The Great Flood, New Year's Day 2025
The Great Flood, New Year's Day 2025
Background
The River Mersey in south Manchester runs through numerous communities from the confluence of the Rivers Goyt and Tame at Stockport, through Didsbury and Sale. The Environment Agency operate and maintain a flood risk management scheme which comprises two flood storage reservoirs (at Sale and Didsbury), flood embankments and walls, and other flood risk management assets such as debris screens and penstocks. The scheme was originally constructed in the 1960s and ‘70s with upgrade works completed in the Northenden area in the early 2000s. By operating the flood storage basins, it is hoped that the level of the river will fall and thousands of properties further downstream will be saved from flooding. However, there are properties in these flood basins and they rely on receiving a warning from the EA about when the sluice gates will be opened – especially when it is noted that they are usually uninsured and need time to move things in the event of a flood. The relatively slow pace at which the flood storage basin fills up usually gives the time required to move machinery and equipment etc to safety and higher ground.
What happened?
Heavy and persistent rainfall throughout the afternoon and evening of 31st December 2024 and into the early hours of the next day resulted in the River Mersey reaching record levels in the south Manchester area; a month’s rainfall fell in 18 hours. Within just a matter of hours the river was overflowing at various points and its right embankment eventually collapsed and burst approximately 260 yards upstream of Simon’s Bridge – on the curve of the river adjacent to nearby Stenner Lane and Simon Field. This created a gap of some 43 yards through which the swollen river surged carrying large quantities of debris, soil and logs and moving anything in its path that was moveable. This was arguably the main cause of the devastation left in its wake in Simon Field, Bradley Fold Allotments, Withington golf course and beyond Palatine Road. It is understood that the EA opened the sluice gates at Millgate Fields at around 3.00am on New Year’s Day as the ‘trigger’ level was reached, but without the agreed final warning being given. At around 4.15am they were opened to 50% and fully opened at about 5.00am. Subsequent to this operation, the river embankment was breached at around 6.00am. It is understood the sluice gates were not fully closed until 16.45pm on 1st January.
This horrendous flood was caused by the combination of a number of factors – the sheer volume of rainfall in the catchment area and the speed at which it drained into the river; the record high level of the river and the speed and force at which it was flowing; the collapse and breaching of the right embankment approximately 260 yards upstream of Simon’s Bridge; the fact that the design standard for some of the flood defences was exceeded, leading to overtipping; and the opening of the sluice gates at Millgate Fields. A further relevant point is the fact that the banks may not have been as robust and holding as they might have been as they were made and supported by spoil of brick and soil rubble from past slum clearance sites.
The consequential scale of the flood damage was unparalleled in the local area. Didsbury Sports Ground clubhouse was flooded and damaged; fences were destroyed; bins, chairs, tables and other outdoor furniture were swept along and ended up in the allotments or beyond.
As for the allotments, the scene was almost apocalyptic. It was almost as if it had been hit by a mini tsunami. It was a mangled mess with debris everywhere. The power of the floodwater and its load can be seen in the fact that the large rectangular steel container cabin, sited just inside the entrance gates, was lifted off its concrete support blocks and swept along for approximately 200 yards before coming to a halt near the boundary with Withington golf course. Other sheds, bins, barrels, fencing, buckets, containers, equipment, and implements were strewn across the golf course together with logs, branches and other debris some of which ended high up on trees and bushes. Some sheds were deposited on the course near Palatine Road. Mud and silt were widespread.
Withington golf course was flooded to a depth never seen before. Locker rooms, office, professional’s shop, and ground floor of the flat were all under water. Palatine Road and properties along its route were flooded. The road was closed and residents had to be evacuated; cars were submerged and power cut off. Further downstream, the river eventually breached its left bank twice and flooded Northenden golf course and its clubhouse. Another breach occurred to the right bank when floodwater from the area behind the Britannia Hotel forced its way back into the river.
This flood – and others in south Manchester and Stockport – became stories of national interest as TV and other media outlets reported the unfolding drama and human misfortune. Local residents strolled down to Ford Lane to view the watery scene and to take photographs with their mobile phones. For those who had not witnessed a flood before, there was an element of shock and awe at what they were seeing. For those accustomed to local floods, nobody had ever seen anything as devastating as this one. Lots of photos were taken, including some by aerial drones.
All of this – and more – was what greeted early risers on Wednesday 1st January, 2025.
Second flood
Within a day or so the level of the river had fallen and the floodwater had receded a little. However, following more rainfall and melting snow the river level rose again and a second flood occurred on about Monday 6th January as a consequence of the breach in the river bank near Simon Field. This second flood did not cause too much damage but helped to delay the clearing up operation.
Aftermath
Because its clubhouse was built in the floor storage basin, Didsbury Sports Ground were not insured and almost immediately launched a crowd-fund appeal to raise money to help offset the cost of cleaning up and replacing equipment etc. The EA began pumping water back into the river from Simon Field until the level became too shallow to continue. Members of the club volunteered to clean up and do whatever they could. Large skips were brought in and filled with damaged furniture etc.
Within a week or so it was announced that the breach in the bank near Stenner Lane would be temporarily plugged. The idea, in the short term, was for the gap to be filled with one-ton rock bags, currently stored in the car park of Withington Golf Club where a special fenced-off compound had been formed. A helicopter would be used to lift the bags into place. Although this operation would not completely fill the gap, it was hoped that it would suffice until the EA had the time and resources to return and do a more permanent job. It must be remembered that the EA had many emergencies to deal with at this time – flooding, pumping, breaches, bank erosion, debris clearance etc.
Global warming?
Whether global warming has had a part to play in the frequency of these floods is not part of this exercise. However, when the concept of the flood storage basins was developed in the early 1970s it was said that, based on statistics for the previous 50 years, a flood could be expected every 16 or 17 years. Clearly this has not been the case.
Mother Nature
It is perfectly natural for a river to flood – that’s what they do from time to time; that’s why they have flood plains. With the best will in the world, the EA can only do so much; it cannot prevent flooding. Its staff manage the river as best they can with the latest equipment and monitoring devices and those who build on flood plains must question their wisdom in doing so.