Natural Flood Management, Dartmoor Spring Mire Restoration
“With climate change, what we need to do is quite daunting, but there’s huge potential. I’m excited to be working here: there’s huge opportunity.”
We’re balancing in wet pools, peering down at the wonderful world of mosses and plants that thrive in wet land. Around us, there’s the sound of slowly trickling water, as streams flow gently down the hill. It hasn’t always been like this; until recently, especially if there had been heavy rain, water would rush past quickly, increasing the chance of flooding in the valleys, and draining precious bog habitats on the moor. Now, work to slow the flow of water is beginning to heal a land that has been scarred by industry and erosion.
We’re on Harford Common, a high moorland on Dartmoor’s southern edge, where work to protect and restore spring mires has been underway for some time as part of a Natural Flood Management (NFM) programme. This is an area that’s been affected by past industries and interventions. Centuries ago, gravel was dug out from streams so that tin could be extracted; this left wide gullies. Then came a railway, and a series of drainage channels, which further affected the flow of water. The legacy of these interventions is a landscape where water flows downhill fast, instead of being retained, and the land is vulnerable to erosion.
Last summer, commoner Philip French took us up to see the hard landscaping that’s been done to reduce run off from a large area of bog (mire) that’s fed by the springs here. The new wooden fencing helps to channel water differently and encourages the cattle to drink without entering the mire.
We’re back now with Angelique McBride to find out about the next stage of the process, which has been to put in a series of leaky dams a little further down the moor. The work here is helping to restore the wetland habitat, something that not just restores the home for plants and insects that need wetlands, but will also help to protect against the degradation of peat. Over time, with wet conditions and the growth of moss, new peat will be able to form here. This is really important, given the extreme peat degradation across Dartmoor - the University of Exeter estimates that just 1% of Dartmoor's original peatland is still intact.
Angelique works for Dartmoor National Park as a natural flood management officer on the Dartmoor Headwaters Project. We’re up here with her just a month after a series of leaky dams had been put in place below the spring mire. The impact, over such a short time, is quite incredible.
We begin by taking a close look at the mire, which since our visit with Philip has already changed. The amount of sphagnum moss has grown, and we spot some red and yellow sundew, raising their sticky heads towards the sky. There’s a channel of water running alongside the track that sits just below the mire - the channel offers water for cattle, so that they are tempted away from the mire and reduce pressure on that.
Angelique talks us through the hydrology, or the flow of water. ‘When you start draining the water away, you're concentrating the flow. And when you concentrate the flow, you're not going to have a lateral movement of water; instead, you have channels funnelling water away as quickly as possible. And when you change the hydrology, you're also changing the habitat, you’re changing the mire so you don't have pockets of standing water, you won't have sphagnum growing.’ This is an ideal state for a mire, and the aim of the project is to restore this.
“There needs to be a variety, and rewetting the land and introducing sphagnum will change the habitat here so there’s a mosaic of vegetation. Water is really key in that.”
Angelique has been working for several months with a wider team to shore up the land where the erosion has been severe, and to install the dams. School children have been involved as well, helping to introduce sphagnum moss into areas of pooled water. We’re all in wellies - essential footwear here - and tread carefully to get close, and look at the dams and the pools that are forming. It’s not just moss that’s taking hold; lots of water-loving vegetation is growing here. ‘This area is dominated by acid grassland - it’s a good habitat but there's a lot of it of it on Dartmoor. There needs to be a variety, and rewetting the land and introducing sphagnum will change the habitat here so there’s a mosaic of vegetation. Water is really key in that.’ Before the dams were put in, water would have drained away in a single channel; now it’s spreading in pools. This is the result she’d hoped for.
We spend a few hours with Angelique. I am fascinated to learn about the process of rewetting land, and why it’s important; and even more interested to see just how much has happened within a month of installing the dams. The strategy that has been used draws on learning elsewhere in Dartmoor and around the country: getting the angles right, allowing just the right amount of water to pass through each dam, and allowing space between a successive series of dams. We’ll be back again in months and years to come, to see how the area continues to change.
After we’ve sloshed in and out of pools and talked about the intricacies of hydrology and the challenges of rewetting land, we pause and look around: out across the moor in one direction, and into the wooded valleys in the other. I ask Angelique how it feels to be working here.
‘Even though Dartmoor is quite a small place,’ she says, ‘it’s big enough that it makes me feel very small. It feels majestic, and out here, I feel at peace, with nature. But then I also see how bare it is, and how it’s dominated by Molinia, and I know I could do something good for Dartmoor. But it’s not about going in with some kind of dogma. It's a case of understanding what it looks like now, and why people like it this way, and explaining that we're heading into a different age. What we're seeing now is not going to be here for ever, if the climate is changing, so there's no point keeping it like it is - it needs some changes to be resilient.’
This idea of resilience, and imagining a future for the moors, is shared by everyone we meet here. We are often inspired by their infectious passion about a place, whatever their special interest or expertise, whatever their story. Some people are following in the footsteps of previous generations, others have just arrived; some people are sceptical and worried, others are optimistic. I ask Angelique, who admits to being a newcomer, how she relates to Dartmoor now.
‘I didn’t grow up here,’ says Angelique. ‘Coming to explore, walk, camp and have fun with friends, at first I felt like, gosh, this landscape is untouched, and how beautiful, and I don't want it to change it … but now that I'm working on the moor and learning about the history of it, I see it differently. My baseline has changed. With climate change, what we need to do is quite daunting, but there’s huge potential. I’m excited to be working here: there's huge opportunity.’
Find out more … Links for the curious:
Dartmoor Headwaters Project
https://www.dartmoor.gov.uk/wildlife-and-heritage/our-conservation-work/dartmoor-headwaters-project
Peat restoration work on The Forest of Dartmoor
https://foundationforcommonland.org.uk/commons-stories/dartmoor-peat-restoration
Read more about restoration of blanket bog further up the moor, on the Forest, in this post: https://foundationforcommonland.org.uk/commons-stories/dartmoor-peat-restoration