I have a bid for a residential homeowner who has a drainage problem. Theres a hill thirty feet back from the back of their house and at that crease water sits and puddles. The puddle area is about two hundred feet long across the entire back yard. Theres three inch cor. and perf. drain pipe right in the middle that has failed, think there's no gravel under it and it's clogged. How deep should I dig to make a bed for gravel and the pipe, how wide should that bed be? Should I continue to use the perforated pipe? Do I use fabric between the pipe and gravel, or on top of them both? should I bury the pipe in gravel? How many inches of gravel underneath? The goal is to drain all that water away from the back and theres good grade on both sides of the house to move that water. I just need to know how to lay the pipe? Also how much would be a good estimate for this job? I figure I'll hand trench, the soil is clay/silt, there's one big elm tree near pipe (ten foot) that has roots for pipe to sit on. Mostly this is just trenching and installing pipe, aprox two hundred foot long. One chainlink (four foot) fence section will have to be removed and reinstalled. The pipe can drain on both sides of the house I'll need to figure out how much gravel I'll need, how much dirt to haul, (same cubic foot), and how much time to trench, install the gravel and materials, and relay the sod. What demensions should I use for the trench, how deep, wide times two hundred foot long approx.