What to look out for at Forge Dam over the next 2 weeks
It has been a rather eventful few months over at Forge Dam and the work is almost coming to an end! Our target of extracting 5000 tonnes of silt has now been met, meaning de-silting of the millpond has now finished. As you know, the removed silt has been taken off-site to use as cover material for a closed landfill at Beighton, in our green-to-green remediation partnership.
You will have seen that some of the silt has been spread over to the North side of the dam to form depths and shallows on the base of millpond. This landscaping will create habitat to accommodate a variety of water-loving species. Some silt will also be used for profiling around the edges of the island, including creation of a kingfisher bank.
Work is just starting on the next phase of the project, the formation of a sinew channel. This will create a deeper channel for the brook to run in, encouraging water to flow predominantly down the spillway. A training wall will separate the channel from the millpond, which will be constructed of interwoven bundles of hazel and alder harvested from the site. Ten foot tall king posts will form the rigid structure, the first of these posts went in yesterday, which you can see in this picture. There will be inlets and outlets within the wall to allow water to circulate between the brook and dam, and over time this will develop into a natural river bank.
Aidan and Luis from Sanctus Ltd considering checking out the first two “king posts” for the sinew channel.
Some of you may have noticed last Friday that a plume of silt was visible in the river below the spillway, after the contractors encountered the historic maintenance hatch at the base of the weir. Unfortunately a metal cover which should have prevented silt escape had long since corroded. The contractors immediately stopped work and took remedial action to block the hatch and thankfully, our silt mitigation measures (such as the silt nets you can see downstream) caught most of the release. The Environment Agency has advised us on further measures to prevent accidental silt migration downstream during these last stages of work.
Update on the Path Repair
You’ll see that sadly the north bank footpath remains closed and will be until the Council can effect repairs on the collapsed section of wall. This will take place as soon as possible and we will keep you updated as this progresses, and really apologise for any inconvenience. Please keep in mind that the area to the rear of the collapse has been shut off for your own safety and avoid crossing that area, despite how tempting it is to take the short cut.
Hopefully the weather continues to stay lovely, and you get a chance to have a look at what’s going on in these final stages of work. Although once all the heavy machinery leaves the site, that will not be the end of the restoration. Look out for an upcoming blog about the longer-term conservation and environmental improvement plan for the area, which will include formation of so called ‘leaky dams’.