Abstract: A modular cable trench system for receiving cable in a trench excavated in the earth. The system includes one or more tee and/or channel elements of lightweight modular construction, with each of the molded modular units including a bottom frame and opposed side plates secured to opposite side edges of the bottom frame with both side plates and bottom frame molded of lightweight material. Transverse reinforcing elements extend between the side plates at ends of the bottom frame and are molded integrally with the side plates and bottom frame. The geometric configuration of the bottom frame and transverse reinforcing elements is selected to minimize the weight of each modular unit. A removable cover plate engages the upper edges of the side plates in each unit.