Initial Project Scoping

Key Points: 

• High Fen was purchased by Nattergal in 2022 due to its potential to be a restored lowland fen, its hydrological isolation and historically low agricultural productivity. 

• The site’s hydrology plans have been the main determinant in its wider ecological planning, such as areas of peat rewetting and wetland mosaic restoration. 

• Baselining took place in the first year of ownership which included a UKHab survey, peat coring, species surveys and LiDAR.  

• This data helped show that a combination of Peatland Code and Biodiversity Net Gain unit sales would be most appropriate as revenue streams, spatially allocated across the site according to different parcels’ ecology, soils and hydrology. 

• Nattergal has worked with many local project partners, including local landowners, landscape partnerships, and its county council (on the Local Nature Recovery Strategy), to access shared learnings and other opportunities.  

• Permitting has been a significant challenge for High Fen, with some applications taking over 12 months to secure.  

 

Landscape and Original Land Use  

High Fen is located within the Norfolk Fens. Since the 17th century, the Fens have been drained to convert the region for major arable farming developments, due to their abundance of peaty, fertile soils. It is one of the most productive agricultural regions in the UK. However, this intensive farming has had a significant impact on the Fens’ biodiversity levels, natural hydrology, carbon storage and sequestration capabilities. 

A visualisation of this productive agricultural land has been provided by DEFRA’s Multi-Agency Geographic Information for the Countryside (MAGiC).  

Figure 1: Map of Soil Grade across the Norfolk Fens (MAGiC) 

Like its surrounding area, High Fen has an abundance of deep and peaty soils, and was historically used for arable farming. However, the land was eventually taken out of arable cultivation due to low productivity – linked to its soils and seasonally inundated ground. It was at one point a daffodil farm, and most recently had sheep and horse gazing, while being managed under Countryside Stewardship, primarily for wet grassland wading birds. 

High Fen has a complex hydrology. The River Wissey, which runs along the western boundary, supplies much of the site’s water. However the Cut-off Channel to the north and east, which was constructed in the 1950s as part of regional flood defence infrastructure, diverts water that would have naturally flowed from the higher ground of the Norfolk Brecks. The combination of peat and chalk soils contributes to a complex hydrological environment, with seasonal variability and water retention challenges – which the Nattergal team describes it using a ‘leaky bathtub’ analogy.  

Despite these challenges, one of the unique advantages of High Fen is that it is hydrologically isolated, meaning that rewetting can be carried out without affecting neighbouring landowners or requiring their permission, which is typically seen as a massive barrier elsewhere. 

Nattergal acquired the site in 2022 after it was put on the open market and brought to their attention by a local farmer, who highlighted its potential for wetland restoration.  

Matthew Hay, Natural Capital Project Manager at Nattergal, says that the team did not have much ecological data at the time of acquisition. However, High Fen’s size, hydrological isolation, and habitat composition made it appealing: “we were enraptured by the site, and could see that it was desperately trying to revert itself to a natural wetland state.” Nattergal also considered the site’s potential for the Peatland Code’s upcoming lowland fen protocol, through its Version 2.0, which was published in 2023. 

Figure 2: Map of High Fen 

 

Vision for the Land and Initial Baselining  

In its ambition to fully rewild the site, Nattergal set out with two major aims: 

1. to rewet as much of the site as possible, preserving its lowland peat soils, and;
2. to increase the species diversity and abundance on-site. 

Following acquisition, Nattergal commissioned a UKHab Survey with eCountability, and commissioned peat coring with Agricarbon to identify the site’s peat soil presence (but not depth), showing that 60% of the site is peatland. The Freshwater Habitats Trust also provided an assessment of flora species presence – concluding the site had poor biodiversity levels – and guidance on creating a resilient wetland system. Finally, Nattergal teamed up with an experienced hydrologist, Dr Nick Haycock, to further investigate the site’s complex hydrology. These initial assessments took around three months over the summer of 2023.  

Hay stresses that LiDAR and borehole excavations were both crucial for understanding the site’s re-wetting potential. Understanding the movement and behaviour of groundwater on the site, highlighted were drainage was occurring and shaped the restoration plans. 

While these assessments showed clear potential for habitat restoration and rewetting, they also revealed key considerations. For example, this monitoring immediately ruled out the potential of rewetting the upper, eastern half of the site due to its natural supply and drainage. Nattergal also discovered that the site had very high densities of badgers (36 sets), which were likely impacting the breeding success of previously abundant ground-nesting birds.  

Hay comments that, two years on, Nattergal is still building its understanding of the site and its hydrology, but was able to form a more detailed plan with this initial baselining within the first year. Detail on its more extensive baselining can be found in Milestone 3. 

After this first year, the visualisation of the future for the site was illustrated by Digg & Co. depicting the restored habitats of the site and the reintroduction of various native species. Hay comments that this illustration has been highly useful in stakeholder engagement.  

Figure 3: Illustration of High Fen’s Potential Future State (Digg and Co) 

 

Nature market and revenue scoping 

Once Nattergal received its peat depth and UKHab survey results, peatland carbon and Biodiversity Net Gain (BNG) unit sales were identified as the two most likely revenue sources. 

For peatland carbon, Nattergal used the Peatland Code’s Field Protocol to understand what areas of the site would be eligible under its new lowland fen protocol. For example, the lowland fen protocol does not accept areas of peat soil depth less than 45cm. With Nattergal’s ecological assessments, this  criteria initially ruled out around 150 hectares of the site.  

Nattergal also considered BNG unit sales, including those linked to high distinctiveness floodplain wetland mosaic, medium distinctiveness scrub and grassland. The UKHab survey (geared towards BNG’s habitat classification) helped Nattergal to understand the more easily improved habitats that could generate a higher BNG unit uplift. High Fen is also located in a large National Character Area, which gives Nattergal an advantage in selling to developers across up to 11 Local Planning Authorities (see below). This gave Nattergal initial confidence of a sufficiently large pool of demand. 

Figure 4: High Fen’s location within the Fens NCA (in green) (Natural England) 

Nattergal initially considered an ecotourism offering and  is open to exploring this again in the future. 

Nattergal will calculate the water benefits created by restoring High Fen, and will price in these benefits to the carbon and BNG units. In time the water services may be sold as a separate benefit if additionality can be proved. High Fen represents an excellent site to study and develop new methodologies for commercially realising water benefits provided through rewilding.  

 

Influential Partners and Local Initiatives 

Hay comments that High Fens’ neighbouring farmers and landowners have played an invaluable role in shaping the project and educating the Nattergal team about the Fens, sharing long-term knowledge. 

More formally, High Fen is part of the Ouse Washes Landscape Recovery (LR) Project, which is developing a 20-year partnership coalition across 4,000 hectares. This has offered shared learnings with other landowners, opportunities to create a ‘rewetted corridor’ with neighbouring landowners, and funding for some minor baselining activities. 

High Fen is also a partner in the Fens East Peatland Partnership, administered by Lincolnshire Wildlife Trust. This has offered shared learnings with other major fens rewetting projects, such as Wicken Fen, but has also given Nattergal access to an internal database of different contractors and service providers relating to fens rewetting. This has been particularly useful where Nattergal has been required to use a tender process for selecting contractors – which is a requirement of Natural England’s Peatland Grant Scheme, which Nattergal secured for the site (see below). 

Finally, Nattergal has engaged with Norfolk County Council on its Local Nature Recovery Strategy (LNRS), which is due to be published by the end of 2025. High Fen has been formally recognised as an area of strategic significance within the LNRS, which will mean the creation of a higher number of BNG units (through the metric’s strategic significance multiplier). 

Further partners on High Fen’s later baselining and modelling can be found in Milestone 3.  

 

Legal, Permitting, and Tax Considerations 

High Fen is not designated under any conservation classifications, but the team has addressed several permitting requirements. These include:  

• archaeological investigations and reports,  

• protected species mitigation for its bund construction, 

• flood risk activity permit (pending), 

• water abstraction licences (pending).  

Hay says that permitting has been a slow process that has required patience and continuous effort. For example, Nattergal has undertaken intensive water vole mitigation, and Hay is currently giving feedback to Natural England on the process’s challenges. Nattergal also requires a winter water abstraction licence, due to the fact the River Wissey has been disconnected from its floodplain and continues to be artificially drained by the Cut-Off Channel. This additional winter water will have the added benefit of increasing the site’s resilience to climate change. The abstraction license is expected to take up to 15 months to secure. 

Nattergal has legally bound the site using a conservation covenant, with the Lifescape Project as the Responsible Body. Though only required for its BNG sites, Nattergal has chosen to apply its conservation covenant across the whole of the site – including for its peatland restoration areas – to ensure greater confidence in the permanence of the project.  

No significant tax implications were identified during early planning. However, accounting considerations include income recognition and amortisation of costs. 

 

Funding project development 

Nattergal has largely used its own funds, including the company’s equity, to cover costs across the Project, including land acquisition costs, permitting and legal costs, baselining and ecological planning fees.  

High Fen has also secured a grant from the Nature for Climate Peatland Grant Scheme, which will cover almost 75% of the costs associated with rewetting the carbon areas, as is permitted within the Peatland Code’s additionality rules.  

 

Figure 5: A photograph of Willow carr in High Fen Wildland (Nattergal)