JBA 5m GB Flood Map provides vector flood extents and banded depths for river, surface water, coastal and groundwater (chalk areas) flood sources. The data is presented at 5m resolution for a range of return periods (annual exceedance probabilities) from 1-in-20 to 1-in-1,000 for defended and undefended scenarios in Great Britain. Data for Northern Ireland is also available on request.

JBA 5m GB Flood Map is created from simulated rainfall-runoff processes and the JBA 'J-Flow' hydraulic modelling software, which simulates flood inundation across large areas. The simulations consider how water flows across a digital elevation model taking into account land cover data and is based on approaches from the Flood Estimation Handbook (the national standard for flood estimation in the UK). TUFLOW kis used for coastal storm/surge modelling.

JBA 5m GB Flood Map is intended for customers to make informed decisions about flood hazard in their area of interest. The flood extent and banded-depth information provides a visual representation of flood hazard and helps in various applications, including:

- Insurance - to understand the likelihood of flood damage in specific areas
- Urban Planning - to identify areas where flood defences are required or where mitigation/resilience measures should be implemented (e.g., raising buildings, improving drainage).
- Emergency Response Planning to identify potential evacuation routes and understand where resources might be needed most during a flood event.

JBA Flood Map for Northern Ireland on request. Updated annually.