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
| Data owner | Deltares, based on outcomes of the National Water Model (the map is hosted on the Climate Impact Atlas) |
|---|---|
| Data repository | 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 |
| Available climate scenarios | Not applicable |
| Year produced | 2025 |
| Spatial resolution | 250 x 250 metres |
| Source documentation | Technical documentation |
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 repository | 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
| Data owner | Deltares (the map is hosted on the Climate Impact Atlas) |
|---|---|
| Data repository | 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 |
|
| 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 |
