The Bog Squad has recently been working with students from Oatridge College to carry out peatland restoration work at Black Moss by Armadale. The students helped to build eight ditch-blocking dams over the course of three sessions.
Four of the dams built were made from the peat itself. Despite being infilled with vegetation and partially decomposed material, the old ditches are still carrying water away from the moss. This causes the surface vegetation and upper peat layers to dry out, damaging them and making the site vulnerable to fire. Compressed peat forms a good barrier to water flow so peat can make an excellent damming material.
To create the peat dams, a one metre section of ditch was excavated to a depth of around one metre, crucially below the original depth that the ditches were dug out. Then a borrow pit where good quality peat could be excavated was dug beside the ditch upstream of the dam. 'Good peat' was cut in spade sized chunks, packed into the excavated ditch and regularly compressed. Once slightly above the level of the ditch it was topped with the previously removed turves. The borrow pit was then infilled with the decomposed material removed the ditch.
One major advantage of peat dams is that no materials are needed, however they are a labour-heavy method when being hand-dug. An alternative is to use interlocking plastic piling sheets that can be driven vertically into the peat. These create a good seal and can be installed quickly, even by hand. On the downside they are relatively expensive at £7-8 per metre of material.
All in all eight good dams were constructed, holding water and re-wetting this corner of Black Moss. Not only protecting the a range of peatland wildlife but also helping safeguard the vast store of carbon in the moss. Many thanks indeed to the students of Oatridge for their efforts.