LB civil were engaged as a subcontractor for the installation of an 1800 diameter SW pipeline with in situ built head walls, and a large underside concrete encasement of 95m3 of flowable fill being installed to the suspended pipeline, to avoid scouring and embedment displacement in high volume weather events. The project was an initiative of the Christchurch City Councils; to better manage the increased rainfall the hill-side area has seen over recent years, which has seen this area in flood several times. There was a large focus on onsite stormwater retention, planting and wildlife enhancement, and natural drainage of the wetland areas located throughout the valley, to ensure a reduced risk of flooding for the resident communities located throughout and below.