Culverts are crossing structures in running waters and allow the passage of water. They may be pipes that are laid under a road, allowing the flume to cross.
The culvert may be flowed through partially or in full, depending on the discharge occurring. A partially filled culvert with free surface is treated in the same way as an open channel, while a full flow through culvert corresponds to a pipe flow. By contrast, a full flow through culvert and a culvert in which the inlet is completely submerged are classed as control structures. These result in a limiting of the discharge. There may also be a combination of these two states, so that the culvert is in part fully flowed through and in part partially filled.
The culvert HM 160.45 contains two different channel bodies. The cross-sectional area of both open cross-sections is the same. The transparent material allows to observe closely the flow and occuring hydraulic jumps in the culvert.