Flooding will not stop until city can tame its 3 rivers Severe deluge due to development over the years, claims expert
ALEADING academic says Birmingham only has itself to blame for this week’s devastating flood because of the way in which it has been developed around its three rivers, the Rea, Cole and Tame.
And unless water is contained at source on the rivers’ floodplains, he argues, the deluges will continue for years to come.
Homes were soaked with sewage and sodden furniture left lining the streets in large parts of the city after the flooding on Sunday.
Extreme storms caused chaos across parts of Harborne, Selly Oak, Kings Heath and Stirchley and many other parts of the Midlands when a month’s rain fell in an hour.
Dr Chris Bradley, senior lecturer in Geography and Environmental Science at University of Birmingham, lives near the Pershore Road, in Selly Park, an area repeatedly flooded over the years.
On Sunday he witnessed at first hand the devastation flood water can bring.
“This was the third flood in the area in the past decade,” he said, referring to previous events in 2008 and 2016. But the only previously documented flood of this severity was in the 1920s when people were pictured in a boat on Sir Johns Road.
“A number of factors contribute to the recent spate of floods in this area, including the construction of the Selly Oak bypass further upstream which has increased the rate of water movement through the catchment downstream.” The city is also on a plateau which can force air upwards, a major factor in the tornado of 2006 which tore through Moseley and Balsall Heath, he said. Factor in areas of clay and a high water table and localised flooding can occur in built-up areas during periods of sustained heavy rain. Dr Bradley said another contributing factor may be recent developments on the floodplain which will have reduced the potential for flood-water storage. Dr Bradley said: “The message we have to get across is flooding downstream, hold water at source.
“Significant volumes of water also pass through the sewerage system which has a limited capacity: at one point on Sunday, the water was lifting the manhole covers out of the road.” that you to stop have to
Dr Bradley said the cause of the most recent flood in the Selly Park area was similar to the one in 2016.
“On both occasions flood waters from the Bourn Brook overtopped the bank and flowed onto the Pershore Road.
“It then passed along Sir Johns Road, and Fourth and Third Avenues towards the River Rea,” he explained.
“The channel of the Bourn Brook, as it passes under the Pershore Road and through the Nature Centre, doesn’t have enough capacity to cope.
“Considerable volumes of water overspilled onto the road going to Third Avenue and Sir Johns Road.”
Dr Bradley added: “Technically, my understanding is that the Bourn Brook is defined as a ‘main stem’ river for management purposes.
“The significance is that the Environment Agency is then responsible for management rather than the council’s drainage engineering department.
“On Sunday, there was some sewer flooding which raised the manhole covers.
“We will have to look at the weather radar to see the spatial distribution of the rain.
“But it was very localised with an incredible concentration in one hour and no rain (upstream of the River Rea) in Longbridge.
“The gauges in Selly Park by Dogpool Lane and at Calthorpe Park suggest the river water was the highest that has been recorded but further upstream, in Longbridge, the river barely responded.”
Birmingham City Council said drainage system could not blamed for the flooding.
A Birmingham City Council spokesman added: “All grates and street drains are checked periodically for obstructions, with additional checks and cleaning undertaken in areas deemed be at high risk of flooding whenever a weather warning is issued.
“This was an extreme weather event, with some parts of the city seeing a month’s rainfall in just one hour, and the sheer volume of water entering the drains in such a short space of time has led to flash flooding in certain areas.
“However, we are satisfied that there were no issues with drain blockages and this is demonstrated by the fact the flood water in these areas drained away soon after the rain ended.” its be
To stop flooding downstream, you have to hold water at source. Dr Chris Bradley
> A Team Rubicon volunteer from Cornwall helps clear a house in St John’s Road, Selly Park, after the devastating floods on Sunday
> Water lifted a manhole cover in Pershore Road, in Selly Park, near the Bourn Brook
> Dr Chris Bradley