We had a spot in our yard that was always wet. Had it dug up when we put in a new driveway last year, and it turned out that it was a pipe coming from the curtain drain around the foundation. The idiots that put it in just had it randomly stop in the yard, instead of carrying it another 50' to the drainage line that feeds into a man made pond. So of course I had to tack on 50' of new drainage to the cost of the driveway, topsoil, reseeding, etc.