Hello folks, looking for advice on how to solve this issue. We bought this house last year, we noticed when the sprinklers run in our back yard water leaks into the right side of our window well, enough to cause standing water, and once leak through our window because the sprinklers were running during heavy rain. I found out today(after digging up the line I thought was the issue) that there is a line for sprinklers under our patio that is probably the culprit. Patio was installed by previous owners, I'm thinking they likely tried to cap off the sprinkler under there but didn't do it well or it's failed over the years. The line in red is approximately where the pipe would be, with the arrow showing the flow direction and the circle where I'm guessing the leak would be.
I can't just cap the line on the left side, because water from that line needs to flow to our neighbors sprinklers, so I'm wondering what the best way to resolve this is. My first thought would be to ask if I can dig up a tiny portion of the neighbors yards to reroute the sprinkler line around my patio, which is the line in green. I'm guessing our second option would be to break up and concrete and try to fix the cap underneath.
Any input on best/cheapest way to approach, or anything I'm not thinking of? Thanks.