Taxpayers face repair bill over collapse of port harbour wall

The problems started in February 2009 when a section of steel sheet pile wall in the lower harbour between the swing bridge and the lifeboat station collapsed.

An independent report claimed the collapse was a result of essential dredging that had lowered the harbour bed so much the wall could no longer support the load behind it.

Yorkshire Water, which owns the structure, is negotiating with the council for a contribution towards finding a solution. It appears to have collapsed following repeated dredging of the main harbour channel and the dredging of the nearby yacht club pontoon area. This lowered the level of the harbour bed, so material nearer the sides had slumped away to compensate and the wall itself was no longer able to support the weight of the material behind it.

Yorkshire Water has received expert advice that “the council’s dredging activity to maintain a safe channel in the harbour is a factor”.

Scarborough Council’s head of legal and support services Ian Anderson said:

“A sheet pile structure was constructed in 1963 to 1964 along the harbour bank during a major redevelopment of the sewerage system in Whitby by Whitby Urban District Council, which was then the responsible authority.

“The structure consisted of 400 millimetre-wide steel sheet and box pile sections which are only 4.5 to 5.5 metres in length extending from the slipway below the east car park to the RNLI Whitby lifeboat station.

“At these lengths, the purpose was to protect the sewerage system, not to perform a structural role as the harbour bank.

“In 1979 Whitby Marina was constructed involving dredging works to deepen the navigation channel.

“Maintenance dredging has been carried out thereafter every 18 to 24 months to maintain the harbour bed.

“The expert commissioned by Yorkshire Water has advised that in his opinion in the 30 years since 1979, there has been a gradual migration of material from the upper, marginal areas of the harbour bed, from both slumping of the side slopes of the dredged channel and natural hydraulic scouring.

“In the opinion of the expert employed by Yorkshire Water this gradual migration of material caused harbour bed levels immediately in front of the piles to become too low to support the load behind the piles, leading to the localised collapse.

“The 4.5- to 5.5-metre piles were subsequently replaced by 10.5 metre piles.

“As a result of this work, some damage to properties in the vicinity is said to have arisen. Yorkshire Water and Scarborough Borough Council are working together with property owners toward an amicable resolution.”

He adds that Yorkshire Water has taken “the pragmatic view, that it is important to resolve the problems by working together with the borough council in the interests of the community.”

At least £50,000 has been put aside to deal with the problem but Mr Anderson says “it is now clear that a sum in excess of this amount is likely to be required to achieve resolution”.

Inquiries by the Yorkshire Post have revealed that it will be a six-figure sum, but not significantly more.

A Yorkshire Water spokesman said: “The independent report ascertains that the instability of the pilings was brought about by the progressive lowering of the harbour bed during the marina development.

“Alongside Scarborough Borough Council, we are committed to working together with property owners in order to ensure we reach an amicable resolution with a report detailing various options going before the council’s Cabinet later this month at Scarborough Town Hall.”