At the culvert inlet, the project remit was to remove the sidewalls and arch at the inlet, and rebuild using Class B engineering brick.
We also had to rebuild the headwall and flank walls and construct an open-topped inlet chamber.
Erosion matting was installed to protect the embankment from further erosion. At the culvert outlet, the headwall, flank walls and the last metre of the culvert sidewalls and arch were rebuilt in reclaimed stone.
The floor, which had collapsed, was re-laid, and an in-situ concrete cascade was constructed at the culvert outfall. Loose and missing mortar beds were repaired throughout the length of the culvert.
Holmhead culvert is 75m in length, and was, originally, constructed in sandstone with a pitched floor of igneous flags.