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Want to ask input on plan for french drain

I have a fairly serious water drainage problem in my backyard.

The neighbor uphill from me (it's a business complex) has a retaining wall and water has eroded it's way under his wall. This has created a channel where water flows underground a short distance and boils up in my backyard out of a sinkhole. This water boiling out of the sinkhole settles right next to my house, which is clearly bad. I believe it's also the primary reason I have water in my basement.

I plan to regrade the section of the yard near the sinkhole (it's almost perfectly flat, which is not good for drainage) but the volume of water flowing out of the sinkhole is such that it's going to require a drain system.

The water coming out of the sinkhole is fairly silty, so any french drain system would have to be carefully designed in order to resist silt.

My plan is to cut a one foot deep trench through the sinkhole itself, then run the trench downgrade to my drainage swale, and then install a french drain.

I planned to put landscaping fabric in the bottom of the trench. Then lay about 3 inches of 1 inch washed gravel, then lay 4 inch perforated PVC on top of that *that has a filter sock on it*, then lay another 2 or 3 inches of 1 inch washed gravel, fold landscaping fabric over gravel, then backfill the last inch or so with dirt, then sow with grass seed.

I will also be installing at least one cleanout. Maybe more. The perforated section of PVC won't be big, probably only 2 to 3 feet long. After that it will be solid PVC.

Is this design reasonable for a french drain that will have to deal with water that is relatively silty?

Picture time:

You can tell that the water that comes out of that thing is silty. Any drain system I use is going to have to be resistant to it.

Is it a good practice to use both landscape fabric in the trench AND a filter sock on the perforated PVC?

I am also going to regrade the yard as best I can to promote water near the camera to drain into the swale at the other end of the yard. I can probably do it with a roto tiller and a shovel.

I don't want to just rely on yard grading alone, or a surface drain. If water keeps coming from that sinkhole it will continue to erode it, not to mention look awful. I want to drain right out of the sinkhole if I can to mitigate erosion and for aesthetic reasons.

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Iris Design Associates
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Northern Virginia Landscape Architect - 13x Best of Houzz Winner!