Filling in history

Flanders Moss NNR

A lot has happened to Flanders Moss over time. Between 1750 and 1850 there was a concentrated effort to remove the whole bog. In the end only (!) about 40% was removed, mainly from the east side. This was because it was essentially in the way and not good for making money. So huge areas were drained, cut up and flushed down the rivers. And though this work stopped in the mid 1800s, mainly due to economics, we can still see the impact today. On the east side of Flanders is a ditch that was probably dug first about 200 years ago and has been draining water off the moss ever since. In more recent years it has been enlarged by peat extraction companies  and has generally been having quite a negative effect on the moss. If we were ever going to restore the moss back to its former dripping wet glory then this ditch had to be dammed.

Click on this link to see a copy of an old map showing the length of ditch being dammed (red line). You can also see the boundary of Flanders Moss today (bold black line) and the extent of peat that has now been cleared.

Flanders – double ditch historical map  

But you never start damming a ditch at its bottom end: first of all you block all of the feeder ditches as this means that there are less big flows of water once you block the main ditch.  Once these smaller ditches were dammed we could turn our attention to the main ditch. It was not a straight forward task as it had been running for so long, drying out the area, that it had caused cracks and slumping either side of it. By just damming the ditch all you would do would be divert the water into side cracks and bypass your dam. Eventually, using the expert knowledge of OpenSpace – peatland restoration contractors – a plan was devised and put into action. This involved putting in 15 large plastic piling dams across the ditch but sealing up the edges and cracks using a technique called deep trench bunding. This involves a big digger building a wall of wet, squashed peat under the surface of the bog which seals any flow lines for water. With the dams and nearly 2km of bunding the result is that the ditch that has drained water off the moss for 200 years is no more. There is still a flow line of water there but it flows at the surface of the moss rather than 2 m down. And to add to the complexity of the work, adders used the ridge of dried peat next to the ditch for hibernating so to make sure that we didn’t affect them we had to plot where their hibernaculum were and work around them. They seemed to have approved as they were found coming out of hibernation after the works were completed.

Of course, this is just the start of the recovery process and it is going to be fascinating to watch the spread of sphagnum moss and the recovery of the site.