I think the problem of draining the hole from the top is that the shafts are not necessarily straight, vertical, or connected in an obvious way, and you may not just be able to "lower the pump". You might have to pump, go in, find the next shaft or side channel, pump, etc. Not sure how that compares to just draining from the bottom (which in itself may not drain all the various shafts if they are not connected or oriented correctly). At any rate, I agree that it's not a problem that cna't be dealt with, especially once revenue from the "tailings" is flowing.