A single gopher can inflict major damage on the plants and fruits in a garden within a brief time. The soil tilled up by gophers can damage or break parts of farming machinery as it passes over mounds of churned-up earth. In fact, horseshoe-shaped mounds of dirt are indicators of gopher activity nearby. Gophers may gnaw into utility cables, sprinkler systems, and plastic water lines to maintain their rapidly-growing teeth or to get a drink from your water supply. This is a more difficult kind of impact to assess because it is hidden from view.