Residents could also be warned by local SMS service
“It was already clear in the afternoon that the water was increasing. At 6:45 p.m., the flood could be seen coming,” reports the mayor. The first site of the operation was a private cellar that had to be pumped out, and then the situation escalated significantly in the next 30 minutes, says Braun.
The municipality has set up its own warning service via SMS for such extreme storms. This is voluntary, so people are warned about upcoming storms and asked to take the necessary precautionary measures.
Braun: The shaft at the market square is a “needle eye”
Kastl is a municipality with 40 districts and some mountainous areas, but the market square is in the valley. According to the mayor, 23 square kilometers of the municipal area drains into the Lauterach at the market square. Experience has shown that the water runs off quickly over the mountainous areas and then flows into the adjacent river via the market square.
The shaft on the market square, through which the community’s water would flow into the Lauterach, was a “bottleneck,” said Braun. However, there is no technical solution that would completely prevent flooding: “There are no such pipelines” that can withstand so much rain, explains Braun.
The police reported around 20 operations throughout the Upper Palatinate. The fire brigade in particular was called out because of fallen trees, flooded streets and flooded cellars, said a police spokesman.
As much rain as normal in the entire month of May
Around 80 litres per square metre were recorded in Kastl yesterday evening, says BR weather expert Christian Lorenz. “Normally, 60 to 80 litres fall in the whole month of May,” says the meteorologist. So it rained as much in one night as it normally does in an entire month. That’s why you could call this an event that normally occurs about once every hundred years, says Lorenz.
“Hard hit”: One thunderstorm cell followed the next
But how could such severe flooding have occurred? The problem in Kastl in particular was that the town was hit directly, and no meadows or fields could have absorbed the heavy rainfall. Kastl was “hit full on” because one thunderstorm cell was followed immediately by the next. This “long band” of storms brought massive amounts of rain with it.
Are storms of a similar nature now threatening?
“Today, possible showers and thunderstorms can be expected to be a little heavier in places,” says Christian Lorenz, around 10 to 20 liters per square meter. “Today the situation is not so dramatic, from tomorrow afternoon and on Friday night it will become more critical again,” explains the BR meteorologist.
On Thursday, a low from Switzerland and the Lake Constance region would bring large amounts of rain to southern Bavaria. In Swabia and Upper Bavaria in particular, long-lasting, sometimes thundery rains with amounts of between 10 and 40 liters per square meter within six hours can be expected, says Lorenz. “Then there can be occasional floods and full basements or something similar,” warns Lorenz.
With information from dpa