A customer wants me to add a drain to each of his flower beds near front sidewalk (2 beds total). There is already a 3" pvc drain pipe that runs directly through one of the beds. I just need to tap into that with a drain, then tee off of that to the left about 6' to the flower bed to the left. The pipe that tees off to the left has to go under a 3' wide concrete walkway. Then I would glue on an elbow there with a short pipe coming up and a second drain. The problem I'm having is envisioning how I'm going to tie into the existing drain pipe. Since I'll be coming into the middle of the pipe there wouldn't be much flex in it. Is there some way tie into it using a flexible hose? I have experience repairing sprinkler pipe and know there is funny pipe that can be used in these repair/addition situations. I have no experience doing drainage. Could somebody please give me some advice on this job?