I've a 10M long retaining wall as shown in the diagram. I've added weep holes every 1M at the bottom (basically missed the mortar in gaps) and then covered with a little DPM and 10mm gravel. I intended to use 32mm waste drain tubes every 1M above the soil level on the opposing side but I'm wondering if this is even needed, that is how is water going to back up in the gravel enough to warrant it? I suppose it could do if there's enough to overwhelm the weep holes?

