence, as well as eyewitness accounts, to get in touch.
It is known that at least 47 private and council-owned buildings were affected but council officers believe the actual number could be even higher.
A new flood bulletin issued to affected residents and businesses says: “The initial findings indicate that the exceptional intensity of rainfall over the Alyth area immediately prior to the event (50mm to 60mm over six hours) is the main cause of flooding.
“A large amount of wood debris transported by the river and blocking structures has also contributed to the severity of the flood event.”
The data has been gathered by the Scottish Environment Protection Agency using evidence of “flood trash marks” indicating the highest waterlevels at locations throughout the town.
Statistics from local rainfall gauges have also been used to estimate the size of the flood.
A council spokeswoman yesterday said: “The joint report into the recent flooding in Alyth is currently being prepared. Arrangements for sharing the report with the community and other key stakeholders will be confirmed in due course.”
Work to remove fallen trees and logs between the town centre and Den of Alyth has been completed. Following the flood residents went out night after night with diggers and machinery to clear the water of wood.
Contractors are also removing large boulders and sediment brought down by the flooding. Work has been carried out to fill in river beds and banks which were damaged.
Meanwhile the council is continuing to investigate land ownership to establish who is responsible for wood debris entering the Alyth Burn.
Local MP Pete Wishart hasreopened the town’s Price Kracker store, which was extensively damaged in the flood.
He said: “It is reassuring to seebusinesses reopening and life returning to normal.”