Short reminder, based on an experience about 40 years ago. Schutzie had built a frame for his experimental cataraft; a 20' monster intended to haul massive loads long distances in heavy whitewater. An ill thought out decision to make a quick test run on the South Platte to test the new frame took place just above the inflatable dam that formed the cooling intake for a Public Service plant on the South Platte River. Promptly upon launching Schutzie could tell that design and material changes would be called for, but pressed on, looking forward to sliding over the inflatable dam to "test" other elements of the new frame.
The test did not go well. That is to say the test accomplished what was intended, mainly to uncover any weaknesses in design or materials, but it did so spectacularly.
On dropping over the edge the frame suffered a significant failure of materials caused by stupid design, poor material selection, chancy construction and a pesky side wave that emphasized just how critical frame rigidity and strength is when a cataraft is in the mix.
In any case, the frame failed, the tubes separated, Schutzie and his bride ended up in the water, and a first rate lesson in hydraulics took place.
As it turns out, water flowing over a low head inflatable dam will recirculate at the base of said dam, trapping debris, incautious rafters (yes even when said rafters are wearing a life jacket) raft debris and the bodies of animals, notably dogs.
After being pummeled in the recirculating water for several minutes, which included being dragged down the face of the dam, Schutzie determined that drowning was in fact a possibility. His bride had already arrived at that conclusion, and during one brief moment when both were circulated to the surface announced "You've killed me you bastard!" Schutzies denials were literally washed from his mouth as they started yet another trip down the face of the dam.
Moments later Schutzie determined, entirely by accident, that in fact one could stand up in the maelstrom although footing was somewhat uncertain. Dragging his bride to the surface and asking her to "stand up dam it!" proved to end the immediate danger, that is until the body of a dog washed up between them.
Schutzies bride promptly expressed her sorrow at the demise of the animal (EWW!! GROSS!! EEEEEKKK!!) and abandoned her mate by heading downstream. Schutzie, recognizing that nothing more could be done for the animal, followed suit.
Recovery of the tubes and shattered frame followed quickly and Schutzie and his bride headed for the showers. Several showers.
The tubes were much later sold to an unsuspecting guide headed for the Grand Canyon, where reports showed that a more stout frame based on a better design resulted in exactly what Schutzie had been aiming for; a 20' monster intended to haul massive loads long distances in heavy whitewater. Schutzie's visionary ideas coupled with a more reliable frame probably led to the acceptance of catarafts as a raft type, early failures notwithstanding.
In any case, the moral of the story is; beware of low head dams, whether a chute exists or not; the things are known to prefer rafter meat and will sneak up and BITE YOU IN THE A$$. In particular the one christened dead dog dam on the South Platte