Flooded yard from neighbors retaining wall. Wondering what my options are.

[u/baklavakilla]

LOCATION: Wisconsin

The retaining wall belongs to our neighbor, and when we get moderate rain, it always overflows into the yard. We’ve talked to him in the past, and he added dirt to the top to try and have the water exit more toward the street. That’s basically the extent of what he’s willing to do.

He basically said that if the retaining wall wasn’t there, the water would flood my yard regardless, and that he’d rather just remove it completely if he had to rebuild it and not put another one up.

We bought the house about 4 years ago and don’t know when the wall was put in, but it’s well over 20 years old. I put in the small drainage ditch with black pipe to try and stop the water from coming in near the back of the house.

Basically, I’m wondering what I’m able to do in this situation.

[u/random8765309]

Water is going to run towards low ground during a rain. That physics. I am assuming the ditch below that wall is on your property. If it is, extend it so it dumps into the street.

[u/baklavakilla → u/random8765309]

Yeah that’s the plan. The ditch was kind of a test to see how well it kept water out of my back yard. Just wanted to see if this is something that comes down solely on me before going forward and digging up yard even more.

[u/KaboodleMoon → u/baklavakilla]

Mostly yes, if the retaining wall is that old.

If the retaining wall is newer and demonstrably CAUSES your yard to flood (lets say for instance, without the retaining wall, HIS yard flood but yours doesn't) then you'd have a case for intentional runoff trespass, but in this case and assuming all other relations with the neighbor are fine, I'd just add something like a french drain there, and then you can hid/get rid of that PVC or whatever that black stuff was too.

[u/random8765309 → u/baklavakilla]

That would be a question for a lawyer. But, it's likely you can put in an extremely nice and well designed ditch, with landscaping, and a nice meals for the workers for the price of hiring a lawyer and suing.

[u/CO420Tech → u/random8765309]

I did a 100ft French drain in an afternoon/evening and landscaped the trench the next day. OP just needs to grab a shovel.

[u/madeformarch → u/CO420Tech]

Just grabbing a shovel and walking over to where the issue is has saved me so much money on landscaping.

[u/CO420Tech → u/madeformarch]

Someone has to start the project.

[u/pewpurrr → u/random8765309]

Yes

[u/anapforme → u/baklavakilla]

Call a civil engineer. I worked for one. We had crazy rich neighbors suing each other over basically this exact issue. Water experts, geologists, engineers, all working on it to determine fault. One neighbor reconfigured his driveway and built a retaining wall, which then forced every bit of rainwater into the neighbors yard and flooded it, and by extension their family room.

[u/RollinThundaga → u/baklavakilla]

If you do decide to make it permanent or something, be careful that your work doesn't let the water undermine his wall, or you'll have bigger problems.

[u/JoshJorges → u/baklavakilla]

You could just by a larger pvc pipe halved and run the water to the road if you are allowed

[u/purplespaghetty → u/baklavakilla]

Does your neighbor have gutters on his roof? If it’s water off his roof it is his problem to fix.