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Hi all,

A boundary retaining wall we have is seeping water in a couple of places at the very bottom only after a downpour. This lasts for days and will eventually dry up with enough time but the water pools near the wall as can be seen in the pic. From what I can tell, the wall is part of a soak-away system and is approximately 30yrs old. It's a double leaf wall? block/concrete internally with Stone on both sides and pilasters along the construction. Should I be concerned or is there anything I can do to remedy this?




1 Answer 1


You should be concerned a bit. During the heavy rains the wall is supporting both the pressure of the saturated heavy backfill and hydrostatic watter pressure at the same time.

Repairs can be costly. You need to install sump pits or just pits filled with gravel every few feet on the back of the retaining wall and allow them to drain through pipes across the wall.

You can investigate around your neighborhood and see what are the doing and if it has solved the issue for them. If there is an accepted method it means you can find skilled people who can do it.

  • $\begingroup$ It might have been designed to retain the water pressure - why would you be concerned then? If it has been standing for 30 years and nothing has changed (e.g. haven't raised the height of fill behind it) I wouldn't be concerned. $\endgroup$
    – achrn
    Aug 19, 2020 at 7:09
  • $\begingroup$ Yeah it’s been standing for the last 30 years and there are no signs of leaning/buckling so structurally I think it’s fine. But the pooling of water from the bottom is starting to tell me that the drainage system in place behind the wall isn’t containing the water as it should and somehow water is getting past this in various spots. Funnily enough, the spots mentioned also have large foliage growing from the backfill. Could the root systems have penetrated the drainage system? Or disrupted it? $\endgroup$
    – DerekOS
    Aug 21, 2020 at 18:44
  • $\begingroup$ if you have low temperatures during rainy season icing could have caused cracks and created pathways fo leaking. $\endgroup$
    – kamran
    Aug 21, 2020 at 18:52
  • $\begingroup$ I live in south Ireland, generally pretty mild in terms of temps, rarely have more than a couple of days at or below freezing. Since the mortar is missing from the bottom in spots, would there be any issue if I was to fill these back in with mortar? or am I looking at excavating completely behind the wall & redoing the drainage, backfill? $\endgroup$
    – DerekOS
    Aug 21, 2020 at 19:39

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