You can put anything you want to in a timber contract, if the buyer has a problem with your request he can either agree to abide or you can contract with someone else. If your waterways have limbs and crap in them that interfere with the water drainage and they won't clean it up then call the Alabama Forestry Commission. Same thing with the trash and 5 gallon buckets, if they leave them and won't clean it up then call the Alabama Forestry Commission.