The site had been cleared of all trees and bushes so we could start excavating and laying out the base (Check out how we did this here.) There was a lot of earth to move so a skid steer was rented for a long weekend of fun. It was worth every penny in the time and energy it saved. If we had to dig it by hand we would still be digging. The utility company had already been contacted and they gave us the all-clear for digging. The initial soil was mainly black dirt but once we dug deeper we found mostly sand. It is important to not build your wall on top of black dirt because it consists of mostly organic material. Organic material will decompose and your wall will settle. The excavated soil was carefully piled in the most out of the way location in the yard. We will use this soil at the very end of the project as either backfill or top soil for planting and having it out of the way was important for site management.
The shape of the wall was laid out using a 100 ft (30.5 m) garden hose paying close attention to our desired symmetrical shape along the back property line. We learned the garden hose trick on allanblock.com. My wife and I worked together on the layout so when we finally hit on the right set of curves, we painted the edges for the trench to guide us when digging.