Gopher killing...

For the last two years ..two small holes...
All of a sudden, my yard looks like molten sand hills.. Pumped three hours of pipe water , so far ... I know about road flare sulphur, I thinking the beasties,has dug too many trenches . I prefer no poison, don't want to hurt local pets...
Any, Ideas ?

THIS WORKS !
I had terrible gopher problems, they were tunneling out underneath the double carport that is attached to my house. The carport asphalt has even sunk about 3/4" in most of it, to where water was standing under the carport . ICE IN WINTER. I took the muffler off one of my pushmowers, and piped the exhaust down into a hole in the front yard, sealed the hole ,left it running and went and mowed the church lawn (about 8 acres), when I got home the mower was out of gas, I refilled it and let it run out again. That was last spring,a little over a yr ago, ''still don't have any gophers''.
The best way would be to come up w/ an old 3/4" gas range connector, use the appropriate fitting ( reducer) and nipples to hook it up, so u could get it piped into the hole easily, be sure to seal around the pipe where it goes into the hole w/ something that won`t burn.
I guarantee this !!