HDPE water and gas pipe v. Gophers

Question

I have an open trench and I might as well fill it with expensive plastic.

I went by the local irrigation supply to get 1 inch HDPE water line and was told gophers eat that around here (south-central WA) and I should stick with PVC. I want to avoid joints under the future patio.

I then realized I had ordered HDPE gas pipe for said trench. Will this get gnawed on by gophers too? I have a lot of gophers here although none of my surface PE irrigation lines have been damaged.

Is there any truth to this old wives tale or is it just rumors on the old-timey internet forums? Should I use copper gas lines to be safe? Local AHJ just shrugged at the question.

Answer 1

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" conduit or similar. They can't open their mouths enough to gnaw on it. But it's not an "old wives tale". Gophers can do a lot of damage to buried lines. So if I were doing this, I'd at least put in 2" 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.

Answer 2

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.

Answer 3

Here in Phoenix, AZ the gophers are a problem. Any buried thin wall black poly has a short life span. 4 year old 3/4" poly on the surface is doing fine so far, but sun exposure will be a limit for this. Plain old buried sch.40 PVC seems to hold up just fine. My incoming 1" PVC water line is 15+ years old. The various 7 year old 3/4" PVC SCH40 irrigation lines with a 12" bury are all doing fine so far. Not sure if PVC gas line would be an option. 20 years ago it had a problem with getting brittle from the odorizing agent. Don' know if this has been fixed.