The times have changed, use to be you would farm the beaver and maintain the populations. Now with so few trappers and an ever exploding population the rules have changed some. Any waters that are connected to a river system I'd catch as may as I wanted. You have a steady supply of replacement animals to fill in the trapped animals. That being said each trapper knows there trapping area and what they can do to manage it. Down here I could catch 100 beaver if I was crazy enough to do it and had the time and I would have no fear of hurting the population.