I looked at such things for power generation. I have a friend just above a weir so had fast water over it's edge and a drop. It wouldn't work though, which is why boats have wind and solar.
It's not fit and forget. The youtube one works but his water is so fast it's producing 6" of foam. Listen to it. It's shallow water feeding it which acts like a filter. What does come it kinda climbs over he says. His design is strong unlike the guttering version which guides sticks in between the gutters and barrel. Strong as it is, he uses cheap line for when it breaks free. In a river lots of things come down. Just last week a neighbour found a full plant against the bow. Buds and all. Everything comes down there. Logs. Branches. Boats. We have a stream that regularly floods. It drains some arable land. It seems impossible the amount of sticks that get in it.
I don't think the barrel with it's little gutters would do anything in a river. What you need is a free energy device. The kind of energy that will keep you there all summer working on such a project. If nobody hear it.
I had wondered about floating debris as well, because there is a fair amount of flotsam that gets carried along with the current in my river. I did notice a couple of youtube videos where a loose fence of sticks was stuck in the river bed just upstream from the floating pump, to catch or deflect any larger floating debris, away from the pump.
As the dry season bit harder here, and my obsession with finding a low maintenance irrigation method took hold, I did in fact order a submersible pump, solar panels, charge controller, relay, and even an AA battery-powered water pipe stop-valve timer.
But then, while awaiting that slow boat from China, I got to wondering about how I would be able to conceal all that pricey equipment from prying eyes and light fingers, and that is what started me down this new rabbit hole of seeking a cheap, disposable water pumping system that I could stand to lose in a worst case scenario.
I may in the end try to install both the solar powered submersible pump, and this floating barrel spiral pump, plumbed into the same supply line leading to my grow site, using non-return (check-valves), to prevent the water flowing in the wrong direction.
I recall a few years ago in this forum when Back Country used to post elaborate irrigation schematics illustrated with colorful diagrams, and I remember thinking he was being obsessive about his inventions, but now, thanks to global warming, I'm just as preoccupied as Back Country was, devising innovative and wacky irrigation ideas which may, or may not work in the field.