Moray Council is set to meet today to consider four options to remediate slope stability issues that cut one Scottish village off from its harbour last year.
Source: Can Geotechnical
Heavy rainfall on 13 September 2017 caused at least 22 separate landslips and mud flows around Harbour Road, Patrol Road and Cliff Terrace area in Portknockie.
Options open to the council that were developed by Can Geotechnical range from doing nothing through to carrying out extensive repairs that are estimated to cost £2M (see below for details of the options).
Can undertook site work in the village in late November to assess the potential for soil nailing and netting to reduce the risk of further slope failures and has recommended the use of a soil nailed solution to medium and high risk areas at a cost of £1.74M.
Can has urged the council to progress with works swiftly to avoid further deterioration of the failed slopes.
Rob Barsby who is chairman of Portknockie’s flood action group, which was formed following the landslips, explained waiting for a plan to fix the damage had been “frustrating”.
He said: “The roadways have been left completely undermined all this time. Obviously, the longer it’s left like that the bigger the risk of something catastrophic happening.
“It’s been very frustrating waiting for something to happen, things have been moving slowly.
“I realise it’s not like Gardenstown where people can’t get to their homes but there’s no telling what another rainfall would do.
“It’s a complex situation though so the most important thing is we get the right solution.”
In a report, Debbie Halliday, the council’s acting consultancy manager, warned approving the do nothing option would risk “significant reputational damage” in addition to £800,000 in costs.
Halliday said that in some areas the landslips are threatening the stability of property and infrastructure and she urged the council to “consider repairing the high risk areas at the earliest opportunity to avoid further damage”.
- Do nothing – this would require road closures and compulsory purchase of affected property. This solution has an estimated cost of £800,000.
- Repair high risk areas only – this option would target four high risk areas using soil nails and drainage improvements at a cost of £890,000
- Repair medium and high risk areas only – in addition to the treatment above, this option would treat an further four areas using similar techniques to the high risk area only approach. The costs associated with this solution are £1.74M.
- Repair all areas – this option would additionally treat another three sites by trimming slopes and installing geocomposite to mitigate the effects of surface erosion. The total cost of this work is estimated at just over £2M.