'Sobering reading': What new Ripon Leisure Centre report says about underground void discovery

In the report published by Stantec, the engineering firm details how the void was found during works on the centre's new multi-million pound swimming pool and why further investigations and groundworks are now required.

It said initial studies suggest there has been a "significant deterioration" of the ground beneath the older half of the centre which was built in 1995 and like much of Ripon sits on gypsum deposits.

The report begins by looking at construction records which reveal several ground piles had failed during the build almost three decades ago.

Stantec said the piles were not driven deep enough into the ground and that it remains unclear why this happened as "many critical records" are missing.

Replacement piles were added during the build, the report said, but it is believed these were driven into partially-filled holes.

Fast-forward more than 20 years after construction was completed and a sinkhole opened up outside the centre in 2018.

A year later, the refurbishment plans and new pool were approved by Harrogate Borough Council despite some councillors raising "deep concerns” over ground stability.

These works began shortly after and Stantec's report said it was in September 2020 when the void was found by construction crews.

This was investigated and all areas beneath the older building will now be examined in the New Year.

The report said the void is having a "limited impact" on the building but "will continue to degrade over time" without action.

Stantec gives three options to solve ground stability issues across this half of the site: do nothing, demolition or ground strengthening.

It said the do nothing approach is "unacceptable from a public safety perspective", while demolition was not considered to be "cost-effective" by the council.

It added strengthening could include steelworks, thickened floors and grouting where mortar is pumped into the ground - the same method "successfully" used to stabilise the new swimming pool building.

However, it said strengthening alone is "unlikely to mitigate risks to acceptable levels" and that other measures would be required including long-term monitoring.

The report added any ground collapse before or after these works was not likely to be "catastrophic" but would be gradual and seen through cracks in the building.

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At Wednesday's meeting, council leader Richard Cooper said the findings made for "sobering reading" before he and other cabinet members approved the next stage of investigations.

Other council officials stressed the centre is "safe to use" and that the new pool, due to open on 8 December, will not be affected.

Councillor Stanley Lumley, cabinet member for culture, tourism and sport, said: "It is very important to distinguish that there are two separate issues and projects here.

"The ambition of this council was to build the best possible health and well-being facility for Ripon. The best way to do that was to combine the old leisure centre with the new pool adjacent to it.

"Only during the construction of the new pool was it identified that there was a potential problem with the existing building.

"We have got professional engineers, designers and consultants on the site, and we have to take advice from them.

"That’s why we pay them, that's why we employ them - and we should surely act on that advice."

During the strengthening works, the older half of the centre is likely to close for around six months when the council said it would look to provide gym facilities at a different venue in Ripon.

The closures will mean the centre - which was due to be refurbished and open its new pool earlier this year - will not fully reopen until mid-2022.

By Jacob Webster, Local Democracy Reporter