Culverts

A drainage culvert is a structure, such as a pipe, that allows water to freely flow under various obstructions. These pipes provide effective stormwater management allowing the free flow of water under roads, trails, and railways.                  Made of concrete reinforced by British Reinforcement Concrete (BRC) wire mesh.

Comes in various sizes 300mm, 450mm 600mm, 750mm, 900mm Diameter etc and the choice of use depends entirely on purpose.