Waterfall over existing rock: need to waterproof?
I have a naturally occuring 6-ft limestone "cliff" next to my patio behind my house. This is where probably the house builders excavated out the hillside to install a slab for the house.
I would like to build a waterfall there, letting the water run over the existing rock. Assuming it is solid rock, do I still need to waterproof the rock so water will not sink into it and escape into the ground bemeath the rock?
Of course I could jackhammer into the rock, lay down a flexible liner, then cover it again with rock, but this would defeat the purpose of using the existing natural cliff.
BTW, I live in Central Texas, where the limestone is very near to the surface and the soil layer is shallow. At the top of the "cliff" there is some soil, which I would need to dig out and cover with a flexible liner and rocks. This would be for the upper 2 or 3 feet of the waterfal, before the water gets to the existing solid rock.