2 years ago I installed a perimeter drain on the wet side of my house. It daylights at the road and works great. Last week, I installed an additional 30' leg. The new leg is inboard of the existing drain and runs parallel between it and the house. Construction is identical to the old drain: good pitch, lined w/ non-woven cloth, perf (holes on the bottom), #2 stone over top, then wrapped like a burrito and secured w/ landscape staples. It wasn't practical to daylight this leg at the road so it terminates into a catch basin. The basin connects to the existing drain. There have been several significant rains since install and no water flows. Zero. I'm stumped; it should be working. It's worth noting that the soil spread on top was wet so it is compacted. Water isn't infiltrating as well as I'd like, but the soil layer also isn't very deep.

  • Does the original drain have crushed rock up to the surface? Why did you place a new drain inboard of the first one? Was water standing between the first drain and the foundation? Nov 13, 2021 at 21:36
  • Jim, yes; there was standing water between the existing drain and the foundation. It is not an "open" french drain--meaning the stone does not come to the surface. A shallow layer of (wet) topsoil was placed over the #2. (Shallow = ~3".)
    – Francis314
    Nov 14, 2021 at 1:13
  • To clarify, the new drain is not open (it's covered w/ topsoil.) The existing drain is open--#2 finishes the drain at grade.
    – Francis314
    Nov 14, 2021 at 1:27
  • Presumably there is a swale parallel to these two drains and parallel to the foundation. Where is it located relative to the foundation and to these two drains? Nov 14, 2021 at 1:51

2 Answers 2


On many soils, rain will only penetrate an inch or so.

So if you have a good layer of soil then you have effectively waterproofed your drain.

I put one in using a trench alongside a gravel path and as it had the same stones no one knew - worked well though.


Assuming everything is built correctly, water is simply not rising to the level of this drain. Possibly because the level is adequately controlled by flowing sideways into the existing drain, or it's otherwise happy to keep flowing down below the drain level (or across the surface) rather than accumulating and flowing into this pipe.

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