As we see here, it is possible to float and walk over the aquaduct. It must be quite a thrill paddling along that side as the drop down was pretty scary. A guide was taking this group over and I would think he had given many warnings and instructions of how to behave here, especially no standing up or trying to pull oneself up onto the edge. Even for the walkers, when passing other people one had to be careful you did not fall into the canal.
The PiP shows telephoto view from this side, at the start/finish of the aqueduct with the much more usual narrow canal boat crossing.


Best full screen

Enjoy the day