Gopher Expert here. You may have already solved your issue sorry I’m late to the party.
Pocket gophers can and do chew through all pipe with the exception of metal. However, they will tunnel around the pipe, including community and hydrant lines. Without the soil, vibration occurs and the joints, nuts and bolts will come apart. I had one customer that had this happen to their hydrant line and it created a massive blowout of our states largest flood control levee, to the tune of 3 million dollars.
I always suggest to my customers when running in the ground, for generations of no worrying, run all wiring, tubes, gas and electrical lines inside PVC pipe, INSIDE a trench. Frame out the ends and when everything is laid out, pour concrete on top and seal the pipes. This will protect the pipes from heat if in states like my own, Arizona, or freezing temps in so many others. If you ever have any issues, you’ll be able to easily pull new line through, if ever needed.
One thing to note, pocket gophers are incredibly intelligent and will use anything and everything we put in or on the ground, so be aware that they do tunnel under and alongside walls, pony walls, curbing and sidewalks are their favorites as they can tunnel for miles and never be detected. Those tunnels intersect with hundreds more, all inbreeding, never hibernating, just making a mess. So if you have gophers, trap and kill them. They are Herbivores and will not eat poisons, baits, and grain or seed, they simply push it aboveground where birds ingest, take flight and then fall to the ground where dogs, cats and wildlife eat and are also killed.
Have any questions I can help with, let me know. I’m happy to help.