The short answer, based on general industry standards and the National Electrical Code (NEC), is that fiber optic cable is typically buried between 24 inches (60 cm) and 30 inches (76 cm) deep. However, simply hitting this depth isn't enough to guarantee your network survives. This article covers cable selection, trench preparation, tracer wire, warning tape, road crossings, and. d suppliers of electrical construction services. Existence. The Fiber Optic Association, Inc. Burying these cables protects them from physical damage, weather, and unauthorized access, but the depth varies based on location, cable type, and local.