Through the advancements of hydraulics in the past century, culverts have become an essential to roadway transportation. They server as cross-drains relief by passing water under roadway at natural drainage and stream crossings or as pedestrian crossings or animal crossings under roadway.
Environmental impacts are a priority when it comes culvert design. Safe and stable stream crossings need to accommodate wildlife and protect stream flow while reducing structural damage from erosion.
During new or replacement of culverts, techniques are used to have minimal impacts on both the environment and transportation. This includes having short term impacts on the aquatic biology and prevention of energy loss of the water flow.