Trying to see why others would do/ have to say. Plans are to build a 2nd tier deck, a few steps down, that will step down from middle of deck and eliminating the long/steep stairs. Then where the pool used to be (was there and gone from previous owner) build a patio. My concern is drainage. When it rains a lot that area and along the front of the shed flood towards the low spot near the fence. Just on the other side of the fence looks to be a drain/sewer line. Not sure how well it actually works but when it rains heavy that whole area is flooded. I do plan on ripping up the exposed French drain and redoing that. My thought was to also run another French drain from below where he patio would be to where the water drains towards the fence?