I thought I'd post a few picts of before, during, and after my pool going in. My yard had a ~25 foot grade difference from the back of the house to the back of the property. I had to build almost 1000 sq ft of Versa Lok retaining walls to make it all work. The back retaining wall is 5 feet high at the highest point, had to be engineered, and the use of Geogrid cloth to tie it into the hill was needed to hold the wall. We hauled out over 400 yards of dirt and rock to get the grades correct and then use walls to make it all work.