I have a house that has some real severe drainage issues. Its a 30'x30' area in this persons back yard. The area is filled with extreme clay soils. The neighbor to the one side is about 4'' higher in grade then the property owner I'm working for. The rest are about level. Water always pools at this guys house and sits there for weeks on end. We came in and removed about 7 yards of clay soils while we dug in a french drain. The french drain was dug and made a double, (2 pipes). We then brought in 12 yards of topsoil and graded it out. We didn't't lay sod yet. Last night we got some real heavy rain and water is again standing in the same spots. I'm a little confused on what to do. Maybe more french drains? The current one is 30' in length and 1.25' in width. Any ideas?