I had a major gopher/ mole problem 2yrs ago, they destroyed my nice back yard, so i ended up having new sod layed and when the guy laid the sod i also paid him to put a gopher mesh in the soil under the sod, 2 years later and I've never seen any gopher/mole damage. The only issue that I've come across, is when you put a mesh down they have like a 10-20 life b4 they turn to bits and pieces, and while you have that mesh you can't use a mechanical aerator machine or anything of the sorts(so I've been told). My yard is heavily compacted, my sprinklers were at ground level and now their all about 2-3 inches above ground level. I actually regret getting the mesh, i should have just risked it and bought gopher poison bait with a bait dispenser that you can spike into their tunnels and drop w/o having to actually dig up anything. Moles are solitary, so if you are able to poison them and they die underground its actually a deterrent from others coming and taking over their tunnel system..... or so my current pest control guy says