Since you were not asked , my question then I will and then I have to get my butt to bed , IS your property just a tiny bit higher than the neighbors EVEN if its as little as 2 or three inch lower than yours ? I ask this because water run off if their lot was lower even before you built then you wouldn't have been for rain run off going onto their lot, your not responsible for skeets either since they also travel on wind / with wind their complaint about not being able to party is hog wash , they could have moved their parties to the front yard and BBQ grilled in the driveway or had the parties indoors . It appears you have moved next to someone who is either sue happy or is from the Entitled people club