Heavy downpours swamp Germany: Flood alerts for numerous regions
As torrential rain continues, Germany braces for flooding in numerous areas. The German Weather Service (DWD) issued a flood warning on Christmas Eve, cautioning of potential inundation on various rivers and streams across the country. The relentless precipitation is set to persist until Monday, particularly affecting the north-western and western slopes of many low mountain ranges. Up to 150 liters of rain per square meter may fall in these regions within 48 to 96 hours, with even more precipitation possible in certain spots, according to the DWD in Offenbach. The impending thaw, such as in Erzgebirge, is further heightening the flood risk.
Lower Saxony on High Alert
In Lower Saxony, many water gauges reached the third of four warning levels, as stated by the State Agency for Water Management, Coastal Defence, and Nature Conservation. Rivers like the Weser, Aller, Leine, and Oker, among others, surpassed this threshold. At level three, the risk of property flooding, large-scale inundations, and damage to roads and cellars increases.
The Hanover fire department was in constant operation due to the heavy rain and high winds, reporting significant water damage in buildings and tree removal efforts.
In Rodenberg, located in the Schaumburg district of Lower Saxony, fire departments and volunteers deployed sandbags in an attempt to shield vulnerable areas. According to Mayor Thomas Wolf of the joint municipality, the floodwater had already breached the weir by Sunday morning. Helpers had visited homes to warn the residents, as this level of flooding had not been experienced in the area for 25 years.
Widespread Warnings
The flood forecasting center in Saxony-Anhalt issued alerts for the Mulde, Aller, and Havel rivers. Alert levels 1 and 2 were surpassed at several measuring points throughout the state, with level 3 also reached at several locations in Saxony – such as in Chemnitz.
Authorities in North Rhine-Westphalia prepared for potential flooding. Concerns arose in Oberhausen due to a softened dyke on the Ruhr, as reported by the fire department. On Saturday, the fire department in a Münster suburb rescued a woman from her submerged car, which was stranded in a flooded area of the Werse, a tributary of the Ems.
Flood Alerts in Bavaria
Some districts in Bavaria have been placed under a level 3 flood warning, with other areas falling under a level 4 warning. Notable inclusions are the districts of Coburg and Kulmbach. Flooded cellars and closed roads have resulted from the precipitation, and some areas had already experienced flooding by Sunday night. To further complicate matters, a woman had to be rescued by the Bavarian fire department after her car became stuck in a blocked Flooded road on Saturday in Near Heustreu, the Rhön-Grabfeld district.
Strong winds hampered skiing in parts of Bavaria on Christmas Eve. The Bayerische Zugspitzbahn needed to halt cable car operations to Germany's highest mountain due to an "out of service" notice. A lift on the Zugspitzplatt was also inoperable on Sunday. However, the cog railroad to the Zugspitze, which was not functioning on Saturday, was operating on this day.
Avalanche Conditions and Impact on Alps
An avalanche commission had to evaluate the situation before reopening the pistes on the Alpspitze near Garmisch-Partenkirchen. Significant avalanche danger persisted above 1500 meters on Sunday.
Enrichment Insights
Heavy rainfall events often result in natural disasters like floods, gravitational mass movements, and tree falls. In 2021, extreme rainfall and high water levels in the Ahr valley led to a catastrophic flood. The floodwaters caused significant damage and resulted in 190 fatalities in what remains one of the deadliest floods in recent German history.
Almost every part of the German rail network has experienced disruptions due to heavy-rainfall events since 2011. The risk of flood and tree fall events is substantially increased by such events. However, gravitational mass movements have not been significantly impacted in this context [1].
Local authorities have been warned to consider the effectiveness of their early warning systems and evacuation efforts in light of recent flooding. The drawbacks of underestimating the inundation area and inadequate early warnings were critical in the 2021 Ahr valley flood.
[1] GIS analyses and random-effects logistic models were used to illustrate the impact of heavy-rainfall events on the German rail network. The route and topography were vital considerations when assessing the susceptibility of various railways to associated flooding and gravitational mass movements. In regions with valleys or low mountain ranges, railway services are particularly vulnerable [2].
