Cross-border flood portal:
www.hochwasserzentralen.de

A joint initiative by the federal states has launched the Flood Portal. Here, water levels can now be displayed, along with situation reports and river basins.

My flood map: 
https://flood.firetree.net/

My Flood Maps provides a global map where users can observe the impact of a water rise of up to 60 meters on land areas.

Flood Atlas BKG Germany: 
https://atlas.bkg.bund.de/webapps/hochwasseratlas/ 

The Flood Atlas of the Federal Agency for Cartography and Geodesy offers an interactive web application to visualize flood information. The application also includes a location search and rainfall forecasts.

Flood visualization:
http://www.hochwasserrisiko.giub.unibe.ch/3D_Visualisierung/

Visualization examples of flood events from the University of Bern.

European Flood Awareness System:
https://www.efas.eu/de

The aim of EFAS is to support preparatory measures before major flood events strike, particularly in the large trans-national river basins and throughout Europe in general. EFAS is the first operational European system monitoring and forecasting floods across Europe. It provides complementary, added-value information (e.g. probabilistic, medium range flood forecasts, flash flood indicators or impact forecasts) to the relevant national and regional authorities. Furthermore, EFAS keeps the Emergency Response Coordination Centre (ERCC) informed about ongoing and possibly upcoming flood events across Europe. Since 2012 EFAS is running fully operational as part of the Copernicus EMS. 

Flood Hub von Google:
Flood Hub Map

Google’s Flood Hub provides flood forecasts through AI models up to 7 days in advance. It analyzes local river water levels and possible flooding areas. This allows citizens, emergency services, and authorities to be warned in time, minimizing damage. More information can be found here.

Global Flood Awareness System (GloFAS):
https://www.globalfloods.eu/

The Global Flood Awareness System (GloFAS) is a component of the Copernicus Emergency Management Service (CEMS). It was developed to support flood preparedness globally, particularly in large transnational river basins. To provide information on ongoing and upcoming flood events, GloFAS combines satellite data, models, and in-situ measurements.

Inondations Luxemburg:
https://www.inondations.lu/

The Flood Forecasting Center Luxembourg provides measured water levels and flood forecasts for major watercourses in Luxembourg. When the alert service is on standby, the pages are supplemented with current flood information and flood situation reports. The reports contain weather data, discharge conditions, and water level forecasts for reporting gauges.

PEGELONLINE - Hydrological Data Portal:
https://www.pegelonline.wsv.de/gast/start 

PEGELONLINE offers free access to daily raw data of various hydrological parameters (e.g., water level) from inland and coastal gauges along federal waterways, available for viewing and downloading up to 30 days retrospectively. Additionally, PEGELONLINE provides data via eight different web services. PEGELONLINE was awarded first place in the Open Data competition in 2012, category Data (www.apps4deutschland.de).

Heavy rain information maps NRW Germany:
https://geoportal.de/Info/tk_04-starkregengefahrenhinweise-nrw

The heavy rain hazard indicators show simulation results of heavy rain events in NRW, with maximum water levels and flow velocities for rare and extreme events. These can be used as a basis for detailed analysis. The data was calculated using a 3D model and additional geodata.

Flash flood hazard maps Rhineland-Palatinate:
https://wasserportal.rlp-umwelt.de/auskunftssysteme/sturzflutgefahrenkarten

As air temperatures continue to rise, summer local heavy rainfall events are becoming more likely in Germany. Heavy rainfall, i.e., exceptionally high rainfall over a short period, can occur anywhere, as these events are not terrain-dependent. The State Office for the Environment (LfU) has conducted landscape analyses, the results of which are compiled in a Flood Risk Analysis After Heavy Rain map.

Heavy rain hazard map of the BKG:
https://www.bkg.bund.de/SharedDocs/Pressemitteilungen/BKG/DE/PM_2021/211028-Starkregen.html

The Federal Agency for Cartography and Geodesy (BKG) has released an interactive map with heavy rain hazard indicators for North Rhine-Westphalia (NRW), showing results from heavy rain simulations for this area. The map includes data on maximum water levels and maximum flow velocities for rare (100-year) and extreme events (hN = 90 mm/m²/h) and can be accessed through the federal and state geoportal. BKG President Professor Paul Becker emphasizes the need for a unified map for all of Germany.

Damage potential surface runoff: 
http://hochwasserrisiko.giub.unibe.ch/Schadenpotenzial_OFA/de/

Surface runoff, especially during heavy rainfall, poses a significant and often underestimated risk. Although at least 50% of flood damage is caused by surface runoff, few Swiss cantons have prescribed protection measures against it. Therefore, the Mobiliar Lab for Natural Risks at the University of Bern conducted an analysis of the damage potential due to surface runoff in Switzerland. This analysis evaluates damage potential at the municipal level, taking particularly vulnerable buildings into account to minimize overall flood risks. The results also emphasize the importance of considering surface runoff in urban planning. Detailed data for individual municipalities can be downloaded in Excel format.

WMS Heavy rain hazard information North Rhine-Westphalia:
https://gdz.bkg.bund.de/index.php/default/open-data/wms-starkregengefahrenhinweiskarten-nrw-wms-starkregen.html

The representation service for heavy rain hazard indicators presents the results of heavy rain simulations for the North Rhine-Westphalia (NRW) area. The data includes the maximum water levels and maximum flow velocities for rare and extreme events.

Heavy rain App:
https://www.starkregenalarm.de/

The heavy rain early warning system detects local and small-scale heavy rainfall in your municipality. By providing early warnings to citizens, emergency services, and authorities, damage can be prevented, and in extreme cases, lives can be saved.