The back corner of my yard has always been a problem. My entire 1/4 acre lot is a gentle slope toward the southwestern corner. This coupled with a layer of heavy clay right underneath the topsoil makes for a swamp that only dries out in the dead of summer. Since I have neighbors behind and on both sides I can't dig a ditch to drain it, so I'm contemplating an underground retention basin or dry well to give the water somewhere to go below the surface and then hopefully, slowly dissipate into the ground. Here is what the spot looks like now. Looking south: Looking west-the hole you see is about 2' deep, dug with a hand auger. I wanted to try to get a feel for the soil. After about 8" of topsoil it's nothing but nasty red clay with bits of rock mixed in. I couldn't get any further with the hand digger after 24". As you can also see, my next door neighbor has a 10x10 shed on a slab right in the same area-curiously he has no drainage issue on his side at all. The neighbor directly behind me does, but his property slopes to a drainage ditch along the road in his front yard so at least he has that option. Looking southeast toward the rest of the yard-you can see the change in the grass which corresponds with the level of wetness in the ground. Basically the wet area is where it's perpetually green: As you can see its basically a mudpit. Its impossible to mow (I usually go in there with the weedeater) and its pretty much unusable. The dog loves it of course Anyway, I'd like to reclaim it by eventually putting down a layer of stone and moving the firepit, picnic table, etc...back there, but until the drainage issue is addressed, I can't do anything. Here's the plan: Basically I'm planning on creating a large volume of space underground so that the water can percolate down through the topsoil and a layer of rock, into six barrels. My hope is that the volume will be large enough so that after a good rain the topsoil will be dry, and the water will have drained down into the barrels below, where it can slowly work it's way into the soil. I'd first start by renting a small excavator and digging a pit in the back corner of the yard, about 7' long, by 5' wide, by 5' deep. Once the pit is dug, I'll line the bottom and sides with landscaping fabric. This will keep water from washing dirt into the rock and clogging it. After lining the pit with fabric, a 6" layer of 3/4" washed stone would be spread on the bottom. On top of the stone bed, six 55 gallon polyethylene drums would be placed in two rows of three. The drums would be perforated with 1/4" holes on the tops, bottoms, and sides with the goal being to create as many openings as possible without seriously weakening the drum structurally. Once the drums are placed, the hole will be backfilled with 3/4" washed stone so that the drums are surrounded on the top bottom and sides by a 6" layer of stone. Once 6" of stone is placed on top of the drums, the stone would be covered with landscaping fabric, topsoil, and sod. Here's a crude rendering I came up with: My gut tells me it will work, but I'm putting it out for a sanity check. The one caveat I think of is that I'll have to treat it like a septic tank/field and never drive over it, but I don't usually take the truck back that far in the yard anyway, and as I said, the plan is to make it an outdoor picnic area long term. People around here commonly use poly barrels as drywells for their downspouts, and underground protected from UV rays they should last forever. Thoughts?