All the drains are run correctly buddy. The pipe you see in the first set of pics is a down spout that runs out, under the walk and then into a drywell. Any other 4" pipes you see are just sleeves to pull irrigation and lighting wires through. Honestly this is one patio I could of built with no wall drains. The main patio is sitting on 7' of clean stone. This was a over dig situation. We brought in 1600 tons of stone for this project.