GeeDub,
Rocky-T and I were discussing this some time ago right after my excavator finished our project. The subject focus was the front perimeter of the building site pad we built up. My contractor put the slope at 3:1 from where the pad ends, continuing at the same grade below the water line, all the way to the bottom. I told him I wanted the 3:1; my instruction, right or wrong. Rockytopper suggested that I seriously consider re-grading the slope above the waterline, knocking it down to ease maintenance. His words are wise. When I confronted my contractor on the phone with the idea, he waved me off.
This page of the Bottomscaping Thread picks up my post with my contractor's explanation.
Your diagram of High/Low pool made me think of it.
