Have a look at the rubble trench in detail later. There are some shots in the “building” drop down as well. There is a 4″ drain in the trench draining to daylight, which also happens to be next door? Anyway, we have had severe rain since installation and it took care of it very well.
You can use this plan section to loft out the bag row heights and radii if you wish. In general the bags are tamped 6″ deep anyway and the corbel is about 3″ a row as a double check. The radius compass worked very well for this. We later filled the bags a lot heavier and got about 8″ thick.