Posted on Dec 21, 2023

High Flood Risk Areas and Flood Mitigation in England

With climate change impacting our weather patterns, we’re seeing more extreme weather events in the UK and worldwide year on year.

Over the last five years alone, the UK has battled an array of storms, including the ‘Beast from the East’ (March 2018) when a blizzard hit the UK, Storm Ciara and Bella in 2020, Storm Darcy and Arwen in 2021, Storm Eunice in 2022 with gusts of up to 92mph, and most recently Storm Babet causing some of the worst flooding we have seen in many years.

With homes, commercial properties and farmland under water, our team of experts have delved into Environment Agency data to identify the UK areas facing the biggest risk of flooding based on the locations with the most flood alerts over the last five years.

The team also discuss how flooding on such a scale can be prevented in the future by implementing a range of solutions that may help to solve this difficult issue.

Based on the number of flood alerts and flood warnings over the past five years, the top ten flood risk areas in England are:

  1. West Midlands (4107)
  2. Wessex (3397)
  3. Yorkshire (2608)
  4. Solent and South Downs (1789)
  5. Essex, Norfolk and Suffolk (1608)
  6. Kent S London and E Sussex (1456)
  7. East Midlands (1256)
  8. Cumbria (1195)
  9. Devon (1074)
  10. Thames (1050)

Let’s break it down:

1. West Midlands

Our study revealed West Midlands is the region with the highest flood risk factor, having experienced severe flooding during winter periods in 2019 and 2020 in particular. Heavy and persistent rain, combined with saturated ground, led to significant river and surface water flooding in the region.

The region received a total of 4,107 alerts during the last five years and experienced the most alerts in Severn Vyrnwy Confluence (87), followed by Upper Avon River Swift and Clay Coton Brook (85) and River Churnet and River Tean (80). See a full breakdown of the ten most at-risk locations in the West Midlands below:

Rank Warning / Alert Area Name No. Flood Alerts
1 Severn Vyrnwy Confluence 87
2 Upper Avon River Swift and Clay Coton Brook 85
3 River Churnet and River Tean 80
4 River Sow and River Penk 77
5 River Leam and River Itchen 76
6 River Blythe in Warwickshire 72
6 River Stour and Smestow Brook in the Black Country and South Staffordshire 72
8 River Wye in Herefordshire 66
9 Upper Teme 57
10 River Cole 55

2. Wessex

With 3,466 flood alerts and warnings spanning the past five years, our research found Wessex to be the second highest flood risk. In November 2019, Wessex was affected by widespread flooding. Towns and villages were badly affected, which led to heavy disruptions and property damage.

Key areas most at risk include Somerset Coast at Porlock Weir with 176 alerts in total, Christchurch Harbour (101), Tidal River Avon at Bristol, Pill and Shirehampton (89) and West Bay Harbour (81).

Rank Warning / Alert Area Name No. Flood Alerts
1 Somerset coast at Porlock Weir 176
2 Christchurch Harbour 101
3 Tidal River Avon at Bristol, Pill and Shirehampton 89
4 West Bay Harbour 81
5 East coast of Dorset 76
6 South East Somerset Rivers, Upper Reaches 70
7 West coast of Dorset 68
8 Dorset coast at Poole Harbour 64
9 West Dorset Rivers and Streams 58
10 West Somerset Streams 56

3. Yorkshire

Yorkshire received 2,608 flood alerts and warnings in the last five years. Just this year, the area was greeted by Storm Otto, the first named storm of the 2023 storm season. The storm brought gusts of over 69mph to parts of North East England and Scotland.

Since 2018, 176 areas within North East Yorkshire received flood alerts; Humber Estuary from Spurn Point to Winestead Outfall received the most warnings with 163 alerts, followed by the North Sea coast at Withernsea, Easington and Kilnsea (142), North Sea Coast at Bridlington (132) and North Sea coast at Hornsea (98).

Rank Warning / Alert Area Name No. Flood Alerts
1 Humber Estuary from Spurn Point to Winestead Outfall 163
2 North Sea coast at Withernsea, Easington and Kilnsea 142
3 North Sea coast at Bridlington 132
4 North Sea coast at Hornsea 98
5 North Sea coast from Staithes to Whitby including tidal River Esk 77
6 North Sea coast from Whitby to Filey 71
7 Upper River Ouse 66
8 Lower River Swale 58
9 North Sea coast at Skipsea, Hornsea and Mappleton 55
10 Tidal River Ouse from Naburn Lock to Selby 54

4. Solent and South Downs

The Solent and South Downs region in the southern part of England has experienced various floods over the years, although they might not always receive as much attention as larger urban areas. According to our research, the region received 1,789 flood alerts and warnings between June 2018 and June 2023.

The southern area experienced the most alerts for Eastern Yar (117), according to the data, followed by Climping Seafront (79), Cuckmere River (58) and Western Rother (56).

Rank Warning / Alert Area Name No. Flood Alerts
1 Eastern Yar 117
2 Climping Seafront 79
3 Cuckmere River 58
4 Western Rother 56
5 River Blackwater 53
6 Upper Ouse 51
7 Mansbridge and Riverside Park 47
8 River Uck 45
9 Langstone to Emsworth Harbour 44
10 Combe Haven 39

5. Essex, Norfolk and Suffolk

Across Essex, Norfolk and Suffolk, there were 1,608 flood warnings and alerts spanning across the last five years. One of the most devastating flood events in the history of the UK, the North Sea Flood of 1953, severely impacted Essex, Norfolk, Suffolk, and other regions along the eastern coast. Due to the region’s geographical vulnerability, flooding remains a high concern, with frequent possibility of high spring tides, strong winds, and low-pressure systems.

Between 2018 and 2023, the Essex coast from Clacton to and including St Peters Flat and the Colne and Blackwater estuaries had the highest number of flood alerts (131).

Rank Warning / Alert Area Name No. Flood Alerts
1 The Essex coast from Clacton to and including St Peters Flat and the Colne and Blackwater estuaries 131
2 The tidal River Yare from Thorpe St Andrew to Breydon Water 112
3 The Suffolk and Essex coast from Felixstowe to Clacton including Orwell and Stour estuaries 87
3 The tidal River Waveney from Ellingham to Breydon Water 87
5 The tidal Deben estuary 86
6 The tidal Rivers Bure, Ant and Thurne 84
7 The Suffolk coast at Southwold 62
8 The north Norfolk coast from Old Hunstanton, to and including Cley 58
9 The north Norfolk coast from East Cley to Kelling Hard, including Salthouse 56
10 The Essex coast from St Peters Flat to and including Shoeburyness and the Crouch and Roach estuaries 47

How can developers and local authorities work on flood prevention and management strategies to mitigate the impact of future flood events?

Local authorities can work on flood mitigation to significantly lower the impact of future flood events through a multifaceted approach.

Flood risk assessment, infrastructure and planning

As environmental specialists, Thomson Environmental Consultants can conduct thorough flood risk assessments and map flood-prone areas, utilising predictive models to identify potential flood threats. This data-driven approach forms the foundation for evidence-based decision-making.

Investments in critical infrastructure, including levees, embankments, and drainage systems, are vital. Local authorities must not only maintain existing defences but also upgrade them to withstand rising sea levels and increased rainfall associated with climate change.

Robust land-use planning is essential to regulate development in flood-prone areas, curbing construction and encouraging sustainable land-use practices. Comprehensive floodplain management reinforces these measures by maintaining natural flood defences like wetlands and restricting unsuitable development in floodplain areas. Zoning regulations can effectively manage risk.

Community engagement

Engaging the community plays a pivotal role in effective flood mitigation. Authorities should raise awareness about flood risks, educate residents on preparedness, and foster a sense of shared responsibility. A well-informed public is more likely to take proactive measures.

Emergency response planning

Local authorities should establish early warning systems, alerting residents in flood-prone areas and providing them with timely information. A variety of communication methods, from flood alerts to sirens, ensure that the public can access vital information in emergencies.

Equally significant, local authorities should engage with emergency services to develop and regularly update plans for flood events. This involves coordinating evacuation plans and resources to manage disaster response efficiently. Collaboration with neighbouring authorities, government agencies, and environmental consultancies and agencies is essential, as it facilitates the pooling of resources and ensures a comprehensive approach to flood prevention and management.

How can Thomson Environmental support you with flood mitigation?

Our team of freshwater specialists have expertise in water resource management, water quality, hydrogeology and hydrology. We offer a range of services, including regulatory assessments, consents, groundwater and surface water monitoring, foul and surface water drainage strategies incorporating Sustainable Drainage Systems (SuDS), SuDS management and maintenance plans and catchment management services.

We can support you in the development and implementation of:

  • Catchment Management
    Key to tackling flooding linked to climate change, catchment-based approaches,nature-based solutions and natural flood management are effective methods for slowing run-off into rivers following intense rainfall and avoiding pollution caused by soil erosion. Examples include wetland habitat creation, land use and land management, including tree planting and low-intensity agriculture practices.
  • Hydrology & Hydrogeology
    We employ scientific and mathematical principles to offer practical water management solutions grounded in precise surface and groundwater data. This can involve optimising water resources for urban expansion, mitigating river flooding and soil erosion, safeguarding against pollution, and conducting flood risk assessments to comply with the National Planning Policy Framework.
  • Sustainable Drainage System (SuDS)
    To aid surface water management our in-house team design SuDS and wetlands, including earthworks and excavation, while also providing strategic advice on pond management, planting, and amenities like paths and viewing platforms, in order to deliver sustainable solutions with both long and short term benefits.

Case Study – Hillingdon Primary School Flood Investigation

We were commissioned by a primary school in the London Borough of Hillingdon following accusations that the school drainage systems were leading to neighbouring residential surface water flooding. We undertook digital mapping and a desk study of site drainage, asset location, topography, geology, soil permeability, groundwater, and Environment Agency flood mapping. We also conducted site visits to establish the site configuration and constraints, including meeting with the complainants and school representatives to establish a current understanding of the issues. We were able to summarise the site’s functioning, alleviate the residents’ concerns about the school’s contribution to the flooding, and make recommendations for the residents to improve the situation. You can find the full case study here. 

Developers and authorities must wisely use natural flood defences and devise flood mitigation strategies that acknowledge the ever-decreasing environmental space due to population growth, prompting the need for adaptive planning.

Get in touch and talk to our experts today about your environmental requirements, and make sure to follow us on social media to keep up to date with our latest news and updates.


Methodology and sources:

We used historic flood alert data provided by the Environment Agency, listing severe flood warnings, flood warnings and flood alerts issued since the flood warning system went live on January 26th 2006, to the present to create a ranking of the highest areas at risk of flooding.

 Our ranking was developed by looking at the total number of flood alerts and warnings listed. The following areas were combined in the data clean-up to enhance clarity:

  • ‘Yorkshire – North and East’ and ‘Yorkshire – South and East’ to create ‘Yorkshire’.
  • ‘Wessex – North’ and ‘Wessex – South’ to create ‘Wessex’.
  • ‘West Midlands – West’ and ‘West Midlands – East’ to create ‘West Midlnds’.

 The Environment Agency data was last updated on 25 September 2023 and currently provides data up to 25th June 2023.

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