When I bought my house 5 years ago, there was a swale on the very edge of my property. During heavy rains, water from my neigbors yard drained through the swale. My neighbors downspouts point directly to the very edge of his property near mine, generating most of the water running through the swale. My downspouts all run through underground drain lines to the street.
After years of maintaining the swale on behalf of my neighbor. I decided to replace the existing swale with undergroung drain pipe. I proceeded to dig out the swale, add a catch basin and a 4" drain line and routed it to the street. I backfilled and leveled the area where the old swale was.
My neighbor came over to ask what the provisions where when the drainage failed. I told him that since my yard is lower than his, excess water will still flow down my lawn as I have not raised the elevation to block water flow. He decided to add that it was illegal to block the natural flow of water(he's a town cop, so I guess he felt the need to throw in the word illegal).
Have I dome something wrong? Am I obligated to deal with my neigbors runoff from his roof even when he has not made a good faith attempt to run drain lines to the street like everyone else.
PS: Most of the homes in my neighborhood have 70x100 lots. There are homes directly behind both of us, then another street(so there are no other sources for excessive water). Most of the homes in the neighborhood have drain lines to the street. My neighbor apparently did, but when the clay lines became clogged 15 years ago, they decided it was easier to just have it dump on to my side. From what I have heard, the guy who used to own my house created the swale as a solution to his water problems and my neigbors. After it was created the owner of my house decided it was not sufficient and opted to install 4" drain pipe to the street for all of the down spouts. My neighor continued to use the swale.