Intense rainfall three weeks ago caused a big section of the wall at Toddbrook reservoir in Whaley Bridge in Derbyshire to collapse.
More than 1,000 residents had to flee their homes in the centre of the town after the emergency services declared a “major incident” telling people they might die if they stayed in the path of a potentially catastrophic flood.
An emergency pumping operation eventually took the pressure off the damaged wall and saved the town, with most residents allowed to return to their homes and businesses almost a week later.
Now engineers are trying to work out the plan to repair or rebuild the wall.
Rob Powitt, managing the project for the Canal & River Trust who operate the site, told Sky News: “We still don’t know why it failed in the first place.”
He explained that the assessments currently underway will help decide how much of the wall needs to be rebuilt.
“Until we get that design on a piece of paper on a desk we don’t know where the money is going to sit and potentially whether we are going to have to back to Government for a little bit of support.
“It could be millions, it could be tens of millions potentially it could be hundreds of millions depending on the repair solution we get from the engineers,” he added.
Mr Powitt said it could be anywhere between one and three years before the project is completed.
The town of Whaley Bridge is now thriving again and businesses say they’ve actually seen an increase in visitor numbers following the attention on the town that sits in the picturesque High Peak of Derbyshire.
The playground beneath the dam wall is now open again and Leigh Turnock, who runs one of the nursery schools in the town, told Sky News many people want a total rebuild.
She said: “Well they need to start again with it really don’t they?
“It’s a very old dam it’s not recent [the construction] and I don’t think it is worth risking it happening again.”
The water level in the reservoir now sits at about 5% of the total capacity which means the town is safe.
Pumps remain on site in case further heavy rainfall threatens to bring the water level back up the wall.
An estimated 30,000 fish are still in the remaining water. Experts have decided it is too warm to move them so it’ll be the autumn before they are transferred to another reservoir in the West Midlands.