The passage is composed of multiples poles being placed around the corridor along with some other equipment. The place appears to be under construction. The fence up ahead block between the path toward the sewer passage.
For Leon, he can venture into this passage and enter the sewer storeroom, however he cannot go any further toward the sewer passage because the hole of the broken fence is to small for him to fit through.
As Claire however, Sherry is encountered here. She will enter through the fence to explore the area of the Sewage disposal plant.