30cm to 90cm in five months is brutal. The spot I worked in Red Rock had the same problem, a side-by-side trail ran right along the edge of our unit and one monsoon season took out a whole wall. What really burns me is the runoff part. Once that channel cuts in, it keeps cutting every rain, so you are not just re-recording depths once, you are chasing a moving target all season. I would flag the new channel line on your site map now and shoot GPS points on both banks, because next spring those will have moved again and you will want the before and after. Get the ORV damage documented with your state historic preservation office too, some of them keep track of repeat routes and can push for a gate or barrier. Two feet of lost dirt is a lot of context gone, sorry you are stuck with the paperwork.

two seconds" is about right, isn't it? A guy who has done it a thousand times can spot sloppy work from across the hangar. My question is about the lead. Did he walk you through the why on each rule, like why the fixed tie spacing means a longer service life and not just a neater look, or did he mostly show you the how? I ask because I had a guy once who told me to change a method but never said why, and I nodded and went right back to my old way the second he was gone. It only stuck when someone took the time to explain the reason behind it.