Silt removed from Peel Marina will be used to help restore uplands left damaged following 19th century mining activity.
Details of the innovative solution are being released today following the submission of a planning application to allow dredged material to be temporarily stored and drained in an engineered and lined pool on the outskirts of the town.
If dredging does not take place, accumulation of the silt threatens the closure of a number of berths within the marina, which was last dredged in 2015.
The project to remove 44,000 tonnes of silt is due to begin next year and will take place in distinct stages.
The first stage will involve a proportion of the material being removed from the marina bed by excavator and transported a short distance by road to the temporary pool constructed in a field upstream, beyond the Power Station site.
The majority of the material will then be pumped along a pipeline back up the River Neb to the pool, which will be around 2.5 metres deep and will measure roughly 70m by 100m. This process will take place in the spring of 2019 and 2020, in order to avoid migrating fish.
The second stage of the project will see the material being temporarily stored in the pool for up 18 months. Excess water will be pumped back to the Marina after satisfying environmental standards agreed with the Department of Environment, Food and Agriculture (DEFA).
The third and final stage of the project will see the dried sediment used to restore contaminated and eroded land next to the former Cross Vein Mine, off the Roundtable Road, near Foxdale.
The sediment from the Marina is significantly less contaminated than the dust found at Cross Vein Mine and DEFA specialists are confident that the material will help reinstate the damaged land as an attractive upland habitat.
A comprehensive Environmental Impact Assessment will be undertaken and the remediation work will include measures to restrict further sediment loss from the site.
In doing so, this will reduce the amount of material entering the watercourses that flow into the Marina, where it causes significant and costly access restrictions. Reducing sediment flow is also likely to improve salmon and trout breeding locations in the Neb catchment.
A detailed transportation plan will be in place to ensure the safe transfer of materials from Peel to Cross Vein.
Tim Baker MHK, Member for the Department of Infrastructure with responsibility for Ports and chairman of the Peel Marina Project Board, said:
‘The proposed solution offers significant long-term benefits for both Peel Marina and the uplands. A lot of hard work and creative thinking has gone into getting us to this stage, and building the temporary pool will be the first stage in allowing it to succeed.
‘While the planning application is for five years, the intention is for the pool to be in place for a maximum of three, and the field will be restored after the project is finished.’
He added:
‘As this project takes place, further work will be undertaken to reduce the accumulation of silt and contamination levels in the Neb, with the DoI and DEFA continuing to work closely to ensure the best possible outcome for the environment.
‘It’s important to remember that this project is vital to the ongoing prosperity of Peel, and we are delighted that the solution provides wider environmental benefits.’
The plans will be placed on public display at Peel Town Hall in Derby Road, Monday to Thursday, 17-20 December. They will also be available to view on the planning section of the Isle of Man Government website.
The Peel Marina Project Board is working alongside Manx Utilities to ensure full consideration is given to the Peel Regional Sewage Treatment Strategy in addition to flood risk management in the area.
