# excavating in front of a retaining wall



## rdwyer (May 26, 2020)

Hello all.

I have a question about digging in front fo a retaining wall without loosening the footing of the wall.

I have a Versa Lock patio retaining wall (blocks are 6" H x 16" W x 12" D) that are pinned and back filled with river bed stone and a drain. I built it probably 5 years ago and it's solid and hasn't moved an inch.

I want to construct a water feature that will mimic a stream bed dumping water over the lip of the wall across a section perhaps 5' in width. The wall is 42" in height across this section. The water will empty into small Koi pond/water garden at its base…likely cascading against some New England field stone and into the pond. I expect the pond to be about 10 feet wide…following the base of the wall and extending out perhaps 8 feet and 40" deep.

My question is how do I excavate in front of the retaining wall without weakening the wall footing? The footing is currently 3 courses of block (18" buried) on a packed stone dust pad. Furthermore, if I do excavate as described, would it be best to build a reinforced rebar and cinder block wall to serve as the backside of the water garden up against and below the retaining wall footer?

Thanks for any info.

-Rick


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## hsvtoolfool (Jul 23, 2018)

I think your idea is very cool, but I would not dig closer than 2 or 3 feet to the wall base, or behind the wall within 2 or 3 feet. A lot depends your soil type and the back fill. Talk to an engineer. Better safe than sorry.

Given the size of the pond and the wall height, my advice is to drop the idea of using the retaining wall itself as a waterfall.

If you want a man-made art-piece look, I would build a sculptural water feature right up against the wall. Everything should be on top of the ground, in front of the wall, and removable without affecting the wall....



Personally, I prefer a natural "rock spill" built against the wall. The rocks would be stacked above ground for at least 3 feet from the wall. The waterfall would cascade down natural rocks. It would be really cool if a few medium-size boulders were sliced in half to create the illusion they were actually part of the retaining wall. The large rocks actually helps anchor the wall...



Finally, if you decide to build a small pool above the wall, I'd use a small above-ground basin surrounded by rocks and landscaping rather than dig into the wall backfill. I'd also run the plumbing behind the wall far from the retaining wall as possible (and dig shallow as possible).

Good luck!


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## rdwyer (May 26, 2020)

thanks for the feedback. no digging behind the wall except to create the stream bed of the water cascading down to the fall itself. As far as the look, i'm intending to use new england field stone and I'm considering dismantling a good portion of the wall to have some of the larger boulders actually create the cascading fall. Then reassemble the wall around those boulders to really give it a look as if the stones were always there and I built a retaining wall around them.

If I do dismantle the wall infront of where I want to put the pond/basin, I would think I could then dig with less of an impact on the wall footings.


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