Not far away, another shorter route was built from the river to the sea in 1940. That flume was built in concrete elements, which unfortunately was less suitable than wood due to its inherent high friction. Congestions and log jams were very frequent.

I spent a fair amount of time to find some parts of this concrete flume, but it was apparently completely eradicated shortly after the flotation ended in 1970. However, at a particular location, I found this dump of concrete elements. The profile seems to match what I've seen on old pictures from this flume.