There's a creek on some family land that has an artesian spring in it and I've always wanted to make a swimming hole out of it. The creek bank is probably 20' in places and the water at the bottom is a small trickle. I'd like to build a small damn and create a swimming hole. The kicker is that a ton of water moves through the creek after rains, hence the 20' deep sides. Is there anyway to damn it up in such a way that it won't wash out when the creek floods and won't fill up with silt? Has anybody on the all knowing OB tried something similar?