Urban Water Agenda

Bonn

Why an Urban Water Agenda 2030?

"A major part of the current problems of environmental policy cannot be considered at the local level alone. Water is essential for life on our planet. Our ecosystems, society and economy all need clean fresh water in sufficient amounts to thrive.  As a city located at the banks of the river Rhine we take full responsibility to protect the ecological system. We know that our effluents of sewage treatment plants will become drinking water downstream of the Rhine. The quality of water does not stop at the city borders. The City of Bonn is quite advanced when it comes to water protection, but we know that there are still things to do. On the one side, we want to have a strong role in the development of European water policies and on the other side we like to share our best practice. We support the goals to become a sustainable and resilient city."       

Helmut Wiesner, Executive Director of Municipal Planning, Environmental Affairs, Traffic and Transportation of the City of Bonn.

Bonn at work | Early warning system for torrential flooding

Bad Godesberg and Mehlem are two neighborhoods in the southern part of Bonn traversed by what normally are rather small creeks. However, heavy rainfalls in summer, which should not occur more often than once in a hundred years, led to disastrous flooding in the creeks' watersheds  in 2010, 2013 and 2016. There was no warning in advance so the people of  Bad Godesberg and Mehlem were caught fully unaware by the torrential runoff. Fortunately, there were no casualties.

In late 2016, the Department of Civil Engineering of the City of Bonn decided to explore technical options to send an early warning to potentially affected residents in case the neighborhoods are again affected by heavy flooding. The creeks were equipped with four measuring sites each, where the water level is checked every few minutes. Critical levels have been designated for each site. In case of rising levels above these specific values, an alarm will be sent to the municipal Fire Department. Video cameras transmit live video footage to put the department in the position to warn the civilian population by siren, radio announcement or smartphone-based apps. Depending on the storm cell's exact local position in the watershed, the time between detecting the rising water levels and the flood wave's arrival in town varies from 90 minutes in the best case to barely 15 minutes at worst. However, this is still enough time to stack sandbags or at least - and most importantly - to reach a safe place.

The devices for measuring water levels have been installed outside the flood-affected regions on the creeks' banks. They are radar-operated and work totally contactless to prevent them from being destroyed during a flood by driftwood, debris or the water itself. The devices are battery powered, with the batteries being charged by solar cells. This independence from the power grid is very important as there is a high risk of a power cut during heavy thunderstorms, which cause these floodings in summer. The system is operational since July 2017 and is working smoothly so far.

Interested in finding out more? Contact the Head of the Office, Peter Esch (e-mail: Peter.Esch[at]bonn.de).

One of the sites fitted with sensors to measure water levels, as described in the text

Bonn's  member of the UWA2030 Core Group

Heinrich Thiemann (Team leader  engineering  municipal wastewater treatment plants.)

Heinrich Thiemann has more than 30 years of experience in the subject area of wastewater.

 

Quick facts on Bonn

Location within country

The Federal City of Bonn is a city on the banks of the Rhine River in the German state of North Rhine-Westphalia. About 24 km south-southeast of Cologne. Bonn is in the southernmost part of the Rhine-Ruhr region - Germany's largest metropolitan area - with over 11 million inhabitants

Number of inhabitants

324,670 (2017)

Main economic sectors

The headquarters of Deutsche Post DHL and Deutsche Telekom, both DAX-listed corporations, are in Bonn.
The city is home to the University of Bonn and a total of 19 United Nations institutions.

Source/s of water supply

Barrage water

Main utilities providing water and waste water services

The drinking water in the distribution network comes from the Wahnbachtalsperrenverband (WTV), the largest water supplier in the region. The association operates three water extraction plants:
- the  drinking water reservoir Wahnbachtalsperre
- the ground waterworks Hennefer Siegbogen
- the ground waterworks Meindorf
The Federal City of Bonn also runs four wastewater treatment plants.

More information: www.bonn.de

Updated: September 2017