Questions and Answers
Wetland Restoration Work at Afton Marsh (North and South)
Freshwater Parish Council received an update on the works at Afton Marsh last night at our full Committee meeting. We have included the latest question and answer information about the works due to begin this month – November 2024.
- Who manages the marsh?
Natural Enterprise, as part of their Gift to Nature portfolio of open access sites, manages the marshes on behalf of IW Council.
As a Site of Special Scientific Interest (SSSI) the marsh is monitored by Natural England and is subject to clear set of management prescriptions.
The Environment Agency leads on all matters pertaining to the river.
- What is a SSSI?
SSSI are some of the finest sites for wildlife and natural features in England, supporting many characteristic, rare and endangered species, habitats and natural features.
The marshes are possibly still the best, if now much diminished, example of base enriched fen on the Isle of Wight and mainly comprise areas of tall-fen vegetation dominated by Common Reed with small blocks of Willow and Alder.
This embryonic section of the River (Western) Yar is fed by base-rich water, welling up from the chalk aquifer at the southern (upstream) end of the SSSI and flows the length of the site to enter the tidal reaches of the estuary via tidal gates at the northern extremity of the marsh.
- Why is the work necessary?
To restore the marsh and recover its biodiversity value.
Intervention is required to reverse the natural succession that has occurred over many decades. The fen, reedbed, marsh and swamp have been invaded by willow scrub and a larger cover of woodland (birch, oak etc.) over the drier ground.
The river and many ditches are heavily shaded by scrub.
A literature survey in 2017 concluded that many of the species recorded pre-1950 were likely to no longer be present due to the drainage work to dry them out. The scrubbing over of the marsh has further reduced the number of fenland species in the area.
- What work is to be undertaken?
The reed swamp is to be restored by the removal of invasive willow scrub and the woodland improved by selective felling to create open areas and rides. Where possible, to stop regrowth, the willow scrub will be left to dry and then burnt on site on a purpose-built platform so the ash can be removed from site. Larger cord wood will be removed from site if possible or used as habitat piles if more appropriate.
Work to improve the condition of ditches is to be undertaken to establish open clear successional habitat whilst not lowering the water-table.
Introduction of a stock-proof fence in order to reinstate a conservation grazing regime. This will both manage the existing areas of fen and re-create former areas.
Improvements to the paths, which are periodically flooded and often very muddy, will make access easier for visitors to the reserve.
- Where will the work take place?
The majority of the work will take place on the South Marsh, but some scrub clearance will occur on the North Marsh.
- When will the work commence?
It is expected to start in November 2024 and, subject to weather and ground conditions, to be completed spring 2027. No tree / habitat work will be undertaken during the bird nesting season.
Why are you taking trees down when we need more trees not fewer?
The aim is to improve the woodland area by selective felling to create open areas and rides. A Forestry Commission consent has been obtained to undertake the tree work.
Natural Enterprise are a great supporter of tree planting. However there is a recognised principle of ‘the right tree in the right place’. Wetlands are very valuable habitats for wildlife but are under threat and in decline. Wetlands already store carbon and planting trees on them can dry them out and cast shade, resulting in a net loss of biodiversity.
For every tree removed Natural Enterprise intends to plant two trees on one of our other Gift to Nature sites or provide trees as part of a community tree giveaway scheme.
What are the potential impacts on the ecological features during the work?
We have identified and put in place mitigation plans for the following:
- disturbance of species due to increased presence of people, vehicles, noise and vibration
- disturbance of species due to site access routes
- planned site improvement operations
- potential non-standard operations e.g. one-off incidents and accidents.
- What precautions will be taken to protect the wildlife?
To reduce the risk of harm to species, work will be carried out during the winter when water voles and birds are least active.
The site surveys (A. Rothwell 2020) indicate that Water Voles are not present on the site however each area being cleared will be monitored beforehand and during the work for any indication of protected or any other species. The Gift to Nature Rangers who are trained in Water Voles surveying.
The highly sensitive areas will be identified prior to commencement of works and be flagged and removed from the work imprint. Suitable temporary and permanent on-site receptor sites will be established and cleared for access, should removal be required during the work.
In sensitive areas, work will only take place on one side of any water course at any one time.
Where access is possible, habitats will be strimmed up to 6 weeks in advance to make them undesirable for reptiles, water voles, insects etc.
Natural Enterprise will acquire a selection of buckets and other receptables that can be used for temporary or permanent removal of animals, flora and fauna if required.
- What other precautions will be taken?
An active inspection regime will be adopted throughout the duration of the work and, where sensitive species are identified, work will be amended, delayed or not undertaken.
Tree works will be carried out using best practice, trees being monitored and checked for Bat and any other activity before commencement of any works. Any Bats found to be present will be recorded and the area clearly marked and avoided. Any larger trees to come out as part of the project will be marked with a spray to identify them.
The work will be under the direct supervision and direction of the Gift to Nature Senior Ranger.
- What Biosecurity measures will be in place?
The person in charge of Biosecurity will be the Gift to Nature Senior Ranger.
All members of the workforce will be made aware of how important biosecurity measures are and their adherence will be monitored throughout the project.
Effective cleaning of soil and other debris from tools, equipment, footwear and clothing will be undertaken before leaving a site. No direct site-to-site movement to take place without thorough cleaning. Wherever possible vehicle movements will be kept to a minimum and equipment not moved between sites during operations.
- Can people still walk through?
- Yes, although there may be some short-term periodic restrictions on health and safety grounds.
- Who is funding the work?
As part of Natural England’s role, they are funding the work under a Countryside Stewardship Agreement. - Couldn’t the money be better spent?
The funding was secured on a competitive basis with the work considered by Natural England to be environmentally important. It has been a long-standing aim to improve the marsh and therefore we feel very fortunate to have secured this funding.
North Marsh
- Why is there so much water on the North Marsh?
The in flow of water from the South Marsh, the source of the Western Yar, is greater than the outflow at Afton Road. As a result the water table on the North Marsh has risen. This has affected all the marsh between the Causeway and Blackbridge Road.
The outflow of water is controlled by the Environment Agency and is governed by their management regime for the area.
- Why hasn’t the river been dredged like it used to be?
In natural river systems the floodplain temporarily stores, slows and absorbs floodwater. A dredge river will not hold as much water as its floodplain. It is better to allow a river to connect with its floodplain rather than dredge. This also has many ecological benefits.
Also dredged silt tends to be deposited on the riverbanks. This means that the river becomes deeply incised (Eastern Yar along the cycle track at Horringford) and if the water does top the bank, the water finds it very difficult to get back into the river again, because of the barrier of dredgings. A dredged river has a faster flow and can cause erosion and flooding downstream. It’s just a quicker way to move the problem from A to B. A better approach is to make space for water.
- Has the new path caused the increase in the water table?
No. The increasing water table has been occurring for a number of years and was a driver for the new path to allow people to have better access the marsh. The rainfall during the last two years has increased the pace of change. The increased water table has lifted across the whole marsh not just the areas adjacent to the path.
The reason for the higher water table – please see above
- Why are the trees dying in the North Marsh?
This reflects the changing habitat conditions. As a result of the increase in the water table the vegetation is re-adjusting and species such as sycamore and willow scrub have suffered at the expense of marsh grasses and reeds, which are already starting to return. Our site management regime supports this approach.
- If I have questions at any time who do I contact?
Graham Biss, Managing Director, Natural Enterprise
Tel: 01983 296244 or