'I've worked on the Eurotunnel, there's another flood defence solution that will save the Royal Limes'
“I’m not a crank, nobody is more interested in flooding than me.”
A leading engineer who has worked on huge projects for more than 50 years, has come up with an alternative flood defence proposal to save the Royal Lime trees in Walton-le-Dale.
Preston man John Hull, 80, has worked in construction since the age of 17, and in 1996, founded Sheet Piling UK, the country’s leading steel sheet piling contractors. He is still chairman of the company and has been involved in huge engineering works, including Eurotunnel, HS2, motorway widening and many aspects of flood defence works across the country.
Now John, who is representing himself and not the company, has submitted an alternative proposal for flood defence works in Walton le Dale, which would remove the need to cut down 18 of 21 lime trees in Victoria Road to facilitate the next phase of the Environment Agency’s multi-million-pound Preston & South Ribble Flood Risk Management Scheme which began in 2022.
The lime trees were planted on the bank of the River Ribble in 1912 to commemorate the coronation of King George V, and more than 8,000 people have signed a petition to save them.
The EA proposals - which involve installing a 16m-deep underground concrete wall (cased secant piled wall) along the footpath that would cut through the tree roots - were formally approved by South Ribble Borough Council’s planning committee on March 27. They say this work is vital to reduce flood risk for hundreds of homes and businesses in Walton-le-Dale.
The EA has said that “extensive investigations” were conducted into alternative designs that could preserve the Lime trees on Victoria Road, but were not found to be viable. They said: “This included tree root radar surveys and engineering assessments. Unfortunately, due to the density and spread of the root systems, and the proximity of the trees to the required working area, it is not feasible to retain them.- The secant piled foundations required for the new wall will cut through the roots anchoring the trees. Contractors also require sufficient space for machinery to operate safely. As a result, the trees cannot be retained.”
But Mr Hull, who remembers his grandmother from Higher Walton telling him about the history of the trees as a child, claims there is an alternative way. Instead of installing the proposed secant piled wall, he wants to shift the focus to stabilising the existing riverbank.
Key Components of John Hull’s alternative solution involve:
- Installing an Anchored Sheet Pile Wall either directly in front of or behind the existing 200-year-old masonry wall to secure the slope and prevent potential failure.
- Deploying a ‘Silent Vibration-Free’ Giken Crush Pile Press to install the sheet piles. Mr Hull claims this advanced technique causes minimal disturbance to the riverbed and completely protects the Marine Conservation Zone.
- Construction of a simple dwarf wall. He said: “With the embankment fully stabilised, the flood defence height can be raised by the required 275mm using a simple dwarf wall at the back of the footpath - matching the successful design rationale used in 2002 which has successfully protected the community for 24 years, withstanding all the highest levels on record without overtopping or seepage beneath the wall.
- Incorporation of isolated bearing piles driven into the underlaying dense sand layers at 7m depth to guarantee the long-term structural stability of the new dwarf wall - something he claims is a minor modification requiring only two to three days of work.
Mr Hull, who lives close to the bank of the River Darwen, claims the work would be more time efficient, and at an estimated cost of £1.3 million for the specialist piling, would cost a fraction of the price of the EA current proposal. He also claims it would remove the need for extensive road closures in the area.
Mr Hull said he considers the flood defence works in the area as a “routine job”, and says that he he is professionally frustrated at the EA proposal. He said: “I’m not a crank, nobody is more interested in flooding than me. I’ve spent my life doing it (flood defences) and I just don’t agree with the EA proposal, it’s irrational.”
On a personal level he said: “I have eight grandchildren and two great-grandchildren, and I want them to see the trees that were probably contributed to by my grandmother. I also want the EA to recognise the historical importance of the trees.”
The EA response
An Environment Agency spokesperson said: "We welcome the group's continued engagement with the flood scheme, and we are meeting them on August 28 to discuss their proposal. The Scheme is committed to considering it fairly and looks forward to hearing directly from the Campaign Group before commenting further.
"Any alternative proposals are considered against the same criteria and standards as the current scheme."
Why can’t they build around the trees?
In April, the EA said: “Constructing defences in front of the trees, closer to the river, was considered. However, this option would require temporary obstruction of a section of the river, which would increase flood risk. It would also make the scheme financially unviable and cause serious environmental harm to the river, which is situated within a Marine Conservation Zone.”
Furthermore, the Environment Agency is unable to move works towards the pavement and carriageway. This is due to the large number of services that run adjacent to the existing wall, including a critical fibre optic communications cable of regional importance. Surveys also found that the tree roots appear to be causing damage to the pavement and pose a risk to the services beneath it. There is also evidence that the roots have caused damage to the existing surface water drainage system on Victoria Road.