When there’s a problem with pipes inside my house, I get that it’s my responsibility, so I call a pro, get it fixed and that’s that. But what if it’s pipes outside, like under the sidewalk or the street that’s the city’s job. But what about the backyard? It’s not really the house, but it’s not the street either.

Anything within your property is your responsibility, and the backyard is definitely your property. It’s not some hidden info, you can easily google who is responsible for maintaining water pipes in Seattle, for example. By the way, Ben’s Plumbing works great in Seattle, so if you ever need top-notch plumbers, I highly recommend them.