The city council is paying 200,000 Euro for the early warning system. As reported, the gauges constantly measure the water lever of the streams. A sensor, placed in what looks like an oversized arm, measures the water level by radar. At the same time, a camera near the stream transmits live pictures during torrential rainfalls, also in darkness thanks to infrared spotlights. „A solar panel delivers the energy for the system“, explained Esch, whose staff members Hans-Jürgen Hauser und Barbara Frielingsdorf were the masterminds behind the system.

The data gets transmitted to the traffic computer which is normally in charge of the traffic lights. But how will the information chain at the new facility at the Marienforster Steinweg work? According to the head of the department, the first alarm level is reached if the water rises to more than 52 centimeters, at the moment it is only at a level of twelve centimeters. „If the system records a level of 79 centimeters, it raises the alarm with the Bonn fire brigade, who in turn sounds the alarm“, said Esch. Thanks to the computer network, the control room in the Rhein-Sieg-Kreis is informed and in turn passes the signal on to to the Wachtberger fire brigade.

Should the water level at the Marienforster Steinweg rise dramatically, the water needs only 17 minutes to reach the Godesberg city centre - last partially flooded on June 4, 2016, during a storm. From Villip on, where another facility will be installed, it would be about an hour. Residents would have some time to take precautionary measures. Esch explains the sounds of the sirens, which are different to the ones of other emergency situations, because of rising and again ebbing tones: „If the sirens sound, the people of Mehlem know, thanks to former torrential rain falls, that they have to place their prepared sandbags.“

In Bad Godesberg he sees an urgency to protect people from „high water dementia“, from forgetting what can happen, only because it is more seldomly occurring in their area. In general he urges people to get themselves to safety once the sirens sound. „If you are a resident near the stream and you are in the cellar of your house, the fast rising waters can be life threatening.“ The prototype at the Bachemer Straße stirred up some interest outside of Bonn already. „The Rhein-Sieg-Kreis is interested in the system“, said Esch. Also, a delegation from South Korea was enthralled, because it seems to be the first system of its kind. The city council has not yet patented the alarm system.

But because they developed it together with a software company, they would have the necessary know-how. And soon also eligible data. „We have to now watch our theoretical measurements in practice“, said Esch. If necessary, there might be adjustments. Despite the innovations there is never a hundred per cent protection from torrential rain falls: „Just like during earthquakes“, said the department manager.

(Original text: Silke Elbern; Translation: Mareike Graepel)