What is the function of a headwall in drainage systems?

The function of a headwall in drainage systems is primarily to support a culvert pipe. A headwall is typically a concrete or masonry structure placed at the inlet or outlet of a culvert, which serves to stabilize the entrance and exit of the culvert within the surrounding soil. This support is essential for maintaining the alignment of the culvert and ensuring that the drainage system functions effectively without risking collapse or misalignment due to soil erosion or shifting.

Additionally, headwalls can help direct water flow into and out of the culvert, enhancing the efficiency of the drainage system. While other functions, such as energy dissipation and soil stabilization, are important considerations in overall drainage design, the primary role of a headwall is to provide structural support to the culvert system.