Re: Retaining Wall Responsibility
I am not a lawyer or a surveyor. The following is only conjecture and has no basis in law or case.
If I am reading the original post correctly, there is currently no retaining wall; just a constructed embankment to provide for the neighbor's driveway.
Since it appears that the embankment was constructed for the purpose of the neighbor's driveway, the neighbor is responsible for the embankment. Your neighbor's responsibility to you is to ensure that the embankment does not impact your property. You may receive some benefit from a retaining wall, but the benefit is that your neighbor's dirt doesn't end up on your property: if your neighbor didn't construct a road, you would receive no benefit from the wall. Therefore, your benefit is indirect and solely comes from your neighbor's actions.
To the extent that the neighbor's embankment construction encroached on your property, regardless of when the construction happened, the owner of your property at the time should have granted easement for that encroachment. Lacking that easement, you have no responsibility; in fact your neighbor has a responsibility to restore your land to pre-construction condition. In the event that there is an easement, your responsibility is limited to ensuring that the easement is not encumbered. That is, you cannot willfully damage the neighbor's construction within the easement.
Effectively, providing that failure of the embankment is through no cause of your own, the entire responsibility for the embankment is your neighbor's.
I think you are being very generous and a good neighbor. If any portion of the retaining wall ends up being on your property, have a lawyer write up an easement granting your neighbor use of your land for the wall. Ensure that the responsibility for the maintenance of the wall is clearly defined.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.