Stormwater (SW) Ōtākaro Avon River Corridor Stopbank Anzac Drive to Waitaki Street (OARC)

Summary and scope

The Works for this RFT shall include, but are not limited to: SP1 – Anzac to Waitaki Flood Protection: • Sheet‑pile floodwall and embankments – installation of STU2700 sheet piles, core material tie‑ins, toe drains, earth embankments on both sides, and safety barrier along Anzac Drive. • Stormwater and groundwater infrastructure – new gravity reticulation, swales, debris screen structure, stormwater pump station (3 × 0.5 m³/s pumps), northern groundwater pump station, rising mains, distribution chamber, and river outfall works. • Roading upgrades – full reconstruction and raising of Wainoni Road to RL 2.92 m, new shared paths/cycle lanes, sump adjustments, and service relocations. • City to Sea Pathway and access works – 4 m‑wide asphalt pathway on embankment, access tracks, small culvert installations, and tie‑ins to existing routes including Falconwood Grove. • Landscaping and siteworks – ecological planting, reserve works (incl. Jack Hinton Memorial relocation), architectural electrical building, fencing, contaminated soil handling, earthworks, and site reinstatement. SP2 – Waitaki Treatment Facility: • Construction of a stormwater first flush basin that will provide storage and treatment of first flush volume runoff from the adjacent urban catchments. • Construction of twin stormwater treatment wetlands which, in addition to treating stormwater, will provide ecological benefit by providing habitat for birds and other wildlife. • Construction of the final length of the upstream piped connection with associated manholes. • Abandonment of remaining stormwater and wastewater pipes that are in Bexley Road and removal of almost all services that are below the formation level of the stormwater management facility.