Six options for the future management of Undercliff Drive, St Lawrence are to be discussed by the Isle of Wight Council’s Executive when it meets next month (7th July).
A report before the Executive is recommending that the Council and Island Roads develop more detailed costings of the various repair options before a preferred scheme is agreed.
The six options have been developed following the compilation of three reports by Island Roads about sections of Undercliff Drive which were affected by ground movement earlier this year. Land movement at two main locations left nine properties landlocked and inaccessible by vehicle.
The land movement followed rainfall levels during the winter of 2013/2014 which were 25% higher than any previous figures for the location.
The options being considered include re-establishing access to the nine properties or possibly reopening Undercliff Drive to through traffic. The options are as follows (provisional estimates in brackets):
- Option 1 – re-establish pedestrian access only (£250,000 to £500,000).
- Option 2 – repair and reopen the road with access from one direction only (£1 million to £2.5 million).
- Option 3 – repair and reopen through road from Ventnor to Niton (£6 million to £20 million).
- Option 4 – establish a new access road to properties along the base of the cliff (£200,000 to £500,000).
- Option 5 – establish a temporary low cost road from the west (initially less than £100,000).
- Option 6 – permanent vehicular closure of the affected part of Undercliff Drive, pedestrian access limited to residents.
The three reports submitted by Island Roads were published at the end of May and outlined factors including what actions were taken in the lead up to and following the geological failure; what actions Island Roads proposes to rectify, manage and/or mitigate the geological failure; and a financial estimate of costs of proposals.
Under the Island’s highways PFI contract, should a section of the highway fail for geological or geotechnical reasons, Island Roads is required to provide the council with a technical report, known as a failure report.
The report to the 7 July meeting of the Executive follows consideration by council officers of the three failure reports – which were posted on the council’s website so residents and affected parties could study the findings of Island Roads and its specialist geotechnical consultants. The reports can be found at: https://www.iwight.com/Residents/Transport-Parking-and-Streets/Highways-PFI
Island Roads is continuing to monitor groundwater levels as well as surface and sub-surface groundwater movement at the location – and the monitoring shows that while ground movement has slowed, it has not stopped. One of the affected properties has been declared unsafe by the council’s building control section, which continues to monitor the remaining properties. Two of the properties are still occupied.
There has also been ground movement identified at several places away from the two major areas of ‘failure’.
The council and Island Roads have held meetings with affected residents to keep them informed of progress with the reports and the options under consideration.
The report to the 7th July meeting of the Executive states:
“The initial cost estimates set out by Island Roads in their failure reports indicate that some form of improved access is probably affordable.
“However, without more detailed information regarding the construction costs it is not possible to determine which of the potential schemes is preferred.
“It is therefore appropriate that officers investigate which of the possible options suggested by Island Roads can be delivered at an affordable cost, whilst considering the wider threats to Undercliff Drive from ongoing instability problems.”
Councillor Jon Gilbey, Executive member for resources and highways PFI, said:
“The three reports from Island Roads have been closely studied and it is now being recommended that the six options arising from these reports are fully and properly costed before we propose a preferred way ahead.
“The welfare and concerns of the affected residents remain paramount, and in the mean time we are keeping them fully aware of progress – and are reassuring them that we are doing all we can to reach a decision on the road’s future as soon as possible.”
