Hey folks, I have a rock retaining wall that is about 7ft tall in my backyard and I plan to install a french drain to keep the water from accumulating behind the wall (on the house side of the wall). My plan is to dig down to the bottom of the wall and install a drain pipe connected to the existing weep holes in the wall and cover it with fabric to keep the dirt out. Then I plan to cover the pipe with 1" to 2" diameter gravel all the way to the surface. I have clay soil and want to make sure the drain does not get clogged. Should I use sand on top of the pipe to help keep out the dirt as well? I have included a photo so you can see what it looks like. Any help or ideas are greatly appreciated. Thanks!