[SoCalSurf]

I'm redoing my back yard and it will sit lower than my neighbors. The existing ground is extremely poor for draining so I'm planning on installing a french drain (with pvc pipe) around the perimeter. I'm also building a cinderblock planter around the perimeter. Please look at the attached diagram as I'm not exactly sure where to place the drain for maximum effectivity. Any thoughts or comments are greatly appreciated. Thanks!

[Lanelle]

If you are receiving surface water draining on to your property, you're going to want to catch the water before it has a chance to undermine the footer closest to the fence. Consider putting a channel drain along the fence line, moving your planter in to make room for it. If you have sub-surface water issues, then your french drain placement may help some.

[jshilan]

First of all, and most importantly - does your property have to be below your neighbors property? Can you build up your grade and / or patio so water runs away from your house but does not build up around the perimeter of the property (without forcing you to build up the grade on the house itself).

Next, the walls seem like they are just going to "dam" the water even more, and depending on where you live, can actually push the water back up towards the house, or even into it if the weather is severe enough.

If your grade is truly lower than all of the surrounding properties you need to not only "catch" the water but run it into a seepage tank or recharge tank. If this is the case, I would divert the water away from the planter walls (just like the house) and try to grade the property so the water goes to a more centrally located catch basin that then runs into a seepage tank.

Water management is really pretty easy. Water runs down hill and always seeks its level. 90% of the drainage problems I run into are either due to improper grading or some self inflicted situation like building a berm or other obstruction directly in the way of the natural flow of water.

If you can, shoot a few spot elevations to see what is really going on elevation-wise and then rethink the design before you potentially make things worse.

If you can post some pictures, I'm sure you can get some other solutions too.

[SoCalSurf]

First off, thank you so much for the replies!!!!!

I've attached a property overview drawing. (My camera is on the fritz). The blue dotted lines on the side represent a french drain (with pvc) and the property slopes to the sidewalk where I have holes drilled for the water to drain into the street. I've done some elevation checks and as long as I install my drain properly I'll have no water flow issues. The patio will have a slight slope away from the house and away from the inner planter wall and will have drains.

1. Yes the water would seem to damn up against the outer wall. I have no other choice since it abuts the fenceline. I can't dig into the neighbors property.

2. I could pull the wall in 4 inches and put in a channel drain but that would be awkward with the space between the wall and the fence.

3. I can't build up the grade without having a wierdly sloping patio. This is one of the reasons for the planter walls in that it keeps the dirt below the normal fenceline off my patio.

Also, if anyone is in Southern California I'd be willing to pay for help on this design phase.

Thanks again!

[jshilan]

Hey, I thought it doesn't rain in Southern California so there's nothing to worry about.

From your drawing it looks like there is some sort of drainage easement between the two properties specifically for this situation. In NJ, we normally pitch our patios from 1/8" per foot to 1/4" per foot for runoff. This keeps the water from sitting on the patio and the olives in the martini don't sit to one side.

I agree that it is worth meeting with a contractor or landscape architect, or engineer to discuss a solution that may well be more cost effective.

Good luck with it and please keep us posted.

[Raj Venugopal]

Instead of doing a stone patio like it looks like on your plan, have you thought of laying clean drain rock in the area closest to your house (say 20 feet or so) and doing an elevated wooden patio? That way you could position some french drains underneath as well. I'd be afraid of doing any hardscaping in an area that is lower than someone elses, drainage or not. Then, assuming that your lot slopes to the rearyard at some acceptable pitch, you could lay your stonework. (hope I explained that right).

[Raj Venugopal]

a lot of what I wrote may not apply. I just saw your thumbnail.

[agla]

If the water drains from the neighboring property onto yours, your wall will block that from happening. That is a big no-no. It might not cause a problem, but if it does you would be responsible for it. It is really not a good idea.

[Mau]

I had a similar situation here in So. Cal. a couple years ago. The adjoining property was 3' higher - level with the raised planter on 'my' side which was 3' above the rest of the yard. When I dug a hole in the yard I found the water table 6" down. The guys who had just done the hardscape had cut the old drain that ran to the street and laid a new one - that was just under the new sidewalk but above the high water table. So I couldn't use that drain, I had to route a drain to the other side of the property and run out to the street from there.

jshilan, you're right, it doesn't rain in So. California. Last year we had 2.5 inches for the entire year! But people here make up for it by irrigating like there's no tomorrow.

You wouldn't believe how many people I see that don't know how to set their sprinkler timer. Many, if not most, run it for 5 - 10 min a day, 12 months a year. Their lawns are saturated to the point that moss is growing. Proper timing around here would be something like 3 times a week for 12 - 15 min. during the 4 Summer months, 2 times a week for Spring and Fall and once a week in the Winter.

The 4 houses that sat above this property all watered too much and it migrated down to this one.

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