RECO designed and supplied 33m of TechSpan® precast arches and 118m² of TerraClass®, vertically ribbed retaining wingwalls, in lieu of twin box culverts for the Liverpool to Paramatta bus transit way where it passes over Orphan School Creek in the suburb of Prairiewood.  The design had to ensure temporary flood waters during periods of high rainfall, would flow safely through the culvert.  The project specific arch units were waterproofed along the joints during construction, which was conducted with minimal impact to the local residents and wildlife.