Bury cables from 12-36 inches (or 30-90 cm) deep. Where plant life, sidewalks, and other utilities already disrupt earth, it's safer to bury at as little as 24 inches or 60 cm, using protective conduits to limit the likelihood of damaged cables by inexperienced maintenance or. Bury cables from 12-36 inches (or 30-90 cm) deep. Shallower depths are permissible when individual lengths are placed within conduits. 2 meters (3-4 feet) deep to reduce the likelihood of accidentally being dug up. In extreme cold climates, cables may need to be buried at greater depths where there temperatures are colder and frost penetrates to. When planning a fiber optic network installation, one of the most common questions is: How deep are fiber optic cables buried? Proper burial depth is critical for the safety, durability, and performance of your communication infrastructure. (FOA) was founded in 1995 to help develop the workforce to build the fiber optic networks to support a rapid expansion in communications and the Internet. In high-load areas such as roads or backbone routes, burial depth can reach 48 inches (120 cm) or more. Several technical and environmental factors dictate the optimal burial depth: Rocky Terrain: Requires 1. 5 meters to avoid 1000 N/cm crush damage, common in mountainous regions.