It looks like we're going to have to spend what we budgeted on a waterfall on excavation instead, d/t rock. All of the poolside waterfalls I've seen have been constructed of rebar and gunite, but is it possible to use actual rock instead? Would a landscaper (as opposed to a PB) be able to do this? I'm wondering if we can put all these beautiful granite boulders we'll be paying a fortune to get out of the ground to good use...