HDPE water and gas pipe v. Gophers
I feel your pain, I live in Western Washington and have the same issue.  One way to protect against gopher damage is a larger pipe. Like 2&quot; conduit or similar.  They can't open their mouths enough to gnaw on it. But it's not an &quot;old wives tale&quot;.  Gophers can do a lot of damage to buried lines.   So if I were doing this, I'd at least put in 2&quot; conduit (or pipe) in areas that would be difficult to access later.   If you want to go further, put it all in conduit.  Depending upon how long the run is, it's not really all that expensive and good insurance.