I'm Lucy, and I'd be happy to answer your questions today.
The city may be able to come out and fine your neighbor for the illegal height to the property. However, if he's creating a danger of your property flooding as a result of his changes, then you have the ability to file a lawsuit for nuisance. A nuisance is when someone interferes with someone else's use and enjoyment of their property. The judge can order him to put the land back the way it was before and pay you for any damage that occurs to your property before it's fixed.
Dumping dirt on your property is a trespass. A judge can order him to pay the costs of removing the dirt AND order him to pay punitive damages in an amount high enough that he'll think twice before doing this again.
If you'd prefer to avoid going to court, a local attorney may be able to help send a demand letter to see if you can work things out without a lawsuit. A local attorney can also help you prepare a Complaint if you decide to sue. These types of cases are usually brought in a land court, if your area has one, or a district court, rather than Small Claims. A law library in your area should have books that show what a Complaint might look like, if you prefer to draft it yourself (most courts won't have forms for this type of thing).
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