Flood protection and revitalization of the Kleine Emme

In August 2005, the canton of Lucerne was hit by widespread flooding. The catchment area of the Kleine Emme was particularly affected. Damage to buildings amounted to over 200 million francs. With the flood protection project, the canton of Lucerne is ensuring that the population and infrastructure along the watercourse are better protected against flooding in future, while at the same time improving the ecological value of the Kleine Emme.

In the Stägmättli section near Malters, the channel was widened to the so-called regime width. This creates the necessary discharge capacity and restores the natural morphology of the river. Two new concepts were used in the process. These include bank breaks in the form of "saw teeth". These stimulate the dynamic widening of the Kleine Emme instead of mechanically widening the channel cross-section. Over time, the watercourse will shape the river itself and widen it step by step. In addition, various deadwood structures and so-called "engineered log jams" were created in the bed and at the foot of the embankment. These bed and bank structures provide valuable aquatic habitats, especially for fish. The natural erosion banks in the area of the sawtooths are a delight for kingfishers, among others.

The hydraulic engineering experts from Basler & Hofmann were in charge of the construction and planning project as part of an engineering consortium. The Stägmättli section near Malters is one of two sections to date that the team has also worked on and supervised during implementation.