5m UK and Republic of Ireland Flood Map

Since 1998, the UK has experienced seven of the ten wettest years on record. An estimated five million households, or one in five, are at risk to flooding in the UK, with annual damages from flood estimated between £500 million and £1 billion each year, and over 45,000 homes are at risk to flood in Ireland.

This is likely to increase under a changing climate. Comprehensive flood data is therefore key to managing the risk both now and in the future. 

As a result, over 12 years since we first released our data, we remain committed to the continued development of our 5m UK and Ireland Flood Map. Now in its tenth generation, our mapping was the first to offer national coverage for all major flood types at 5m resolution, empowering the re/insurance, financial, NGO, charitable and public sectors in their flood risk assessment and management. 

2020 update

We offer an annual update to our mapping and, in response to client feedback and new data availability, the 2020 release includes updates to the river (fluvial), surface water (pluvial) and coastal layers, as well as updates and new additions to the Defended Areas layer to demonstrate the mitigating effects of flood defences when present.

2020’s update is the culmination of three years of significant updates to our coastal mapping, with complete remapping of England and Wales coastlines taking place since 2018. This has included remodelling of astronomical tides, storm surge and wave overtopping with new methods and data, as well as updates to the dedicated defended coastal layer to demonstrate the impact of flood defences on resulting risk.

The JBA team has also included new high-resolution Lidar data and, where required, our specialists have meticulously reviewed and cleaned terrain data, including over 100,000 edits to digital terrain models, for improved definition of river channels, narrow urban streets, infrastructure and terrain, and a more realistic representation of flow paths and flood extents.

To ensure our mapping represents flooding most effectively, we have also updated our UK and Ireland flood maps based on observed flooding during recent events, including areas that were affected by flooding in November 2019 and February 2020. This includes updates to river and surface water layers in Yorkshire and Lancashire, as well as major populated towns and cities in these areas previously affected by floods.

Furthermore, we have updated river and surface water mapping in Cornwall, Devon and the south-west of Ireland, including Cork, as well as included additional flood defence schemes in Scotland.

Comprehensive flood modelling

Our flood data can be used by re/insurers, mortgage providers, banks, asset managers and other investment organisations to effectively assess the extent and severity of flooding, for improved decision-making across risk selection, underwriting, pricing, portfolio optimisation and funding and investment opportunities. The data can also be used by public bodies for land use planning, disaster preparedness and more.

We use bespoke methods for each flood type to account for their unique hydrological characteristics, with an option to view each flood type separately or in combination for a more comprehensive insight into which flood type may be the driver of losses and what the potential claims costs may be.

Our mapping captures all major rivers and smaller streams in the UK and Ireland at high-resolution 5m grids – key for a highly localised peril where one property might be flooded and the neighbour spared – and specific modelling is undertaken for the Thames Estuary to understand a worse-case scenario on the Thames river and surrounding areas. This high-resolution approach allows for more competitive pricing through better differentiation between properties at risk for the major flood types.

The mapping is complemented by our Defended Areas datasets, delineating areas that may be protected by defences despite being flooded in our maps, to enable clients to make business decisions according to their own risk appetite by incorporating all, some or none of the defences in their risk assessment.

The mapping is accompanied by a range of associated data, including simple flood risk scores and colour-coded flood ratings at property level, as well our financial metrics at both location and portfolio level from our Pricing Data and UK probabilistic flood model.

The mapping can also be used alongside our range of climate change data to understand potential changes in flood risk across the UK.

We're committed to ensuring our clients can access our data in a way that suits them. For easy integration into existing systems, our UK Flood Map is platform agnostic and available:

  • In-house directly from JBA
  • Via our wide range of resellers
  • As part of a JBA consultancy service to help identify exposure hotspots, run per-risk flood assessments and manage accumulations.

For more information on any of our UK data, please get in touch. We also have 5m flood maps available for the US and Continental Europe, as well as 30m flood mapping globally.

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Flood Services

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Event Response

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