Heavy rain, heat, drought – climate change is accompanied by an increase in extreme weather conditions. Among other things, this puts a strain on sewer systems, which are in need of renovation in many places. The start-up Variokan has responded by developing a variable wastewater system. It consists of a rubber hose that can be drawn into the existing ducts. The key feature is the V-shaped profile in its lower section. This forms a channel for the water to flow through. The advantage: it speeds up the flow, fewer deposits are created – and maintenance costs drop. If the water level rises as a result of rainfall, the profile is compressed, creating more space. An active contribution to flood protection, for the common good.