Access to groundwater flood data

For groundwater flooding, we refer to three datasets that are hosted on the Climate Impact Atlas. These include the mean highest groundwater level, the maximum groundwater level, and the probability of excessive groundwater levels dataset. Please find more information about the datasets on the Assumptions & limitations page.

Mean Highest Groundwater Level

mean highest groundwater level
Data owner Deltares, based on outcomes of the National Water Model (the map is hosted on the Climate Impact Atlas)
Data access Mean Highest Groundwater Level
Description The map shows the mean highest groundwater level, based on meteorological data from the period 1911-2010. The mean highest groundwater level is usually reached in winter. This level is often used as the reference groundwater level when planning built-up areas. Constructions are then designed to be able to cope with this groundwater level. More information can be found on the Climate Impact Atlas map narrative.
Available time horizons
  • Current situation
Available climate scenarios Not applicable
Year produced 2025
Spatial resolution 250 x 250 metres
Source documentation Technical documentation

Maximum Highest Groundwater Level

Maximum highest groundwater level
Data owner Deltares, based on outcomes of the National Water Model (the map is hosted on the Climate Impact Atlas)
Data access Maximum Highest Groundwater Level
Description The map displays the maximum highest groundwater level. This is the maximum average of the three highest groundwater levels modelled for a single hydrological year, derived from modelling groundwater levels with the meteorological circumstances that occurred during the period 1911-2010. More information can be found on the Climate Impact Atlas map narrative.
Available time horizons Maps are representative for the conditions during the period 1911-2010.
Available climate scenarios Not applicable
Year produced 2025
Spatial resolution 250 x 250 metres
Source documentation Technical documentation

Probability of excessive groundwater levels

Probability of excessive groundwater levels
Data owner Deltares (the map is hosted on the Climate Impact Atlas)
Data access Probability of excessive groundwater levels
Description The map shows the degree of probability increase of higher groundwater levels between now and 2050. More information can be found on the Climate Impact Atlas map narrative.
Available time horizons
  • 2050 (Note: to view the data, switch the scenario from current to future conditions).
Available climate scenarios

Royal Netherlands Meteorological Institute’s climate scenarios from 2014 (KNMI’14).

Note: since spatial differences in groundwater flood probability is mainly determined by landscape and water system characteristics, the map remains largely unchanged when using KNMI’23 scenarios.
Year produced 2016 (an updated map is expected in 2025).
Spatial resolution 250 x 250 metres
Source documentation

Technical documentation (PDF)