The following is a description of the latest operational release of EFAS v5.0. For an overview of other EFAS releases, please see: EFAS versioning system.


EFAS v5.0 introduces a number of major changes to the system, including:

  • a higher spatial resolution. EFAS v5.0 has 1 arcmin/ 0.0166667 degrees resolution (~1.4km), as opposed to all the previous EFAS versions having 5-km resolution.
  • a different project system, now based on EPSG4326 instead of ETRS89 Lambert Azimuthal Equal Area Coordinate Reference System (ETRS-LAEA) for previous versions.
  • a larger modelling domain whose extension has been enlarged to match the river catchments. 
  • an entirely new set of 0.0166667 degrees resolution input maps produced using the most recent research findings, remote sensing, and in-situ datasets.
  • major improvements to the open-source hydrological model LISFLOOD.
  • a new calibration at 1903 in-situ gauging stations, with a parameter regionalisation performed to estimate the parameters of catchments for which in situ discharge observations were not available.
  • new return period thresholds and snow water/soil moisture anomaly maps based on a climatology from 1992 – 2022. The EFAS v5.0 river discharge climatology is available at the C3S Climate Data Store.
  • updated hydrological post-processing models, recalibrated for EFAS v5.0.
  • new flood hazard maps, generated using LISFLOOD-FP at 90m resolution and MERIT hydro DM and EFAS v5.0 reference dataset
  • new reforecast configuration (medium-range), with the hydrological reforecast datasets being generated during the operational processing chain
  • ERIC based on LISFLOOD surface runoff outputs instead of empirical relationships
  • ERIC notification points and reporting points shown only for catchments below 1000km2
  • additional flood event information available in the Rapid Impact Assessment pop-out table (see EFAS Rapid Flood Mapping and Rapid Impact Assessment)
  • updated exposure information used in Rapid Impact Assessment (see CEMS-Flood flood impact forecasting)
  • an updated major rivers layer (see Static Layers Overview)
  • new rules for defining dynamic reporting points (see EFAS v5.0 - Dynamic Reporting Points)

This upgrade of EFAS has large impacts on the EFAS modelling results.

Other smaller changes include the adjustment of the temperature evolution graph in the reporting point window, which was corrected to show the average temperature of the whole catchment.

EFAS v5.0 Evaluation Results

Technical details

Pre-release date (available on stage platform)


Release date2023-09-20
In test suite


EFAS internal number

Archiving of data


Reference climatology (for thresholds/ anomalies)1992-01-01 to 2022-12-31
EFAS Historical1992-01-01 to near present


Horizontal projectionEPSG4326
Horizontal resolution0.01667 x 0.01667°
Temporal resolution6-hourly

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