What is the primary purpose of an endwall in a culvert?

The primary purpose of an endwall in a culvert is indeed to hold the embankment away from the pipe. Endwalls effectively support the structure and help maintain the integrity of the culvert by preventing soil erosion and collapse around the openings. They create a stable transition between the embankment and the culvert, ensuring that the flow of water is uninterrupted while also reducing potential damage to both the culvert and the surrounding area.

While aspects like aesthetics and water quality may be considerations in broader stormwater management, they are not the primary function of an endwall. Similarly, filtering sediments from the water is typically managed through other means, such as sediment basins or traps. The endwall serves a structural and protective role, which is critical in managing water flow and maintaining infrastructure stability.