DAM AND BLAST
UNOFFICIAL REPORT INTO WHALEY BRIDGE RESERVOIR DRAMA SLAMS WORK CARRIED OUT IN 1970S - AS TOWN WAITS FOR OFFICIAL VERDICT ON THE CAUSES
FIVE months ago, only the efforts of the emergency services saved Whaley Bridge from disaster.
The ailing dam towering over the beautiful Peak District town and holding back 1.2m tons of water in Toddbrook Reservoir had failed amid a deluge of rainfall and some of the concrete slabs of the auxiliary spillway had been forced upwards and had been snapped apart.
There were real fears the dam could break apart completely and inundate Whaley Bridge with a torrent of unleashed floodwater.
It prompted the immediate evacuation of more than a thousand residents and dramatic dam repairs involving firefighters, police, soldiers, engineers, volunteers and an RAF Chinook helicopter which spent a week flying in 530 tonnes of aggregate which was dropped into a gaping hole in the dam wall while industrial pumps were brought in to drain more than a billion litres of water from the reservoir.
Until the emergency was officially declared over a week later and people were allowed back into their homes, it seemed like the attention of the world was focused on Whaley Bridge. But, almost five months on, how is the town coping? And what went wrong with the dam?
The answer to the first question is ‘very well, thank you,’ thanks to the resilience of the residents, newcomers who have bought homes there despite the events of August and an unlikely boom in ‘disaster tourism.’
Resident and shop worker Sol Campbell, 22, was among several people who told the M.E.N. they had seen ‘coaches of tourists.’ “We definitely noticed a rise of people coming in and spending money,” he said.
The second question is a bit more tricky. But what has become clear is that the original dam, built in 1830, didn’t fail at all. The problem was a concrete wall and the auxiliary spillway which were added in 1971.
Two investigations are underway and it is believed they will focus on the 1971 additions and how water managed to seep into the structure and slowly erode it.
There is a small but quite vocal band of local folk who blame the Canal and River Trust. Before its partial collapse, the dam was inspected twice in the previous 12 months and yet no structural problems were found, even though footage from 2016 showed a tree growing through the concrete slipway and residents reported that part of the auxiliary slipway always seemed to be damp even in dry weather.
Following a number of requests made under the Freedom of Information Act, the Trust released several inspection reports but large sections were redacted.
Analysis of blank inspection reports showed that sections covering ‘seepage or leakage,’ ‘settlement or movement,’ ‘scour or erosion’ and ‘serviceability of valves’ were censored. The Trust cited ‘national security’ concerns for it’s refusal to reveal the full inspection reports. Official reports into the emergency, one commissioned by the Trust and one by the government, are due to be published in the New Year.
But another report, by local retired engineer Graham Aldred, blamed the collapse on a decision by British Waterways to build a concrete overflow structure on top of the dam and an auxiliary spillway in 1971.
This addition of the 200ft long structure, along a portion of the dam wall, was ‘flawed in principle and dangerous in practice’ because it was installed on top of the dam’s clay core and risked seepage.
The new structure was added because major flooding events in the late 1960s had damaged the original spillway which runs along the north side of the reservoir.
The maintenance and inspection regime, which had not uncovered structural problems, are also criticised in the unofficial report.
Once the official reports into what went wrong are published, work can begin on designing and building what will in effect be a new dam, costing in the region of £10m. It is hoped work will start in April 2021.
One of the town’s most famous residents, former Conservative MP Edwina Currie, urges a ‘radical rethink’ of how our reservoirs, and countryside, are managed, saying more trees should be planted to prevent silting. She said: “We feel safe, that’s not the problem. We just feel like we’re dealing with people (stuck) in the 19th century. There’s too ready a trust in how things have been.”