18th February, 2021
Recent events on Whitehorse Hill, Dartmoor, including the damming of the Higher Phillpotts Peat Pass, have raised a number of concerns and highlighted the vulnerability of this world-renowned cultural heritage. The creation of expansive, deep pools calls into question the effectiveness of this strategy as a means of restoring peatland on the moor.
The Hangingstone Project extends well onto Whitehorse Hill and the ‘Hangingstone’ Phase 2 project is concerned with Whitehorse and Black Hill rather than Hangingstone. This draws the public’s attention away from the fact that digging is occurring in an internationally-recognised cultural landscape. The whole hill is highly sensitive and not yet fully understood with many unrecorded features yet to be revealed, so every penetrating excavator bucket is potentially destroying archaeological remains. The policy should be one of minimum intervention and active archaeological research in the area and should be taken into account in any future plans. We feel that environmental priorities and the protection of our cultural heritage can both be achieved.
An example of how intrusive intervention could inadvertently damage such monuments is the recent building of the dam at the head of the Higher Phillpotts Peat Pass, creating a large pool of water that was in danger of lapping away at the foot of the peaty mound containing the Whitehorse Hill Cist. We don’t currently know if the mound contains any associated burials or other features. While there is some logic in efforts to raise the water table to protect such sites, these organic remains survived for over 3,500 years, in spite of being exposed above the surrounding water table for at least a century. Their survival at this level must have been due to the frequently mist and rain-soaked environment (neighbouring Black Hill had nearly 145 inches of rain in 2020: source Mike Sampson) and it is only since its disturbance and all the attendant publicity that the surrounding peat has rapidly eroded away – in a mere ten years. In our opinion, the creation of deep-water pools in the vicinity will do little to restore its peatland setting, or to protect it in the longer term in such an exposed location.
On Monday 8th February, a group of us visited Hangingstone Hill to see the latest works. We found crossing the hilltop quite treacherous on the frozen ground, buffeted by the strong wind while negotiating the narrow bunds between these newly created deep pools. The safety of solitary walkers (and livestock) is a serious concern. We understand that the bunds were deliberately designed with a profile to enable a person or animal to get out but these proved ineffective when Chris Chapman broke the ice and entered one of the pools in his waders with a ranging pole. This pool was over 1.5 metres deep not that far from the edge. This also raises questions of duty of care and liability with hazards having been deliberately created.
Assessment of the degree of erosion
We have long questioned the historical basis for the assessment that the blanket peat is being eroded to the extent it is claimed, or that the erosion gullies are a new phenomenon. While we respect the science underpinning this, we dispute the interpretation of the evidence used as the basis for the assessment, which is in part based on aerial photographs taken by the RAF in April 1947. This was the year of the severe blizzard and a long period of freezing temperatures, following which deep sheets of snow lay on the higher ground, especially in the gullies, well into the early summer. This shows clearly on the aerial photograph but could easily be mistaken for sheets of water or level ground surfaces when analysed by a computer. It also has the effect of distorting the apparent definition and depths of the gullies, thus having a significant impact on their interpretation. Other, satellite and LiDAR, imagery clearly shows the softening of the edges of old peat ties where the peat is regenerating and this process can be seen on the ground.
We understand the logic of attempting to raise the water table in order to ‘re-wet’ the existing peat. It is harder to understand how the creation of large, deep, open pools on exposed hilltops will encourage new peat to form. Continuous surface disturbance will hamper any vegetation growth and hinder the formation of new peat. With the constant movement, the edges of the pools will erode and more methane could be released from the bare floor beneath, in addition to that released by the initial machine excavations. By contrast, adjacent to one particularly large artificial pool, complete with frozen waves on the surface was a similar area of naturally regenerating peat in a slight hollow, with profuse and varied vegetation growing on the surface.
There are legitimate concerns about the long-term effects of climate change on the health of peatlands due to drying and erosion but we believe that this is the wrong approach for this situation. The exposed uplands of Dartmoor experience some of the highest precipitation in southern England and so the use of a ‘one size fits all’ approach that may well work on drier, more sheltered environments are totally inappropriate for Dartmoor.
An alternative approach may be to find alternative proven methods of establishing peat regrowth. For instance, the establishment of ‘sphagnum nurseries’ in old peat ties on the Somerset Levels could enable commercial peat extraction companies to diversify in a more environmentally-friendly way by producing pre-seeded mats or organic gabions of sphagnum and other suitable plants. These could be sensitively-placed on upland areas like Dartmoor to form shallow pools in sheltered gullies, thereby encouraging natural regeneration and providing local employment/business opportunities here – all for significantly less cost to the taxpayer.
We believe that there should be an immediate pause in scheduled works in order to evaluate the effectiveness of the methodology and the attendant risks to public safety and hidden archaeology. We believe that the review should include a study of the natural regeneration of peat occurring in the vicinity. This will point to ways that we can work with nature to encourage this process. We would willingly collaborate and consider contributing to a study that considers alternatives, and we hope that the current method of creating deep pools will cease until a consensus is reached.
We would support a less invasive approach, drawing on experiences in other areas. We believe it is possible to meet the aims of all involved. Can we organise a joint symposium, with the aim of bringing together all interested parties to present new evidence and find a mutually agreed way forward?
Alan Endacott MA
Acting Chairman, The Dartmoor Society