Originally this work comprised of the construction of two reinforced concrete headwalls on the ends of an exisiting brick culvert, with a short connecting section of precast concrete box culverts at the upstream headwall. Subsequent inspection of the existing culvert showed it to be structually defective. The exisiting stream was diverted around the proposed works and the exisiting culvert demolished.
Even with the stream diverted 24 hours a day pumping was required to keep the excavation dry enough to construct the works.
The headwalls were built to meet the local highway authority requirements and a very high level of accuracy was required to ensure these were met. The installation of a precast concrete box culvert 60m in length, 3300mm wide and 1500mm on a reinforced concrete bed was completed in a two week period with the brick clad insitu concrete headwalls constructed at each end on completetion. The upstream headwall incorporated a removable flow restricting section. On completion of the reinforced concrete work the culvert and stream diversion were backfilled and made good.