Making a difference for freshwater in North Buckinghamshire
17th October 2024
Freshwater Habitats Trust Project Officer Siân Vincent talks about her experience running the North Bucks Freshwater Resilience Project. She reflects on her experience of designing and overseeing the creation of ponds, wetlands and natural flood management features across North Buckinghamshire.
Can you tell us about the North Bucks Freshwater Resilience Project and what it is trying to achieve?
As the first project I was involved with at Freshwater Habitats Trust, it has been a fantastic opportunity to work with the local farming community and our key partners, Buckinghamshire Council, to enhance the freshwater environment of North Buckinghamshire. We’ve focused on creating and restoring wetlands to address the ongoing decline in freshwater biodiversity and reducing local flood risk through Natural Flood Management (NFM). NFM aims to increase water storage in the landscape by mimicking natural processes that slow down water and reduce the risk of flooding.
What are the issues affecting freshwater habitats in North Buckinghamshire?
In common with other rural areas in lowland England, we are seeing ongoing declines in freshwater wildlife and habitats, and increasing flood risk, caused by land use intensity, climate change, extensive land drainage and modification of small watercourses.
Our landscape surveys of wetland plants have revealed that many plants sensitive to water quality are now extinct in the area, so imminent action is needed if we are to prevent further losses. Despite this, Buckinghamshire still has areas of high-quality habitats left, which support many plant and animal species. Through the project we focused on building out from these existing biodiversity hotspots.
What work have you carried out so far?
Working with 13 landowners at six farms across North Buckinghamshire, the project has implemented over 70 NFM and habitat improvement measures. Restoring freshwater habitat such as fen and wet grassland and creating new habitats – including ponds and wetland mosaics – is bringing clean water back to the landscape to support rich and diverse communities of freshwater species. We let these habitats naturally fill and become colonised by plants and animals over time.
Using natural processes and materials, we created features to hold back and slow the flow of water through the landscape. These measures included leaky dams and bunded storage areas, which temporarily store water in sensible places to reduce downstream peak flows. The impact on flow reduction can be maximised by combining these measures where appropriate.
- Sunset at Swanbourne wetland by Roger Parker
We have now moved into a monitoring phase, evaluating the impact of the measures we have put in place, for example using cameras and dataloggers to capture water depth and understand how NFM features react during storm events.
Can you tell us a bit more about the NFM measures you used in this project?
We used a number of different types of NFM measures. This included creating leaky dams in watercourses to hold back water during storm events. Building a leaky dam involves embedding large timbers into the riverbank, leaving a gap below so that normal flows are not impeded. Leaky dams can store water within the channel and can also be used to push water back onto the historic floodplain.
We incorporated tree hinge dams, which are created by cutting partially into the trunk of a bankside tree and folding it across the stream, a bit like hedge laying. The tree remains alive and takes root into the opposite bank, strengthening the structure overtime. The branches sticking into the water create ‘roughness’ and slow the flow of water, but also provide great invertebrate habitat and refuge for fish.
Lastly, on some sites we introduced a bunded storage area, which is essentially a bank constructed out of clay soil (a bund) to hold water within a low-lying area of land. Water can then slowly drain back into the watercourse through a pipe or dug-out connection channel.
What did you enjoy most about the project?
My favourite aspect of the project was having the satisfaction of seeing my own designed habitats being created before my own eyes – to see something you spent days or weeks drawing up and designing come to life in front of you really is a great feeling. The impact and benefit of creating a pond or wetland may not sound like a massive thing, but it feels like such a direct way to help nature and uplift biodiversity – it feels so real and rewarding.
I also enjoyed the way I could see the project all the way through. This meant I experienced each aspect from start to finish – from the initial landowner introductions and walkovers to the data collection and designs, acquiring quotes and writing contracts, overseeing the practical works, and of course building relationships with contractors and landowners along the way.
I had a lot of responsibility which felt good, and due to juggling so many different tasks, I had to frequently problem solve – especially out in the field where things easily go wrong. For example, we were affected by heavy rain and flooding making the ground too wet to work with. We also experienced diggers and other machinery getting broken, finding field drains here there and everywhere, and water flowing where you don’t expect it to. It felt like I was always solving a puzzle which kept my job very interesting.
Lastly, I really loved the intellectual challenge of designing NFM features. I would do walkovers across farmland, taking photos and using a laser level to take elevation measurements, and used elevation data to calculate and visualise where water would flow and collect within the landscape. It feels like such creative work, using the existing topography such as slopes or historic river ‘palaeo-channels’ and the contours of the land, along with natural materials such as timber and clay all sourced from the same site. And even better, seeing these features in action makes it all the more satisfying.
- A rainbow over Swanbourne wetland by Roger Parker