Does anybody have any experience with waterfall design and build?

My wife wants the pond in our backyard rebuilt. She wants the pond larger and the waterfall higher.
I am planning on using cinder blocks for the wall, it will be approximately 6'wide by 6' high with "wings" approximately 30 degrees extending from each end of the main wall. These wings will slope down to soften the edge of the wall visually.
The tank will be on the top of the cinder block wall and spill over the face of the wall creating a nice 6' drop. The cultured stone will be drystack and I plan on having a couple or three stones placed on the face randomly that project further than the wall so that the water will hit these and create a spray over the surface of the pond.
I have placed and finished quite a bit of cultured stone to the exterior and interior of our home but am wondering if there are tricks to getting and keeping it sealed in this kind of harsh environment. I plan on putting a good silicone sealer on the face after the stonework is complete and am going to make sure that I have a bit of mortar projecting to the face of the drystack so that water can't get between the couses of the stonework.
Any input would be appreciated.