In July 2021, large areas in Western Europe were hit by extreme rainfall. For example, in the Geul catchment, maximum precipitation amounts of up to 180 mm were recorded. The Waterboard of Limburg estimated that the damage was around 1.8 billion euros in the Netherlands, while the total international damage is more than tenfold that amount. The thematic working group Limburg 2021 of the Delta Futures Lab in Delft works on a variety of research topics to add to the knowledge about the event and to investigate how such large damages can be avoided in case of future events. These investigations include topics on flood risk management, climate change, flood damage estimates, hydrological assessments of several areas, and a comparison of the effects of this flood to the effects of historic events.