I was hoping someone here might be able to help me make a plan for the retaining-wall my husband and I are building.

We've had drainage issues since we moved into this house. The back yard slopes down toward the house and our basement has flooded several times. We just had it waterproofed last year and now we're trying to divert water away from it so as not to challenge the new waterproofing system any more than we must.

We're dealing with plenty of water. When they installed a new sump-pump they also had to put in a new outflow. It was making my back-yard and side yard a soggy mess so I dug a meandering stream bed for it to follow and installed a fountain. That helped, but the slope was still aimed right toward the house. So we started the process of excavating to create a slope away from the house last week.

As you can see, everything now slopes toward the bottom right side of the picture above and we've trenched it all the way to a nice sized hole in the ground (as my darling assistants demonstrate) where we hope the water from the downspout above, as well as any water that drains away from the house will end up:

You can see the slope of the yard that we're dealing with in this picture. We'll obviously have to back fill a lot so we don't end up just building a waterfall. I think the retaining wall will end up about 4 ft tall, maybe up to 5 at the deepest point.

I was thinking of doing something like this (photo of a book page--I can't remember which one I found it in, though.):

So, to get to my question. Obviously we'll be dealing with a bit more than the usual amount of water-pressure on this retaining wall. Even though it'll be dry-stacked I want to put a heavy-duty drainage pipe behind and slightly below it. I know there are perforated pvc pipes that can withstand 1000 lbs of pressure, but they're rigid and straight. I don't want to use the flexible stuff because I'm positive it would be crushed by the heavy stones. Is there a way to use the perforated PVC to make it follow a curve? Could I join pieces together with connectors that aren't perforated and have it all work okay? What would you recommend?

Thanks for any help!

Alina

We've used (non-perforated) flexible pipe for other applications and it doesn't seem all that tough. I'd hate to put so much effort and expense into something that won't hold up for at least my lifetime. But I guess it might be my only option? Although, I think a crushed/damaged drainage pipe would be worse than no pipe at all in this scenario.

Min3, that's not a bad idea. Thanks for the suggestion.

I'm surprised more people haven't run into this issue. Maybe I'm over-thinking it? I guess if I'm careful, the flexible pipe is probably the best option, but I saw many warnings against it in my reading. What do the professionals who don't like flexible pipe using if they're building to a curve? Hmmm...

Thats the route I would go. Your dry creek bed seems like a good idea and should help a lot. Best of luck.

An 18" garden wall is no big deal. You're talking about a four or even five foot wall? That's nothing to screw around with, especially since the goal is serious water diversion from a basement that's already had water intrusion issues. I can't recommend strongly enough the involvement of a professional.

I realized the drainage goes behind the wall, marcinde. Behind and slightly lower (so "below") is what I thought, am I right? I'll look up the anchor-retaining walls, thanks for the tip.

I appreciate the time you each took to respond, thanks!