In order to meet the profile of the embankment or the proximity of the drainage outlet to the watercourse it may be necessary to provide an extended spillway in order to prevent erosion. There could also be a need to provide a wider, longer apron in order to reduce the velocity of the flow before it enters the watercourse.  Althon can offer several options; we can produce a separate casting as shown in the picture opposite, or we can modify a two part headwall to extend the apron and Wingwalls of a single piece headwall.