Wuppertal – storm water flooding

The SUDPLAN pilot of Wuppertal will develop planning tools for dimensioning of water runoff systems and other infrastructure solutions to mitigate the effects of storm water flooding.

The SUDPLAN Scenario Management System (SMS) will provide planners in the city of Wuppertal a system to run multiple simulations of heavy stormwater events and determine the corresponding run-off in the sewage system and on the surface.

The system will help to assess both the damages that may be caused by flooding and the effectiveness of different planning options, thus providing decision support to the planners. Moreover the SMS will enable to visualize the results in advanced 2D-, 3D- and 4D-representations – a foundation for discussions with the concerned property owners.

Heavy rainfalls block sewage system

The city of Wuppertal, a town with approximately 350,000 residents, is the biggest town in Germany that is situated in a hilly landscape. It is located in the steep, narrow and long valley of the Wupper river. There are several creeks on both sides of this valley that open into the stormwater sewage system before they finally end in the Wupper.

wuppertal
The steep narrov valley makes the city of Wuppertal very vulnerable to storm water flooding.

During a heavy rainfall event the city’s stormwater sewage system is quickly blocked by those swollen creeks, causing the precipitation to run off on the surface. This stormwater run-off often damages valuable public infrastructure and private property. To make the situation even worse climate change is considered to have an increasing impact on the frequency of heavy stormwater events in Wuppertal.

Hence the city managers have decided to integrate the modeling of surface run-off after heavy rainfall events in the long-term planning process of the stormwater sewage system. To achieve this a hydro dynamical model should be used to detect the critical spots on the surface, where a high risk of flooding encounters valuable and vulnerable facilities.

But knowing these critical spots is not enough: the overall target is to mitigate the risk of flooding. To find appropriate measures for that it is necessary to consider climate change, to be effective in the long run. And – with respect to the ever growing financial constraints of the city – the suggested structural measures should not only be effective but also cost-efficient.

The installation of a mobile wall or the heightening of some road kerbs is, for example, certainly less expensive than the construction of a retention basin. Naturally the responsible planners are in need of a powerful software tool to get all this modeling work done.