Oxford Flood Alleviation Scheme - Frequently Asked Questions

Closed 31 May 2021

Opened 17 May 2021

Overview

This page was created based on questions about the scheme we received through our survey in May 2021. We collated your questions into topics and responded to the most frequently asked. We will continue to update this page as new information becomes available.

We have also produced a video with members of the project team to answer some of your questions covering a range of topics. The video covers themes such as existing streams, environmental proposals and footpaths and access. You can watch the video here:

 

 

Latest News

The planning application for the scheme has been submitted to Oxfordshire County Council as the local planning authority. The council will hold an online public consultation from 7 April to 9 May 2022. All the information submitted to the council is available on their ePlanning system (Planning reference MW.0027/22)

Contact us

If you would like to get in touch or request to be added to our newsletter distribution list, please contact us at OxfordScheme@environment-agency.gov.uk.

Click on a topic below to be taken to that section.

Environment and wildlife

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Some of the environmental benefits of the scheme will be realised really quickly and others will evolve more slowly over time because the different habitats that we are creating will take different lengths of time to grow and establish. We’ve made sure that we’ve taken this into account when developing the environmental design and when setting out our short-term and long-term habitat management plans.
New streams, ponds and wetlands develop into valuable habitats very quickly, so within the first few months and years of the scheme being built we would expect to see the new stream and 20 hectares of wetland habitat developing really well. These habitats will then continue to develop over time and the variety of wildlife that they support will increase. They should quickly become an environmental asset for west Oxford.
We know that newly-planted woodland will take many years to grow before it develops the same ecological value as mature woodland. This is why we have designed the scheme to retain as many trees as possible. The number of new trees being planted will greatly exceed the number being felled, and the new trees will be planted and managed to create high quality woodland habitat. While the woodland is growing, it will support wildlife because developing habitats are important ecosystems in their own right.
We calculate biodiversity before and after the proposed scheme for the various habitats, and ensure there is an overall improvement, known as 'biodiversity net gain'. Our biodiversity modelling takes into account that habitats will take time to establish. We've carried out baseline surveys and we will continue monitoring the habitats and wildlife during and after construction. This environmental monitoring is currently funded for several decades post-construction, to ensure the environmental benefits are fully realised in the long term.
Find out more about the environmental benefits we hope to achieve on Page 2 - Environmental features of the scheme.

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The topsoil will be carefully stripped off and stored while we excavate the stream and lower the floodplain. Once the ground has been lowered, topsoil will be spread over the area again before it is seeded with grasses and wildflowers.

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Our plan is that an environmental organisation will manage the area to ensure that the habitats establish well and continue to improve over time. We have produced a habitat management plan and a long-term monitoring plan to ensure that this is the case.
Once the habitats have become established, it may be that they will meet the criteria required to become a local designated site such as a Local Wildlife Site or national designated site such as a Site of Special Scientific Interest (SSSI). This would be decided by the relevant authorities in the future.

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Yes, the scheme has been designed with the intention that much of the lowered floodplain beside the new stream will be grazed by cattle from April through to October and that the newly-created areas of species-rich floodplain meadow will be grazed after the hay has been cut in July. We intend to use low-density conservation grazing to strike a balance between keeping the vegetation under control and creating quality habitat. We have formed a collaboration with environmental charity Earth Trust who are helping plan the long term management of the scheme, including the management of the grassland and meadows.
For more information please see Page 2 - Environmental features of the scheme.
While the scheme is being built and once it is complete, it will be possible for Hinksey Meadow to be managed in the same way as it is now and this includes grazing once the hay has been cut. 

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Jacobs are the consultants who have carried out the majority of the ecological surveys on the scheme, with some of the specialist surveys carried out by their sub-consultants. We appointed specialist consultants directly to undertake the following surveys:
  • National Vegetation Classification (NVC) at Hinksey Meadow – Floodplain Meadows Partnership
  • Fish – Hull International Fisheries Institute
  • Aquatic Invertebrates – AECOM Ltd
  • Aquatic Macrophytes – Environment Agency, Analysis and Reporting Predictive System for Multimetrics (PSYM) at Kennington Pool – AECOM Ltd
In addition to carrying out the botanical survey work at Hinksey Meadow, the Floodplain Meadows Partnership of the Open University were also appointed to provide independent expert advice on how best to minimise impacts on Hinksey Meadow and provide replacement meadow where some loss is unavoidable.
We have also consulted a number of organisations and individuals throughout the development of the scheme in order to help us understand the likely effects of the scheme on the wildlife of Oxford and to maximise opportunities to deliver environmental net gain, including:
  • Freshwater Habitats Trust
  • Oxfordshire Badger Group
  • Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust (BBOWT)
  • RSPB Wetlands and Wildfowl Trust
  • Upper Thames Fisheries Consultative
  • Hogacre Common Ecopark
  • Trust for Oxfordshire’s Environment
  • Oxford Preservation Trust
  • Ecologists at Vale of White Horse District Council, Oxford City Council and Oxfordshire County Council
Jacobs have undertaken the Environmental Impact Assessment for the scheme and produced the Environmental Statement. This document explains how we have assessed all potential significant environmental impacts of the scheme, how we have designed the scheme to avoid significant impacts wherever possible and how we are mitigating for impacts which are unavoidable. The Environmental Statement has been submitted with the planning application along with all of the ecological survey reports.

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There are some very small areas of wetland habitat already present in the scheme area but ground levels are generally too high for this habitat to establish. When we lower the floodplain next to the Seacourt Stream and the new stream, we will be creating new wetland areas with a series of ponds, scrapes and backwaters. The new wetland will help to conserve the rare and varied freshwater wildlife found in and around Oxford and provide a link to other existing wetland sites to the north and south.
The 16 hectares of meadow created as part of the scheme will be species-rich floodplain meadow. Around 11 hectares of this will be created in areas of existing grassland, which is currently cut for hay, but which isn’t currently species-rich. We will increase the diversity of plants and grasses to create MG4 meadow. We will achieve this by lightly cutting up (scarifying) the soil in the existing grassland and spreading seeds or freshly cut hay over it. The seeds and hay will be collected from existing MG4 meadows nearby. We will then continue to manage the area as hay meadow with a cut in July. We also intend to introduce cattle to graze the meadow following the hay cut. This is known as aftermath grazing and it is part of the traditional management of hay meadows which helps to contribute to their diversity. Around 5 hectares of the proposed species-rich meadow has been managed as grazing pasture for many years. We will scarify and seed this area with MG4 and then manage it as hay meadow with aftermath grazing, as described above. We have tested the soil fertility and assessed groundwater levels in both of the proposed MG4 meadow areas to ensure that they are suitable for this habitat.

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Otters are present throughout the River Thames and its streams. We have carried out otter surveys of the scheme area, most recently in 2020. No holts (otter home sites) were found, but we did find evidence of otter feeding on the Bulstake Stream along with some ground resting sites. Before we start construction we'll conduct further surveys to identify any new active holts and resting/lying up areas and confirm if previously identified potential resting sites are active or not. This will define what we then need to do to ensure the otters are appropriately protected.
Otters are a European Protected Species and we will need to apply to Natural England for a licence if any of our work is likely to affect their breeding or resting places, or if it will obstruct access to their resting or sheltering places. We will ensure we allow sufficient time to finalise appropriate mitigation and apply for a licence from Natural England if necessary. While we are building the scheme, an Ecological Clerk of Works will be present during any vegetation clearance in and around suitable otter habitats. Works will stop immediately if it becomes clear that otters may be disturbed and appropriate advice will be sought from Natural England.
Otters have large defended territories covering many kilometres of river, and it is likely that only a very few animals will use the scheme area. An otter using the Hinksey and Bulstake streams is likely to forage on the main Thames as well, and given that they are predominantly nocturnal we do not envisage that the works will cause any substantial disruption to their foraging activities. Our main concern is to ensure any holts are identified which may be subject to disturbance or damage, and that robust safeguards are put in place. Once the scheme is finished, the new stream and wetland areas will provide new foraging habitats for otter and potentially more resting sites.

Trees

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We will remove trees only where we absolutely have to in order for the new stream and lowered floodplain to be created to reduce flood risk. We expect to need to remove around 2000 trees.
While designing the scheme, engineers, contractors, landscape architects and ecologists have worked together to minimise tree loss. We will also seek to further minimise tree loss when we are building the scheme. If it becomes clear that the contractor can work around trees that have been identified for felling without damaging them then they will be retained. An Environmental Clerk of Works will be on site and work alongside the contractor to make sure that these further opportunities are identified and taken wherever possible.
We will be planting over 4000 trees and ensuring an overall improvement in woodland quality after the scheme is in place.
For more information please see the section on 'Trees and hedgerows' on Page 2 - Environmental features of the scheme.

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We will plant saplings (young trees), which have a much better chance of establishing than replanting with older trees. As it will be many years before the new trees have the same ecological value as some of the older trees being felled, we've ensured our planting proposals account for this. The number of new trees planted will greatly exceed the number being felled, and the way these new trees will be planted and managed will lead to higher quality woodland habitat in the area after the scheme is in place than before.
As well as over 4000 trees we will plant many thousands of native shrubs and smaller-growing trees, such as hawthorn, hazel and elder, dogwood, goat willow, dog rose and wild privet. We will also be planting new hedgerow. The woodland areas will be managed for wildlife through traditional techniques such as coppicing which allows light to reach the woodland floor and encourages a diverse ground flora. The woodland areas will also include glades that are sown with wildflowers to encourage butterflies and other insects, as well as birds and foraging bats. This is in contrast to the majority of the existing woodland where the unmanaged, single age mature trees support only sparse shade-tolerant ground flora.
We calculate the biodiversity of woodland habitat before and after the proposed scheme is in place, and are ensuring we leave an overall improvement, known as 'biodiversity net gain'. In addition to improved woodland habitat, the scheme will also increase biodiversity of other valuable habitats, such as the creation of new wetland that will attract further new species.

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We will ensure the woodland habitat continues to improve over time and that newly-planted trees which do not survive are replaced where needed. We have submitted a Habitat Creation and Management Plan with our planning application. This sets out the short, medium and long-term landscape management objectives, activities and responsibilities for the scheme.
The new habitats, including trees and woodland, will be planted and initially maintained by a landscape contractor. Once the scheme nears construction we will tender for an environmental partner who will continue to maintain the habitats and landscape of the scheme after the landscape contractor has ensured initial establishment. The environmental partner will ensure that not only are the newly planted trees and woodland area properly maintained, but that they continue to be enhanced further into the future. We are dedicated to ensuring the scheme area improves the environment in the long term.
We have recently formed a collaboration with environmental charity Earth Trust who are helping plan the long term environmental benefits of the scheme.

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We have designed the scheme to minimise tree loss wherever possible and we have carried out ecological surveys so that we know which creatures are living in the area. Before we start site clearance and construction work we will undertake further surveys and an ecologist will supervise vegetation clearance on the site.
Before we build the scheme, nest boxes will be put up in woodland that is going to be retained. Trees and other vegetation that needs to be cleared will be removed outside the normal bird breeding season and this should encourage birds to build nests outside the scheme area, and possibly in some of the bird boxes. If breeding birds or nests are found on the construction site during the works then they will be left as they are until the young have fledged or the nest becomes disused. All work in the vicinity of a nest would be stopped immediately and we would put a construction buffer in place to avoid disturbance.
Trees with high-value for bats will be retained where possible but where felling is unavoidable, this will be done under ecological supervision and at a time of year when bats will not be present. New bat boxes will be put up before tree felling starts.
The full details of our plans for protecting wildlife have been submitted with our planning application as part of the Environmental Statement.

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The Kendall Copse area has many constraints we need to work with: the railway line, the A423, the A34, Kennington Road, Old Abingdon Road, the culverts under Old Abingdon Road which are a Scheduled Ancient Monument, overhead pylons, underground services, Kendall Copse Community Woodland and the Kendall Copse landfill site.
Kendall Copse West
In order to avoid the culverts on Old Abingdon Road, which are a Scheduled Ancient Monument, the new stream will flow under Old Abingdon Road, through the corner of Kendall Copse West and then under Kennington Road before passing through Kendall Copse East. We will need to excavate the new stream under Old Abingdon Road and Kennington Road, which will mean that each road will have to be closed for a period of time. To avoid unacceptable impacts on road safety while this work is carried out, we have had to design a temporary road through the western side of Kendall Copse. This will allow traffic to keep flowing at all times. This will also ensure that the local bus routes will not have to be stopped or diverted during construction.
In addition to the temporary road, we will need a construction compound in this area so that the contractor can carry out the work safely and, due to all the physical constraints described above, there is unfortunately no other practical location for it to go other than in Kendall Copse West, next to the A423. This will be a temporary compound which will be removed when the works are finished.
Kendall Copse East
The new stream will flow through the centre of Kendall Copse East so that it avoids the Scheduled Ancient Monuments and the railway line and ties in with the design of the new A423 bridge.
Once construction has finished in Kendall Copse, the temporary road and compound will be removed and we will plant the area with native trees and shrubs. Where we’re unable to plant as many trees as before, we will plant trees in other locations locally. We are also speaking to Kennington Parish Council to see if there are any local environmental schemes to which we can contribute. Although we will need to temporarily stop access to Kendall Copse during construction, we plan to provide public access to as much of the newly planted Kendall Copse as we can, once we finish.
Throughout the development of the scheme, the project team have attended several Kennington Parish Council meetings to explain the likely impacts of the scheme on local residents and to listen to any concerns.

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When we re-plant at Kendall Copse we will be using smaller trees and shrubs than those that we are replacing because smaller trees have a far better chance of establishing and surviving than older, larger ones. With less energy invested in their leaves and branches, younger trees are better able to quickly grow a root system that can support them and enable them to continue growing quickly. They will invariably overtake larger trees that are transplanted at the same time. When larger trees are transplanted it can take many years for their root system to recover and extend and quite often they do not survive the move.

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We have been advised that there may be a handful of trees in Kendall Copse that are of particular significance to the local community and that should therefore be transplanted to an alternative site. These trees would be clearly labelled and carefully moved by specialist landscape contractors under the supervision of an Environmental Clerk of Works.
The majority of the trees that need to be removed will be felled under the supervision of an Environmental Clerk of Works. As well as supervising the felling, they will identify further opportunities to retain trees wherever possible.

Grassland

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Our modelling has demonstrated that we need to lower the ground in order to create enough space for more floodwater to move through the fields. By lowering areas of the floodplain we will reduce flood risk to homes, businesses, roads, rail, and other vital infrastructure. In Hinksey Meadow, we need to lower the ground on the western edge of the meadow, next to the Seacourt Stream. We will keep the lowered ground here narrower and route it to avoid the rare grassland as much as possible. The extra space this creates will allow more floodwater to pass through and under the new bridge, which replaces the existing flood culverts under Willow Walk.
For more information please see the section on Grassland and floodplain meadow on Page 2 - Environmental features of the scheme.

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We have carefully considered how best to preserve the grassland found in Hinksey Meadow, which is a species-rich flood meadow that includes rare grass species such as snake's head fritillary. We appointed the Floodplain Meadows Partnership (FMP) of the Open University, as national experts in this type of grassland (known as MG4), to provide independent expert advice on how best to preserve the meadow and provide replacement meadow where some loss is unavoidable.
The area of MG4 grassland that will need to be removed to build the scheme has been kept to an absolute minimum. The 2 hectares of MG4 that needs to be removed will be carefully lifted by a specialist contractor and taken to a pre-prepared site with similar soil and groundwater levels. The new site will be managed as hay meadow, and the flowers, plants and insects in the transplanted turf will be monitored so that we can assess how well they are faring in their new home. We will make every effort to ensure the survival of the translocated MG4. However since there are no records of this operation having been carried out successfully to date, we will also create a large new area of MG4 floodplain meadow close by. Our aim is to leave the area with an overall increase in this valuable grassland, even if the transplantation itself is not fully successful. Our mitigation plan is explained further in the Grassland and floodplain meadow section on Page 2 - Environmental features of the scheme.

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We have considered how to maintain groundwater levels in Hinksey Meadow to help protect the rare MG4 grassland here. We will maintain existing water levels in the Seacourt Stream and Bulstake Stream under both low flow and average year conditions. This will maintain corresponding groundwater levels in Hinksey Meadow at or above existing levels. In the Bulstake Stream we will put in a series of gravel riffles (raised gravel areas along the stream bed) to help achieve this.
For more information please see the section on Grassland and floodplain meadow on Page 2 - Environmental features of the scheme.

Recreation and public access

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We will be creating a new track along much of the scheme to allow access for maintenance. A proportion of the track will be made into a permissive path that the public are allowed to use for walking or cycling. We are also building new bridges in the scheme area to ensure access is maintained over the new stream and wetland.

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We are building new bridges in the scheme area to ensure access is maintained over the new stream and wetland from North Hinksey. Please visit Page 2 - Background and Benefits > What is the scheme design for more details.

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While the scheme has not been designed for swimming or kayaking, the new stream will be accessible to small boats, canoes and kayaks.

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After the scheme is in place, walkers will still be able to use the public rights of way as they can now. They will also be able to use the informal path from North Hinksey to the Electric Road because a footbridge will be installed over the new stream. In addition, we are also creating a new access track along much of the scheme which will be made into a permissive path that the public are allowed to use.
A handful of public rights of way will need to be very slightly diverted in order to avoid the new stream, flood walls and embankments. Plans illustrating these permanent diversions are included in the planning application and we will be applying to Oxfordshire County Council for Diversion Orders.

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We will be creating a new track along much of the scheme to allow access for maintenance. A proportion of the track will be made into a permissive path that the public are allowed to use for walking or cycling. We are also building new bridges in the scheme area to ensure access is maintained over the new stream.
Visit Page 2 - What is the scheme design for more details.
Bridges in the scheme area

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We are working with our partner Oxfordshire County Council to explore if there are any opportunities to integrate the scheme with other initiatives.

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Willow Walk is currently a designated bridleway and is used by cyclists, pedestrians and equestrians and very occasionally the adjacent landowners. This will continue once the scheme is completed.
We need to construct a new bridge on Willow Walk over our new channel - this has been designed with all current users in mind. We are not proposing any other improvements to Willow Walk as part of the Oxford Flood Alleviation Scheme.

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The stone track known as the Electric Road (because it covers underground electric cables) runs from Osney Mead Industrial Estate to the Devil’s Backbone at South Hinksey. While we build the scheme our contractor will be close to the track in some areas, but it will not be closed. Once the scheme is constructed, access will remain as it is currently.

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The scheme maintenance track is in addition to the electric road.

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We do not own the electric road and we have no plans to tarmac it as part of our construction works.

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Willow Walk is a designated bridleway and will remain so once the scheme is in place.

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There will be some temporary closures and diversions of public rights of way and informal routes while we build the scheme. We will minimise disruption and always signpost alternative routes. When our contractor has finalised the construction programme we will have more details about the order and duration of these diversions.
While we carry out work at Willow Walk we are proposing to put in a temporary raised walkway running alongside Willow Walk. This temporary walkway will be suitable for pedestrians, cyclists and equestrians. We will also create a temporary path along the boundary of Seacourt Nature Park to maintain access between Botley Road and Hinksey Meadows while we work on the scheme in this area.

Scheme design

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Drawings of the scheme are available as part of our planning application. If you would like to see anything specific, please email us at OxfordScheme@environment-agency.gov.uk.

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The only new in-stream structure is one which controls the flow in the Eastwyke Ditch, which prevents water from flowing the wrong way at different water levels.
The scheme doesn't involve new weirs, lock gates or sluices to direct flood water into the scheme. During high water levels, floodwater on the fields north of Oxford is drawn into the lowered area of ground by the Seacourt Park and Ride. This forms the start of the Oxford Flood Alleviation Scheme which allows more floodwater to move through the floodplain rather than built up areas. The benefit of this design is that it is passive, and doesn't need to be actively turned on or off during floods using lock or sluice gates. You can find out more on Page 2 - How the scheme works.

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The 3 existing streams in the scheme area are the Seacourt Stream, the Hinksey Stream and the Bulstake Stream. As local people may know, the Seacourt Stream becomes the Hinksey Stream at Willow Walk.
Flows from the Bulstake Stream and the Hinksey Stream will combine to form the new stream just south of North Hinksey village. Up to where they combine, the existing streams will keep their existing alignments and flows. The scheme won’t affect flows upstream of the new stream. This includes on the Seacourt Stream adjacent to Hinksey Meadow.
Downstream of the new stream, the Bulstake Stream and the Hinksey Stream will continue to have water in them as they do now, but during dry weather there will be less flow.
For further information about the existing streams in the area and how they will connect with the new stream please watch the video at the top of this page.
Maintenance of the existing streams will continue to be the responsibility of the adjacent landowner, with the Environment Agency carrying out maintenance tasks such as clearing blockages as it does now. You can find out more about landowner maintenance here: www.gov.uk/guidance/owning-a-watercourse

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We have met with the Hinksey & Osney Environment Group (HOEG) on several occasions over the past few years to discuss their ideas, and we continue to look into some of their suggestions.

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Our scheme is designed to work with the natural floodplain. The Environment Agency designs passive flood alleviation schemes where possible. Passive schemes don’t need to be actively turned on or off during floods. They don’t have as many mechanical elements which might need fuel or have the potential to fail and need replacement, and need fewer operational staff to maintain the scheme in the long term. The Oxford Flood Alleviation Scheme provides a sustainable, long term solution for Oxford.

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The Oxford Flood Risk Management Strategy considered over 100 combinations of options to reduce Oxford's flood risk. As a result of the huge quantities of storage required and the costs involved, the Oxford Flood Risk Management Strategy concluded that an upstream storage area would not be a viable standalone option for reducing flood risk to the city.
Creating a new upstream storage area would not be an effective way to reduce flood risk to Oxford on its own. Because flood water can stay in Oxford for days or weeks, an effective upstream storage area, on its own, would need to store approximately 50 million mᵌ of water in the existing floodplain of the River Thames. This is equivalent to an area the size of Oxford 1 metre deep in water.

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The new stream will carry flowing water all of the time, including during the summer months. The scheme is made up partly of existing streams and new sections of stream alongside the lowered floodplain. You can find out more on Page 2 - How the scheme works.

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Our scheme relies on existing culverts underneath the railway. Constructing a new culvert under the railway would be very costly and extremely disruptive and is not needed for the scheme to function.

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There are no plans to compulsorily purchase the North Hinksey Lane allotments or any part of them.

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Dredging is an important part of maintenance but would not work to protect Oxford from a major flood. Even if we dredge all the rivers and streams in Oxford, it would not significantly reduce flooding from a major flood. Deepening channels around Oxford simply will not work, as excavating below the groundwater level would mean any extra space created simply fills with water. As there is barely any fall in land height over the 5km from Botley Road to Kennington, water will sit and silt will redeposit.
If done in the wrong place, dredging can damage the environment and increase flood risk downstream. The natural tendency of all rivers after dredging is to deposit silt and return to their more natural dimensions. This means dredging is inefficient and would need constant repetition. Each repetition causes further environmental damage without ever allowing full recovery. Frequent re-dredging would also be disruptive and expensive.

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Sustainable drainage does not form part of our scheme. We are creating ponds in the scheme area for wildlife. If you want to find out when SUDs are used you can contact enquires@environment-agency.gov.uk.

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Climate change is expected to cause more frequent and more severe floods. In the face of increasing flood risk due to climate change, the scheme will provide a long term solution to help manage flooding in Oxford for the next 100 years.

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The scheme will re-join the River Thames at Kennington, just downstream of the A423 ring road bridge. You can find a map of the scheme on Page 2 - What is the scheme design?

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The scheme is designed to work with the natural floodplain, by creating more space for floodwater away from built-up areas. We will construct flood walls and earth embankment in a small number of locations where properties would still otherwise flood. Constructing these defences without the extra space for floodwater in the lowered floodplain would risk transferring flood risk to other communities.

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The new bridge on Willow Walk needs to be big enough to allow the large volume of water that will pass through in a major flood to pass safely underneath - this is what dictates the span and height of the new bridge. The scheme is designed for major floods much larger than Oxford has seen in recent decades, of a scale not seen since 1947.
The new bridge also needs to accommodate occasional vehicle access for adjacent landowners to access their land as they do now, and the Environment Agency's maintenance vehicles, as well as being suitable for equestrians, cyclists and pedestrians.

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There aren’t any Thames Water outfalls into the new stream at this stage, and the sewer system runs throughout the area. Thames Water are one of the 10 partners on the scheme.

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The scheme is designed to create space for more floodwater to move through the existing western floodplain, not to provide additional storage capacity to hold water in the floodplain. By allowing more floodwater to move through the floodplain, the scheme will reduce flood risk to all existing properties at risk of flooding from the River Thames. In addition, Abingdon Road and Botley Road, the railway and other key infrastructure will also be at reduced flood risk. By moving floodwater away from built-up areas we can also demonstrate we do not increase flood risk to others.

Flood modelling and flood risk

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The scheme is designed to cope with a scale of flood not seen in Oxford since 1947. This is far bigger in size than any of the floods Oxford has experienced in recent decades. The scheme will provide Oxford with a much greater level of protection from large floods than it has now.
All properties currently at risk of flooding from the River Thames will see their flood risk reduced. In addition to reduced property flooding, the scheme will help keep the main railway line, Abingdon Road, Botley Road and local roads open in floods. There will be fewer flood related interruptions to essential utilities, including water, electricity, phone and internet. Schools and essential community services in flood risk areas won’t need to close during floods. Less disruption to road and rail travel around the city will help to keep Oxford open for business and support the tourist economy.
The scheme will not only lower the amount of financial damage caused by floods, it will also lessen the stress and trauma of flooding for residents and commuters, which can be devastating. Knowing that the scheme will help reduce risk during a major flood will give local people improved peace of mind from the worry of flooding.

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We use detailed computer modelling to design flood alleviation schemes and check they will work. We first create a baseline model of river flows that recreates water levels and flows using current and historic data and the dimensions of the rivers and streams. These are the models used to create flood risk maps (flood-warning-information.service.gov.uk/long-term-flood-risk). These models are calibrated using known previous floods, such as the records from the 2007 floods, to make sure that they reflect reality.
Using this model, different design options are then explored to work out the best way to reduce flooding. This is then translated into a ‘detailed design model’, built by design consultants and which undergoes independent expert review. Modelling continues to inform and refine the final details of the scheme design.
We also look at what has worked elsewhere. Similar schemes have been built to reduce flood risk by providing more space for water, for example https://qwag.org.uk/river-quaggy/flooging.

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We have ensured the scheme will not increase flood risk to properties downstream. We work to reduce flood risk, not to transfer it from one community to another.
The scheme will not hold back water (like a flood storage scheme) nor will it speed up water (like a deep narrow channel could do). We use detailed modelling, which is always independently verified, to design the scheme. This shows the scheme will not increase flood risk to properties downstream of Oxford.
As well as our own detailed modelling, our approach has been independently confirmed by the Vale of White Horse District Council.

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The model itself requires specialist software to use. We can share the outputs of our modelling in the form of flood maps or our Flood Risk Assessment. If you would like this or any other details, please email us at OxfordScheme@environment-agency.gov.uk.

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Flood risk to properties in Kennington (or any other location) will not increase due to the scheme.

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The scheme will reduce flood risk to all properties in Oxford currently at risk of flooding from the River Thames. On opening the scheme, the vast majority of these will be protected in a major flood, the size of which was last seen in Oxford in 1947. However, not all properties will experience the same level of flood reduction as this depends on where they are located in the current floodplain and their threshold level (the point at which floodwater will start to enter a property).

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Once the scheme is in place, all properties currently at risk of flooding from the River Thames on Abingdon Road will see their flood risk reduced. The scheme is designed to cope with major floods of a scale last experienced in 1947. This is far bigger in size than any of the floods Oxford has experienced in recent decades.

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All properties in Oxford currently at risk of flooding from the River Thames will see their flood risk reduced when the scheme is in place. We have not designed the scheme to prioritise any area above another.

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In major floods water will still use the wider existing floodplain which is mostly farmland and flood meadow. In fact this is an integral part of our overall solution. The scheme is designed to work with the natural floodplain.
The scheme does not increase flood risk to any properties. We conducted a Flood Risk Assessment (FRA) which demonstrates that there is no increased flood risk to properties as a result of the scheme.

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The scheme will reduce flood risk from river flooding (fluvial flooding) from the River Thames. It will reduce flood risk to all properties currently at risk of flooding from the River Thames in Oxford.
The risk of flooding from rain that does not drain away (surface water), or from water rising up above the water table (groundwater) will generally remain, but these can be better managed once river flooding is reduced.

Process and timescales

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Before we can start construction of the Oxford Flood Alleviation Scheme, we need to have all approvals in place, including planning permission and our compulsory purchase order to access the land needed for the scheme. To bring the scheme to Oxford as quickly as possible we value the support of local communities through these processes. The planning consultation by Oxfordshire County Council will be open to the public from 7 April to 9 May 2022. Once all approvals are in place, the scheme will then take between 3 and 5 years to build. We will update the public as soon as we have more details on timeframes and construction.

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We have used extensive computer modelling to ensure the scheme will work for Oxford. The concept of a new stream with lowered floodplain alongside has been used effectively in other flood schemes.

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We issue regular newsletters which are sent to local and regional media outlets. The scheme has been covered in the Oxford Mail, BBC Radio Oxford and BBC Oxford webpage.
In addition we regularly include articles in several local newsletters including the South Hinksey Echo and the Sprout newsletter which covers Botley and North Hinksey.
If you would like to sign up for our scheme newsletters please email oxfordscheme@environment-agency.gov.uk to ask to be added to our mailing list.

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More maps and plans of the scheme are available as part of our planning application, which is available on the Oxfordshire County Council website.

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We will be running a single compulsory purchase order (CPO) for all the land that we require for the scheme. A CPO process allows land and rights over land to be acquired when they are needed in the public interest. We expect to make our new CPO in 2022/23.
We always try to reach voluntary agreements with landowners where possible, rather than enforcing a CPO. If voluntary negotiation can be reached, the land is removed from the CPO once agreements are finalised.

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We have worked to develop the scheme together with partners and communities in Oxford. We held face-to-face public consultations on the scheme route in 2016 and the detailed design in 2017.
The purpose of our engagement in May 2021 was to update the public on progress since we had to withdraw our planning application, due to Oxfordshire County Council discovering the A423 Kennington Bridge needed replacing. The main design of the scheme is largely the same as we submitted in our initial planning application, which Oxfordshire County Council held 2 consultations on.
The new planning application for the scheme has been submitted to Oxfordshire County Council as the local planning authority. The council will hold an online public consultation from 7 April to 9 May 2022. All the information submitted to the council is available on their ePlanning system Planning reference MW.0027/22.

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We have not included cost comparisons to other scheme ideas in our planning application.

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We're confident the scheme remains the best overall solution to reduce flood risk in Oxford over the next 100 years. When first designing the scheme we considered over a hundred combinations of different options, and the scheme as designed was found to be the most effective and economic solution for Oxford. When the delay due to the A423 Kennington Bridge occurred, we used the opportunity to work with Oxfordshire County Council to improve the scheme in this area. In the time since we withdrew the previous planning application we've continued to progress aspects of the scheme and made minor amendments that improve this further.

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The scheme remains the best solution to reduce flooding across Oxford. We still require all consents and approvals, including planning permission to be in place before construction can start.

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Following the July 2007 floods the Environment Agency published a 3 phase plan to reduce flooding in Oxford over the next 100 years, known as the Oxford Strategy. The first phase, Oxford Short Term Measures was completed in 2014 when we installed new culverts under Willow Walk and near Old Abingdon Road and carried out enhanced desilting to a number of local streams.
The second phase of the Oxford Strategy was the Oxford Flood Alleviation Scheme - the current scheme. Whilst technically viable, the funding was not available at that time. The 2013/14 winter flooding coincided with the first review of the strategy - changes to how schemes are funded and the inclusion of climate change allowances meant the scheme could then progress. The increasing flood risk in coming decades due to climate change means Oxford needs a scheme to cope with major floods. We have been working on the scheme since.
A scheme of this size requires a number of statutory approvals to be in place before works can start, including both planning permission and a Compulsory Purchase Order. We had to withdraw our previous applications in early 2020 when issues with the A423 Kennington Railway Bridge were discovered. We have now modified our proposed scheme in this location and have submitted the new planning application to Oxfordshire County Council as the local planning authority. The council will hold an online public consultation from 7 April to 9 May 2022. All the information submitted to the council is available on their ePlanning system Planning reference MW.0027/22.

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The environment has been at the heart of our scheme proposals from the very start and has influenced the design process every step of the way. Whilst the primary purpose of the flood alleviation scheme is to reduce flood risk in Oxford and the surrounding areas, we have designed the scheme to also bring additional environmental benefits to the area, improving the local environment in the long term. The scheme will integrate sensitively with the existing landscape and create new wetland, which will link existing wildlife sites and increase biodiversity. Wetland habitats are in decline across the country and creating over 20 hectares of new wetland and around 16 hectares of floodplain meadow throughout the area will be a valuable benefit of the scheme.
We're aware that there are some alternative ideas being put forward by both individuals and groups in the community and take all of these proposals seriously. We originally assessed over 100 combinations of options to reduce flood risk in Oxford, and have spent time since in considering further suggestions. We remain confident that the scheme we’re putting forward is the best long term solution to reduce flooding across Oxford. Our key environmental objectives are for the Oxford Flood Alleviation Scheme to:
  • integrate into the existing landscape whilst maintaining the character of the pastoral floodplains and river meadowlands
  • minimise impacts on the existing environment and to fully mitigate or compensate for unavoidable impacts
  • achieve a net gain in biodiversity – leaving habitats with a greater variety of species than before
We believe that as well as reducing flood risk, the scheme will become a cherished environmental asset for the local community to enjoy for decades to come.

Costs

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The scheme is expected to cost around £150 million and is fully funded.

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The Government allocates funding to reduce flood risk across the country, as part of the annual national budget. The scheme will cost around £150 million. Having the scheme in place will save £1.4 billion by reducing flood damage and impact on the city over 100 years.

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The scheme will reduce flood risk to all houses in Oxford that are currently at risk of flooding from the River Thames.
There isn't a 'cost per house' of the scheme because properties have different flood risks and the scheme is designed to do so much more than reduce risk to homes. As well as helping protect houses, the scheme will reduce flood risk to businesses and is also designed to keep roads, railway and other vital infrastructure, utilities and services open and working in times of flood. The scheme will avoid almost £1.4 billion of flood damage over 100 years.
There are also less tangible benefits such as improved peace of mind that comes with reduced flood risk. Mental health impacts of flooding are severe, you can find out more about the cost associated with this here: www.gov.uk/flood-and-coastal-erosion-risk-management-research-reports/a-method-for-monetising-the-mental-health-costs-of-flooding
Flooding of properties, and closure of roads and rail have occurred even in the relatively small floods we have seen in recent decades with the floodplain as it is. Climate change will mean floods are likely to be regular and more severe in coming decades. This is why we want to increase the amount of water than can move through the floodplain to reduce flood risk to built up areas.

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The Oxford Flood Risk Management Strategy looked at over 100 combinations of options to reduce the risk of flooding in Oxford. These ranged from non-structural measures such as flood warnings, to natural flood management measures, to full engineering interventions such as raised flood defences. The options were identified through consultation with specialists, flood action groups and local residents. The current scheme was found to be the most effective and economically viable scheme for Oxford.
The Environment Agency is in the early stages of developing the Thames Valley Flood Scheme to manage flood risk across the wider Thames Valley, for more information visit their webpage and respond to their consultation.

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The scheme is fully funded by over £88 million of central government money and the remainder from partnership and third party contributions.

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In the 2020 budget, the government committed to doubling expenditure on Flood and Coastal Erosion Risk Management (FCERM) to £5.2 billion between 2021 and 2027 (HM Treasury, 2020). The Oxford Flood Alleviation Scheme is one of the key flagship schemes within our programme and the funding is secure.

Construction

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We will be constructing a temporary road through the western side of Kendall Copse near Kennington. This will allow 2 way traffic to keep flowing at all times on Old Abingdon Road and Kennington Road during construction. Please see Scheme updates - New temporary road for more details.

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We will reuse as much of the excavated material such as earth and gravel as we can on site, for example in earth embankments and environmental features. Most of the material leaving the site will be transported to old quarries that have planning permission for restoration. Once planning permission for the scheme has been granted we will be able to confirm which sites have the capacity to receive the material.

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We plan to remove some of the excavated material such as earth and gravel by rail, but this depends on a separate planning application being successful and commercial agreements with the operator of Hinksey sidings.
Find out more about our plans on Page 3 - Potential transport of material by rail.

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If we are able to use rail, our proposal will be to build a temporary haul road from the works to the railway sidings. We will submit a separate planning application for this temporary road and any changes needed at the railway sidings.

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The railway sidings are already operational. As part of our Environmental Impact Assessment, we will consider the impacts of the new haul road to the railway sidings and the changes that need to be made to the sidings. This will cover air quality and noise.
One of the requirements of planning will be a construction management plan that will cover these issues. Find out more detail on this on Page 2 - How will the scheme be built.

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The new stream will typically be around 8 metres wide, with this width varying to give the type of profile that occurs naturally, being up to 15 metres wide in some locations to provide environmental features. The new stream will connect with the existing stream network including the Seacourt Stream, Bulstake Stream and Hinksey Stream and will meander through the floodplain to re-join the River Thames.
The ground around the new stream will be lowered by around 1 metre from existing ground levels, with a gradual incline at the edges back up to the original ground level. This will create a gently sloping floodplain which will be seeded with grass and wildflowers and include an extensive network of freshwater features including ponds, scrapes and backwaters. This lowered ground next to the new stream will vary in width throughout the length of the scheme - in places it will be typically 150m wide. In other areas, where space is more restricted it will be much narrower.
The overall quantity of excavated material to be removed from site is 365,000m³ or approximately 700,000 tonnes.

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We will re-use much of the excavated material on site, for example in earth embankments and environmental features, and we’ll retain some topsoil to help vegetation recover after construction. We will still need to transport around 365,000m³ of material out of the area. We cannot leave it in the floodplain, so it will be moved off site to be used for landscape restoration in previously excavated quarries.
The majority of the excavated soil will be removed from site by lorry on to the A34 near South Hinksey. We are also investigating removing some material by rail, but this depends on a separate planning application and commercial agreements with the operator of Hinksey sidings. The number of lorry movements will depend on how much material can be taken by rail. The details of material management and lorry movements will be in the Material Management Plan and Transport Assessment of our planning application.
Find out more about our plans here on Page 2 - How will the scheme be built?

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The A423 bridge is owned by Oxfordshire County Council. You can find out about their plans here: www.oxfordshire.gov.uk/residents/roads-and-transport/roadworks/future-transport-projects/a423-kennington-bridge-works.

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We need to excavate under Old Abingdon Road and Kennington Road in order for the new stream to pass under both these main roads. This will create 2 new bridges for the new stream to flow underneath.
Our work avoids the medieval culverts under the Old Abingdon Road, which are designated as Scheduled Ancient Monuments. We won't be impacting this archaeology and our works in this area will require an archaeological watching brief, ensuring the archaeology is monitored and recorded if encountered.

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During construction of the scheme we will need to temporarily occupy a section of the existing Redbridge Park and Ride, near the A423 Oxford Southern Bypass. This area will be used as a site compound for our works in this location. We are in discussions with Oxford City Council to minimise impacts on Redbridge Park and Ride, with a view to ensuring a large part of the Park and Ride will still be available for public use. Further details are included in our planning application.

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We will construct a temporary haul road for construction traffic throughout the length of our scheme, running from Botley Road to Old Abingdon Road. Our main access point to connect the haul road with the road network will be at the existing A34/South Hinksey junction. As the floodplain narrows towards South Hinksey this will require vehicles running between the edge of the village and the National Grid sub-station (located near the Devil's Backbone Footpath).
The haul road will be in operation for the duration of construction which will between 3 and 5 years. This is detailed in our planning application.

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Our contractor has taken into account the risk of flooding occurring during construction and planned the programme with this in mind - for example, we will not excavate the new stream during the winter months when flood risk is at its highest. However, floods can happen at any time and our contractor manages this risk through their flood risk plans which set out various measures to minimise the impact should this occur. This includes the use of the existing temporary flood barriers, such as those used in South Hinksey, if required. Temporary barriers can continue to be used if needed while we build the scheme.

Long term management and legacy

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We have recently formed a collaboration with environmental charity Earth Trust who are helping plan the long term maintenance and environmental benefits of the scheme. This will ensure that the scheme’s landscape and habitats are carefully maintained for the lifetime of the scheme, but also that they continue to establish and improve further in the long term.
Once we near construction, we will work in partnership with a local environmental organisation to ensure dedicated specialist resources for this long term habitat maintenance. They will also ensure there are opportunities for local people to be involved in its management and future use, and will promote opportunities for health and wellbeing and scientific research.
For more information please see Page 2 - Environmental features of the scheme.

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The cost of maintenance over 100 years for both the flood scheme and surrounding landscape, including specialist habitat establishment, is included in the Environment Agency budget.

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Our partnership with Earth Trust will help us plan the long term maintenance of the new landscape and habitats, ensuring the scheme provides a green legacy for the local area.
Earth Trust will develop an overarching strategy for how the scheme will benefit the environment over its lifetime. This strategy will include a habitats plan, environmental management and work with local communities. We will work collaboratively with Earth Trust for the coming years, to establish a plan for longer term engagement with scheme neighbouring landowners, communities and stakeholders to support our environmental objectives.

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The new stream will carry flowing water all of the time and because the stream meanders and is not over-widened the amount of water flowing through will keep sediments moving through natural river-processes.
Most of the space for floodwater is created by the lowered floodplain. Watch our video on how the scheme works here.

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One of the ambitions of our Environmental Vision is to connect people with the scheme. This will especially benefit local primary school children to have such a location within walking distance of their school and homes. We'll be working with the environmental charity Earth Trust on these plans to provide access and opportunities for education.
For more information please see Page 2 - Environmental features of the scheme.

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Audiences

  • Recreational and commercial river users
  • Fishing clubs and representative associations
  • Members of the public with an interest in the river, the species and conservation
  • Businesses
  • Charities
  • Statutory organisations
  • NGOs
  • Members of the public
  • Elected representatives, including MPs
  • Local councils
  • Academics
  • Environment Agency customers
  • Environment Agency colleagues

Interests

  • Flood management
  • Habitats and wildlife