Problem with the waterfall

After some tests I have discovered that the waterfall will not work as I had hoped.
The water does not fall in a nice stream in front of the wall.
It will either form a single thin stream or curve back and flow down the wall.
Luckily this can be fixed by removing the gap between the water and the wall.
Sadly this means that I have to get rid of the track as this will disrupt the water.
Back later with ideas.