I've been thinking about building an earth bermed house but am afraid of water seepage through the concrete walls.
An idea came to mind and I am wondering if it has ever been done before and why or why not...

Basically it would be to burry a plastic tarp-like skirt around the perimiter of the house. I figure that this would direct seeping water away from the house, and any that did penetrate through wouldn't be trapped, but instead would be absorbed into mostly dry ground.

I'm attaching a quick picture to help explain.
Any thoughts?

1. Build your walls with ICFs.
2. Waterproof with peel and stick waterproofing such as Miradri.
3. Install dimpleboard drainage plane such as Miradrain or Delta.
4. Install 4" perforated drainage tile to daylight.
5. Backfill with clean wash rock to within one foot of finished grade.
6. Sleep peacefully in your dry home.

Ooopie

Lstiburek shows a similar approach in "Structural Insulated Panels (SIPs) for all climates."  P. 142 and fig. 6.15, p. 143.  Only he kept it 12" deep rather than angling deeply as you show, and he only went out 6-10 feet with both the surface and plastic on a sloping away from the house. 

The book's modestly expensive, but there is a LOT of information in it; look at the Building Science Corp. web site.

Very respectfully,
Larry

What they said. All I can add is our last house on the "deep" side was about 28 feet down to the basement floor. We made darn sure there was good drainage, we went with a 4 inch perforated with silt sock and a second 4 inch perforated without silt sock. One contractor said one was better so I put them both in. I figured for $100 extra it was worth it to be sure. Then we covered that with clean washed rock, about 4 feet worth (that was the expensive part). The side of the exterior cement was tarred and then 2 inches of foam. The two 4 inch lines wrapped around the house and met at the low side, only 12 feet down. Then it connected to a 6 inch line that ran about 100 feet slightly down hill until it was out of the ground. We never had an issue with water in the house and the required sump pit was dry as a bone. We did initially have radon problems being so deep but once we covered the sump pit and a couple other small openings we were good to go. We also had water running out of that 6 inch line all year round, melting a huge path out in winter. In the spring I bet we have 40 gallons a minute running out of it.

Look into using bentonite or hydroclay panels. These can be attached to the outside wall before backfilling, (or pumped into the ground if grading has been done). Once in place the carrier will disintergrate leaving the bentonite. As an all natural product it will stay flexible and self-healing. The National Institue of Science recommends it as a green method of waterproofing and it acts as a barrier against gases such as radon. I would stay away from any plastic barrier. Using solid poly to try to keep water out is a recipe for disaster. The plastic usually ruptures in one spot creating a funnel channeling all the water to that hole and ultimately into the structure.