This threat is exacerbated by the fact that the river passes through Zürich Hauptbahnhof station in a tunnel that limits the river's flow capacity, raising concerns about the capacity of the tunnel to deal with extreme flood events.
This threat is exacerbated by the fact that the river passes through Zürich Hauptbahnhof station in a tunnel that comprises 5 culverts with a length of and a clear opening of by each. This limits the river's flow capacity, raising concerns about the capacity of the tunnel to deal with extreme flood events.