Restoring saltmarsh on the Awre peninusla

Why Awre?

The land we’ve purchased at Awre is low-lying and at increasingly high risk of flooding. The land has flooded in the past, and farmers are aware of the danger to grazing animals when major flooding events do take place.

Left alone, an accidental breach of the defences would result in no recompense for landowners, the potential loss of all access to the site, loss of trees and shrubs, and potentially dangerous erosion.

Breaching the sea wall and allowing salt water from the estuary onto the land will begin the process of re-establishing the saltmarsh habitat that was present on the site centuries ago.

What phase is the project in now?

We are currently in the survey and design phase of our project at Awre. Our staff and independent ecologists are already conducting wildlife surveys on site including counting numbers of birds, bats and newts and we will be employing other experts to review things like archaeology, heritage, water quality, and landscape considerations.

Using the evidence collected in this phase alongside hydrological modelling work will help us to explore some of the possible layouts for the site. It will also help us decide things like the best location to breach the existing flood defences, where channels might be dug and what improvements we can make to ensure accessibility and bring benefits to the local community.

Once we’re confident that our designs will deliver good quality habitat and incorporate the feedback we have already received, we will present options for the community to consider and give us their thoughts on.

As our staff are already conducting wildlife surveys on site you may see WWT staff in the area more frequently in the coming months, as we continue to monitor these species as well as things like water and nutrient levels. If you see someone from WWT on site, please do say hello. We are always happy to answer any questions you have about the work we’re doing.

Project timeline

Progress to date

A timeline of project milestones from the initial donation to the present

What's next

Our anticipated dates for future milestones, some of which may be subject to change.

Your questions answered

Will saltmarsh form so far up the estuary?

Yes, and there are a few reasons we’re sure of this. There is already a large area of saltmarsh just across the river from Awre, at WWT Slimbridge. This saltmarsh type, known as Atlantic salt pasture, is an internationally important wetland habitat that supports an incredible array of wildlife, including large numbers of European white-fronted geese over winter.

Based on the elevation of the land we’ve purchased at Awre, we expect it to support a range of saltmarsh plants, from species that can survive frequent flooding with saltwater through to the grassy species that grow on higher areas of saltmarshes. This mix will change over time as sediment builds up and parts of the marsh are grazed, but all of them are valuable to different species and will significantly increase the biodiversity of the restored habitat.

We’ve also done our due diligence, measuring salinity, examining local history and looking for the kinds of plants we would want to see on the site. During a recent visit to Awre, we found colonies of a range of saltmarsh plants on the sediment in front of the defences and even directly in cracks in the sea wall. These plants are growing at sediment levels higher than much of the Awre peninsula.

Is this saltmarsh restoration, or saltmarsh creation? Has saltmarsh existed on the Awre peninsula before? When?

We certainly know that the peninsula was once an intertidal habitat subject to the ebbs and flows of the tide, because people have put in considerable effort to created flood defences across the land over hundreds of years. By looking at records, such as the 1840 tithe map, you can see many fields with names like Marsh and Wharf, saltmarshes along the Severn historically called variants of 'Warth'.

We understand that by the 1840s a new outer wall had been built to exclude the tide, but the names remained and, prior to exclusion of the tide, these marsh areas would have been saline to varying degrees.

Remnants of saltmarsh can be found on the southern side of the peninsula with salt-tolerant plants growing up to and on top of the flood defence wall. These plants are growing at elevations higher than a large swathe of the Awre peninsula, so we are sure that they would be on the land if the sea wall was not there. In addition,Slimbridge which is opposite the Awre peninnsula has fantastic saltmarsh of international importance.

We believe that where coastal defences are likely to fail in the future, and the terrain lends itself to restoration of saltmarsh or other intertidal habitats, it is much better to restore coastal habitats in a managed way than to delay until it happens accidentally. This is not least because the latter would potentially offer little support to landowners, fail to address the loss of footpaths and place infrastructure and buildings at risk.

What modelling are you doing to understand how your project at Awre will affect the flow of water in the wider estuary?

We’ve worked with expert consultants Jacobs, who are carrying out detailed predictions of how water will move across the site and through the estuary, known as hydrodynamic modelling, as part of the design process. Their early modelling work, which is informing design development, confirms that:

• the impact on tidal currents in the wider estuary from the breach will be negligible (less than 0.05 m/s on average);
• a breach will not have a significant effect on the extreme water levels in the wider estuary.

Jacobs use industry standard models, the kind used by the Environment Agency, so we have full confidence in them. It’s worth remembering that modelling confirms that the establishment of saltmarsh is possible and informs the process of designing a site but is only one aspect of what informs a final decision.

Will habitat restoration at Awre affect the Severn bore?

Our early modelling shows that the bore will still run as normal, because the wave will pass the entrance to the breach before the site begins to fill with water as the mid tide arrives.

While our modelling showed that there would be no significant impact on the formation or strength of the bore under any of the scenarios we considered we will do further modelling once we have a more detailed site design to factor in the potential effects that changes to topography across the site might have.

Are you just destroying one habitat for another?

The land we’ve purchased is mostly improved grassland – a land type that has often been ploughed, reseeded or fertilised and has a low diversity of species. There are some managed hedgerows, some mature trees and a large area of arable land for a maize crop.

We know that there are some species that will be using the existing hedges and mature trees to feed and nest, and we plan to plant new hedges at the upper end of the reserve to make up for those lost on the marsh.

As well as significantly increasing the area of saltmarsh to attract a huge variety of wildlife to the peninsula, we will also consider creating scrapes and saline lagoons, improving ditches and sowing wildflowers on the new flood bank. We’re very interested to hear from the local community about how to make the site attractive for the widest possible mix of wildlife.

Are you flooding productive farmland to create homes for wildlife?

Landscape-scale change within a rural community, especially one built on farming, will be felt more acutely and we understand the immediate concerns about the loss of farmland. The land we’ve purchased at Awre is very low-lying and at increasingly high risk of flooding. The land has flooded recently, and farmers are aware of the danger to grazing animals when major flooding events do take place.

We continue to work with farmers on the peninsula to graze and crop the land ahead of construction. While grazing will have to pause on the land during construction, we plan to work with local farmers to reintroduce grazing livestock on as much as the saltmarsh as possible, to allow those opportunities for food production. We do the same at WWT Steart Marshes.

Left alone, an accidental breach of the defences would result in no recompense for landowners, the potential loss of all access to the site, unmanaged and unmitigated loss of trees and shrubs, and potentially dangerous erosion.

Will you do archaeological investigations on site?

It’s highly likely we will have to do some archaeological work to determine whether, and what parts of, the site are of historical significance. Ridge and furrow farming has been present on the land for some time and these features are visible on Lidar maps. If areas of archaeological significance are found we will make sure these are properly recorded, and we will avoid creating creeks too nearby and allow silt to cover it to preserve them. Where feasible, we will not disturb these areas with construction equipment.

What about the footpath around the top of the flood embankment?

We realise the footpath around the edge of the Awre peninsula is highly valued locally and we will be working with Gloucestershire County Council on our application to provide a good alternative. Any new route we propose will connect the north and south side of the peninsula with a better surface, following the tow of the hillside and providing views across the site to the estuary.

The current footpath is under threat when the bank fails, and while a bridge across the breach has been suggested it is possible that existing flood defences will eventually fail in more than one place, making access to a bridge from one or both sides impossible.

We also know that disturbance is one of the biggest threats for birds on the Severn estuary, and limiting access to some areas of the foreshore will give migrating, wintering and breeding birds a safe place to retreat to all year round.

When will detailed designs be available?

We are still working on the detailed designs. We have done the initial feasibility, baseline and design work to understand the lay of the land and water, land ownership and other factors that could impact our plans. We continue to collect baseline information on the site (such as the species that already use the land), consulting with the community and statutory authorities, and are using this information to inform our plans.

Details about construction and when the site will be accessible to the community are still some way off, but we know these are really important. We’re very excited about showing designs to the community, but we also don’t want to present plans too early. Once we’re confident that our designs are ready to share, we’ll take feedback and seek to improve them further with valuable local knowledge.

As this project progresses, we’ll continue to provide answers to as many of your questions as we can. If you have any concerns or questions about the impact the project might have on you or someone you know in the community, please email us at saltmarshsolutions@wwt.org.uk

What is an Environmental Impact Assessment (EIA) and EIA Screening?

An Environmental Impact Assessment is a process required under the EIA regulations where a project is expected to have a significant impact on the environment. The EIA screening is where a local planning authority using the criteria as specified in the EIA regulations to decide whether a project requires a formal EIA. Not all projects require an EIA, though developments of major infrastructure or industry (for example, a mine, oil refinery or nuclear reactor) always do.

Why don’t you need an EIA for your project at Awre?

The Forest of Dean District Council published its decision that our project at Awre does not need a formal EIA in March 2025.

Not all projects require an EIA, and it is up to the Local Authority to determine where one is needed. Following the usual process for these kinds of developments the Forest of Dean District Council determined that as the physical works would be relatively short-term, that conditions could be imposed on any planning permission granted to avoid significant harm, that a significant effect is not likely and the kinds of monitoring and surveying required would be undertaken as part of the planning process, an EIA was not necessary in this case.

However, we will still be undertaking an extensive regime of monitoring and exploration of the habitats, wildlife use, water quality, soil, landscape and archaeology of the area and submitting this information as part of our planning application.

We will share our findings with the community as our work continues and we expect that the level of information we provide will be equal to what would be required for an EIA, although presented in a more accessible format.

You can read more about this decision on the Forest of Dean District Council’s planning portal here.

Planning documents

You can access planning documents related to our saltmarsh restoration project at Awre here:

Environmental Impact Assessment screening opinion

Contact

If you have any questions about our work at Awre please contact the project team at saltmarshsolutions@wwt.org.uk.

To keep up to date with our project at Awre you can follow us on Facebook here.