Waterproofing a retaining wall?

[yossarian19]

The back of my carport (where I actually do all the automotive work) is a retaining wall, 2' high, made of landscape blocks with no mortar. Naturally, the property to the rear of the carport drains downslope through my place.
With the rain we've had this winter, the carport is turning darn-near to a pond.

I'm thinking about pulling the wall out, digging deeper, and rebuilding the wall with cinder blocks and some mystery process to make the new retaining wall waterproof. I want / need a dry floor in there.

I've also considered a perforated PVC tube or half-round, mostly burried along the wall, to guide surface water away from the wall.

I might also just add ~3 or 4 yards of gravel to the carport to raise the floor. I dont' care if water is down there as long as I'm not on my back in it.

So, I'll assume I don't actually know WTF I'm talking about here. School me, please?

 

[ADSR]

Delta ms with drain rock will solve your problem.

 

[DougWil]

You can remove the wall, put in a real retaining wall and footing and put drain rock on the backside with drainpipe to a lower location away from the carport.

This kind of setup, on the left.

Or dig a trench in front of the existing wall if you have room and drainpipe and drain rock to a lower location.

A waterproof wall will simply divert the water around and under it and probably right in your carport.
Plus all that soggy soil water weight (hydrostatic pressure) will help overturn or tilt your new retaining wall.

 

[TonkaJoe]

You can remove the wall, put in a real retaining wall and footing and put drain rock on the backside with drainpipe to a lower location away from the carport.

This kind of setup, on the left.

Or dig a trench in front of the existing wall if you have room and drainpipe and drain rock to a lower location.

A waterproof wall will simply divert the water around and under it and probably right in your carport.
Plus all that soggy soil water weight (hydrostatic pressure) will help overturn or tilt your new retaining wall.

^^^ This right here is similar to what I would have suggested myself

 

[yossarian19]

OK, from what I am seeing here and reading elsewhere it looks like building up the gravel bed another 4" or so is probably the answer. The water only pools in a handful of low points. The rest of the carport isn't dry exactly by workable.
It would be a long winded explanation but trenching in a french drain sounds like a bigger project than I can manage right now. Topography of the site, free time, etc.

 

[DougWil]

Sounds like your carport doesn't have a concrete floor?

What about your house?
Is water flooding, ponding around it too?
If so, that is something to be very concerned about.

 

[rvieceli]

In addition to what has been already suggested, You might want to take a look at also trying to divert the surface drainage away from the wall. It won't cure the problem but it will help.

It could be just a ditch in the area before it gets to the wall to catch and direct the water away from the wall.

 

[Cyberbear]

You seem to be dealing with a lot of variables, and a long term permanent solution is presently not in the budget for this project. If you are still considering tearing out the existing retaining wall and replacing it with cinder block, I'm presuming that a footing and re-bar will be used as well, otherwise it's the same as the no mortar blocks you have.
Perhaps adding a drain line at the base of the retaining wall, a plastic water barrier behind the cinder block, and a surface drain channel at the top of the wall is a consideration. Any way you choose is going to require an amount of labor and materials no matter which solution is tried. Or simply lay down plastic sheeting when working in the carport. JMHO

 

[yossarian19]

Yep - carport has a gravel floor.
The house & the garage stay dry without any issues.
I get puddles of water in low spots, where a tire has torn up the gravel a bit etc, but not what you'd call lakes or foundation-threatening stuff (carport is an extended roofline from garage)
Cyberbear nailed it - lots of junk going on at the building site, not enough cash, going to do what I can with a few yards of gravel and see how it goes. Wife and I have decided that we just aren't going to spend a ton of money making our starter home our dream house. In five or ten years, we may well be in another state.
Thanks for the advice, I'm going to price out a couple options and see what I can do.