I'd be interested to see where it came from? Is your next uphill neighbor willing to help YOU out with what he sent your way?
Then, maybe in the conversation with whichever neighbor, or both up and downstream neighbors, maybe over coffee and biscuits at your place, where you could show them what you have at your culvert, you all could form a game plan?
You could if you were to clean the area yourself get a log cone like this one:
Portable Winch Skidding Cone for Logs up to a Diameter of 2 in | SHERRILLtree
and hook it to one of your, or your neighbor's ATV/UTV/Tractors or just a pickup and a section of rope/cable/floss whatever....
But what lands at your door is pretty much on you, what with mother nature and all delivering candy-grams whenever she wants to. As to ethics, ask yourself would I want my uphill neighbor sending stream jammed logs down the hill, for me to deal with?
One can't stop mother nature, but cutting up stuff jammed in your neck of the woods so it will maybe get jammed up downstream, even if the guy is wealthy, (which IS irrelevant), isn't the best policy, and if you wouldn't want it to happen to you, that's the gauge/criteria that most ethical people use to determine what to do in similar situations. Or to put it another way: Crikey!:laughing: