In his video (nice job Brian!) Brian stated that the area he was standing was permeable. Actually, is a water collection area that is on the roof of several underground rooms. You can see it in the photo above. That area then directs water that flows off the roof into the underground infiltration system, a large perforated underground tank. That tank then overflows, if necessary, into the rain garden, or the green infiltration area. It is pretty well explained in the diagram, and seems to be working well. – Harry Carnes
Advertisement
