Perhaps the council should devise maintenance plans for bikers.
They can get erosion experts to draw diagrams and give tips on how to build and maintain the sort of tracks we want to ride, and distribute them. This way we can have tracks that people aren't going to bitch about. hundreds and hundreds of people use tracks like ch10, and a lot of them are quite keen to keep them running, and keep them running well. These people underestimate how much initiative MTBers have. We'll dig for hours if it means we get a good track. I've spent the last 5 or so weekends building a kickass dirtjump in my backyard, just for one example.
Surely there are ways of bracing berms, jumps, dropoffs, and any other sort of course obstacle that will limit erosion. Even if we were educated about how we could improve drainage around these areas, and also the most used straight runs, we could cut erosion by an incredible amount.
People seem to forget that keeping the tracks in good nick is in our best interests also. We want to keep our tracks the way they are, not giant barely-ridable dustpits. A few tracks at blackstone spring to mind.
Also, I think some people need to be re-educated about how to brake properly. You see some people riding down these tracks with a huge cloud of dust behind them. Locking up your brakes is not necessary people!
edit:
This is the sort of guideline that should be endorsed and distributed by parks and wildlife, the council, and other major public landowners.
/end rant.