Those ravines sound like a really difficult issue! I can’t imagine - flooding and just pulling more good land down into them.
I love rotten wood, though. I pull it out of the woods and use it as the base for my raised beds. It would cost far too much to fill them, otherwise. I am also trying to reclaim the very steep hillside behind our house. It was clear cut about 10 years ago, and the top 2/3 are terribly eroded. The bottom third grows thick, green grass and wildflowers!
I gathered “used” Christmas trees last year and laid them across the hillside. I’ve been adding Rotten logs, wood chips, leaves, and “used” chicken bedding. I’ve gotten a few flowers to grow in these berms, and I keep adding to them. if we can get the water to linger up on the hill we can get things growing up there and it will look so much better. Last summer we took out almost all the thorny locust that had begun growing up there. Now we just have blackberry brambles.
And my chickens, the darlings, have found spots up in the scrub to lay eggs! They’re locked in until everybody remembers how to use a nest box!