Landlord Question and Answer Forum

We own rental property in a neighborhood that is set up to drain storm water down the street. My property is on the low side of the street where yards and driveways have berms to keep the water from coming into our property. We recently had a tenant turn over and it was discovered that our yard has experienced extensive flooding over the last few years that has washed out the dirt under a large section of our foundation (which you can't see until you look under a concrete walkway where the dirt has also washed out). Our tenant never informed us that the yard was flooding. It turns out that this was caused by the neighbors tenant parking in the yard between the houses (our yard) which flattened the land grade and killed the vegetation that held the dirt in place. This allowed huge amounts of water that ran down the street to run straight into our yard. The cost to fill the void to prevent structural damage to our rental is $3700 plus ¿the expense of building a new concrete berm. I am wondering what responsibility the neighbor's tenant or their landlord has in this situation and would their homeowners insurance help cover this expense. Any advise?