This is what I think a french drain is? Someone can correct me if I am wrong. You basically have some kind of pipe either inside your house below the basement floor, or outside the house buried under gravel, soil, and sod. It moves the water from downspouts and/or water flowing under your foundation out a pipe away from the house. You either have a pump to push the water out or gravity. They are supposed to put some kind of mesh material between the gravel layers if outside to keep the drain pipe from getting clogged. But being under so much pressure, tree roots, and time will cause it to be clogged. I think if you were to do a great install you would set up access ports along the pipe so you could go in and clean a clog if necessary. Otherwise you have to rip out everything.