What is the Thames Valley Flood Scheme?

This page covers:

  • What the Thames Valley Flood Scheme is
  • Flood storage
  • Natural flood management
  • Funding
  • What other approaches did we consider?

In 2021 we held our first public consultation. You can view the information we shared, and our reports following the consultation on our reports page.


What is the Thames Valley Flood Scheme?

The Thames Valley Flood Scheme has been investigating ways to manage flood risk on a large scale across the Thames area. We have been looking at ways to reduce flood risk and build climate resilience for communities, businesses and infrastructure. The Thames Area is a large area as shown on the map below.

Over the course of the Thames Valley Flood Scheme, we have developed an approach to look into ways to reduce flood risk and enhance the natural environment at a scale that hasn’t previously been considered across the Thames catchment. Our work showed that large scale flood storage supported by natural flood management could reduce flood risk in the Thames Valley.

To find out about the scheme you can watch our video(External link), explaining the need for the scheme, what the scheme includes and our project ambitions.

We had previously found that creating new flood storage sites, supported by natural flood management, could work at a large scale to reduce flood risk. We had identified 17 locations that might be suitable to store flood water on some of the tributaries of (rivers that feed into) the River Thames. We found that large scale flood storage does have potential to help reduce flood risk to people and properties along the River Thames. However, the benefits in reducing flood risk would not be enough to gain funding and approvals. We are therefore not able to progress catchment scale flood storage at this time.


Where did we investigate for flood storage?

The scheme was set up to assess ways to reduce flood risk at a catchment-wide scale. We looked at the effectiveness of a range of ways to reduce flood risk, while improving sustainability and considering value for money. This led us to focus on large scale flood storage and natural flood management.

We initially assessed over 700 locations for flood storage and then narrowed these down to 17 areas for further investigation. These were locations where a flood storage area could be effective in reducing flood risk, while minimising impact on the local area. The 17 locations are shown as green dots on the map. You can find out about the process we followed by watching our video(External link) or reading our report and February 2024 newsletter.


Cost benefit review

We have reviewed the costs and flood risk benefits of using individual or small groups of flood storage sites to reduce flood risk. These groups are made up of potential flood storage areas on different tributaries of the River Thames. This cost review is a normal step for any large project. In this work, we compared the cost of building flood storage areas against the potential to reduce financial and societal damage from flooding downstream. This helps to determine whether a scheme is good value for money. For a scheme to go ahead, the benefits must significantly outweigh the costs.

Our initial findings from the review show that overall the benefits of flood storage only slightly exceeds the costs. Because the difference is small, we will not get approval to continue looking at large scale flood storage across the Thames Valley catchment.

Our work has shown that flood storage is important to reducing the flood risk of the Thames catchment at the scale needed in the face of climate change. However, the delivery of multiple flood storage areas under one scheme will not work. We will use the work we have done though the scheme to inform other future flood risk mitigation projects and partnership working in the area.


What could a flood storage area look like?

These paintings show an artist’s impression of a flood storage area. They show a generic location, rather than a specific place. In the painting above, you can see what the area might look like for most of the year. The image below shows what the flood storage area would look like when flooding is expected, with water being temporarily stored there. By storing water, we can reduce the amount of flooding and associated damage, financial costs and long-term mental health impacts.

Natural flood management

Our project team has been working to consider different approaches to incorporate natural flood management into the Thames Valley Flood Scheme.

There are lots of benefits of natural flood management. It can bring local flood risk benefits, enhance human wellbeing, improve water supply and quality, reduce drought impacts and improve the natural habitat. The Environment Agency and partner organisations have delivered many natural flood management projects across the Thames Valley, with others still in progress.

We are continuing to explore how we can support natural flood management work being completed by partners and communities across the Thames Valley. Natural flood management has many benefits beyond flood risk, and the Environment Agency will continue to support the great work already happening across the catchment.


Funding

Flood and coastal erosion risk management (FCERM) in the UK is funded from several different sources. The Government provides most of its funding for FCERM to the Environment Agency and other Risk Management Authorities as Grant-in-Aid (GiA). For many projects, including the Thames Valley Flood Scheme, where GiA funding does not cover all costs, the balance must be secured from private and public sector partners and the local communities and businesses that will benefit from the scheme. This is known as partnership funding, which is supported by the national FCERM Strategy as a means of delivering local priorities and providing communities and businesses with a say in what is done to reduce flood risk in their area.

The amount of funding a project can attract from different sources will depend on the benefits it provides. Considering the overall costs and benefits alongside the funding available, our catchment scale scheme is not considered feasible to take forward at this time.


What options did we consider?

We assessed 20 different approaches to see if they could work on their own to reduce flood risk across the Thames Valley. We identified that flood storage, circled in blue, will be a key part of the scheme. Natural flood management options, circled in green, could complement flood storage. These have potential to provide long-term benefits and meet the overall aims of the scheme, managing flood risk at a catchment scale. The other approaches shown on the diagram could still be used as part of the scheme, working alongside flood storage. To find out more please read our assessment of approaches report and our follow up report on natural flood management.




This page covers:

  • What the Thames Valley Flood Scheme is
  • Flood storage
  • Natural flood management
  • Funding
  • What other approaches did we consider?

In 2021 we held our first public consultation. You can view the information we shared, and our reports following the consultation on our reports page.


What is the Thames Valley Flood Scheme?

The Thames Valley Flood Scheme has been investigating ways to manage flood risk on a large scale across the Thames area. We have been looking at ways to reduce flood risk and build climate resilience for communities, businesses and infrastructure. The Thames Area is a large area as shown on the map below.

Over the course of the Thames Valley Flood Scheme, we have developed an approach to look into ways to reduce flood risk and enhance the natural environment at a scale that hasn’t previously been considered across the Thames catchment. Our work showed that large scale flood storage supported by natural flood management could reduce flood risk in the Thames Valley.

To find out about the scheme you can watch our video(External link), explaining the need for the scheme, what the scheme includes and our project ambitions.

We had previously found that creating new flood storage sites, supported by natural flood management, could work at a large scale to reduce flood risk. We had identified 17 locations that might be suitable to store flood water on some of the tributaries of (rivers that feed into) the River Thames. We found that large scale flood storage does have potential to help reduce flood risk to people and properties along the River Thames. However, the benefits in reducing flood risk would not be enough to gain funding and approvals. We are therefore not able to progress catchment scale flood storage at this time.


Where did we investigate for flood storage?

The scheme was set up to assess ways to reduce flood risk at a catchment-wide scale. We looked at the effectiveness of a range of ways to reduce flood risk, while improving sustainability and considering value for money. This led us to focus on large scale flood storage and natural flood management.

We initially assessed over 700 locations for flood storage and then narrowed these down to 17 areas for further investigation. These were locations where a flood storage area could be effective in reducing flood risk, while minimising impact on the local area. The 17 locations are shown as green dots on the map. You can find out about the process we followed by watching our video(External link) or reading our report and February 2024 newsletter.


Cost benefit review

We have reviewed the costs and flood risk benefits of using individual or small groups of flood storage sites to reduce flood risk. These groups are made up of potential flood storage areas on different tributaries of the River Thames. This cost review is a normal step for any large project. In this work, we compared the cost of building flood storage areas against the potential to reduce financial and societal damage from flooding downstream. This helps to determine whether a scheme is good value for money. For a scheme to go ahead, the benefits must significantly outweigh the costs.

Our initial findings from the review show that overall the benefits of flood storage only slightly exceeds the costs. Because the difference is small, we will not get approval to continue looking at large scale flood storage across the Thames Valley catchment.

Our work has shown that flood storage is important to reducing the flood risk of the Thames catchment at the scale needed in the face of climate change. However, the delivery of multiple flood storage areas under one scheme will not work. We will use the work we have done though the scheme to inform other future flood risk mitigation projects and partnership working in the area.


What could a flood storage area look like?

These paintings show an artist’s impression of a flood storage area. They show a generic location, rather than a specific place. In the painting above, you can see what the area might look like for most of the year. The image below shows what the flood storage area would look like when flooding is expected, with water being temporarily stored there. By storing water, we can reduce the amount of flooding and associated damage, financial costs and long-term mental health impacts.

Natural flood management

Our project team has been working to consider different approaches to incorporate natural flood management into the Thames Valley Flood Scheme.

There are lots of benefits of natural flood management. It can bring local flood risk benefits, enhance human wellbeing, improve water supply and quality, reduce drought impacts and improve the natural habitat. The Environment Agency and partner organisations have delivered many natural flood management projects across the Thames Valley, with others still in progress.

We are continuing to explore how we can support natural flood management work being completed by partners and communities across the Thames Valley. Natural flood management has many benefits beyond flood risk, and the Environment Agency will continue to support the great work already happening across the catchment.


Funding

Flood and coastal erosion risk management (FCERM) in the UK is funded from several different sources. The Government provides most of its funding for FCERM to the Environment Agency and other Risk Management Authorities as Grant-in-Aid (GiA). For many projects, including the Thames Valley Flood Scheme, where GiA funding does not cover all costs, the balance must be secured from private and public sector partners and the local communities and businesses that will benefit from the scheme. This is known as partnership funding, which is supported by the national FCERM Strategy as a means of delivering local priorities and providing communities and businesses with a say in what is done to reduce flood risk in their area.

The amount of funding a project can attract from different sources will depend on the benefits it provides. Considering the overall costs and benefits alongside the funding available, our catchment scale scheme is not considered feasible to take forward at this time.


What options did we consider?

We assessed 20 different approaches to see if they could work on their own to reduce flood risk across the Thames Valley. We identified that flood storage, circled in blue, will be a key part of the scheme. Natural flood management options, circled in green, could complement flood storage. These have potential to provide long-term benefits and meet the overall aims of the scheme, managing flood risk at a catchment scale. The other approaches shown on the diagram could still be used as part of the scheme, working alongside flood storage. To find out more please read our assessment of approaches report and our follow up report on natural flood management.




Page last updated: 21 Nov 2024, 06:36 AM