I installed a French Drain along my entire back of the house (no drain tile below retaining wall). I wanted to put the flagstone pavers back where they came from, but since I can't put crushed gravel over the french drain, I am not sure how to make them level and solid. I have other places i can use the pavers, so I am not too concerned about keeping them there. In fact, I don't have enough large pavers and have to space them a lot to make it work. I don't want to use pea gravel, but I want it to drain well and still feel solid under foot. Any recommendations?