It may be the routine, or maybe just the sweltering heat of this Thursday afternoon. In any case, the men from the municipal building yard in Penzberg are a well-established team. Every move is spot on, and so the annual flood protection exercise at the pumping station in Maxkron is quickly carried out. Since July 2006, the system has protected the residential areas in the Maxkron district when the Loisach overflows its banks. The Free State and City of Penzberg had spent 2.8 million euros on the building. The reason: the two flood events in 1999 and 2005 caused considerable damage.
The pumping station in Maxkron looks inconspicuous, but in an emergency it protects many houses that would otherwise be flooded in heavy rain.
(Photo: Harry Wolfsbauer)
The importance of the small house between Loisach and state road 2370 at the end of the town in the direction of Beuerberg cannot be seen. Without this system, however, many houses were still in danger of being flooded in heavy rain. Like in 1999, when this area literally turned into a lake district for days. The problem is not just that the Loisach overflows the dam at a water level of 5.74 meters. In extreme flood events, the water that has accumulated in the meadows along the state road flows back into the Penzberg district. The so-called Binnengraben is then full at some point and poses a danger.
In addition to the pumping station and dams, the flood protection in Maxkron includes a rainwater retention basin with 10,000 cubic meters. The retention areas on the Loisach have the same volume. The highlight is the so-called dam log closure: a barrier across the state road that stops the Loisach water running back. In August 2020, the transverse closure had to be set up because there was a risk of flooding after continuous rain. The system must therefore be serviced regularly so that there are no nasty surprises in an emergency.
Lord of the pumping station is Georg Wagner from the municipal building yard. He himself, his colleagues, employees of the city administration and representatives of the water management office in Weilheim practiced the necessary actions for emergencies. Meanwhile, the Penzberg fire brigade was controlling the traffic: To see whether the stop log closure was functional, it was set up on one side. The men piled up ten aluminum beams. Then another on the second half to check that nothing has warped or jammed. Everything tight, was the conclusion. Meanwhile, trucks, cars and motorcycles had to exercise patience before they could pass the spot again.
Electrician Max Hohenauer checked the functionality of the three pumps at the pumping station.
(Photo: Harry Wolfsbauer)
Wagner explained in detail at which level of the Binnengraben or Loisach the individual alert levels are triggered. There are three pumps in the pumping station, each of which manages a good 1000 liters per second. A maximum of two are in operation. From a water level of 2.63 meters, they start automatically. Should there be a malfunction, the pumps can also be operated manually. An emergency generator is also available. The stop log closure is set at a level of 2.33 meters. This must be done in consultation with the water management office and the district office in Weilheim. Finally, the district authority must set up the diversion notices on the state road. It is then no longer possible for traffic to get through.
At 2.53 meters, the gate is closed to stop the flow of water into the inland ditch. In an emergency, the pumping station is manned by two men who take turns every four hours. Because the service is “sometimes not so gritty at night,” said Wagner. It was a relief that the flood warnings came in via SMS. “But as long as the Loisach is in its normal position, nothing happens,” he continued. Even if the inland ditch would carry plenty of water.