Non‐Conventional Solution for River Mouth Design

Abstract

Conditions at the mouth of the Reuss River into the Lake of Lucerne (Switzerland) were considerably altered first by intensive river training works and then by dredging. The resultant shore erosion can be halted, and the original situation reestablished by recreating a natural river delta. The feasibility of this project was proven by model testing. In particular, it was possible to show that the basic concept was not only ecologically desirable but also technically sound by investigating the periodic scour and deposition patterns characteristic of a river mouth. The delta zone is separated from surrounding land by small flood dykes and a sill in the river channel which prevents backward erosion. The delta can thus be left to natural evolution processes. A plan for the first developments to realize the project was evaluated from the model tests.