You weren't worried about your neighbor's landscaping, but then you noticed that they were making their land higher than yours. There used to be a dipped area between your properties that collected water, but now, there is a hill that glides down onto yours. If your home suffers water damage as a result of this change, do you have any right to complain?
Generally speaking, neighbors aren't responsible for naturally occurring water damage to your property. There are times when your neighbors may be held liable for damage to your property, though. For instance, if the next door neighbors installed a large fountain that overflowed and caused your basement to flood, you'd have every right to pursue a claim.
If you want to pursue a lawsuit against your neighbor, you'll need to show that your neighbor altered his or her property in a way that was unreasonable or that led to a change in the natural flow of water. In your case, you could argue that it was unreasonable for your neighbor to leave the water on in the fountain or for him to build it so close to your basement that it could result in water damage.
Other neighbors might make mistakes like creating landscapes that alter how water flows onto your property. A good example would be if the neighbor built up the land on the property, raising up the front yard in a way that caused water to flow off his or her lawn and to collect on your property. This could cause your property to flood, even though his or her property would be clear and dry.
Your attorney can help you file a claim if you're worried about damage from your neighbor's property. Even if unintentional, those responsible should cover the costs.
Source: FindLaw, "Water Damage and Neighbor Disputes," accessed Aug. 11, 2017