Western Sewer Pumping Main
Planning Started: 2000
Construction Started: November 2011
Completed: March 2012
A major project for Napier, the western sewer main was triggered by the need to boost system capacity in a growing city.
The main serves housing developments that were recently established, are underway or are planned for the future – the Oaklands, Parklands, Citrus Grove (Pinotage) and the proposed Mission Heights and Park Island (Wharerangi Road / Westminster Ave) subdivisions.
Allowance has also been made to accommodate flows from a business park which is planned for a greenfields area north of Prebensen Drive and west of the Hawke’s Bay Expressway.
The new sewer main connects to the Pinotage, Parklands and Wakefield pump stations, and there is provision for a further pump station to handle wastewater from the proposed business park.
The route for the 3.1 km polyethylene pipeline follows Westminster Avenue north from Clyde Jeffery Drive, under the expressway to Taradale Road.
Construction was completed with the connection to the chamber at Taradale Road. This chamber will feed into the new Taradale Road pump station once that project is completed.
The pipeline was largely constructed by Napier City Council works staff using conventional open trenching methods. Contractors installed four sections employing directional drilling methods, avoiding logistical issues of open trenching across drains and roads which would have disrupted traffic and added to the overall cost.
Unlike concrete or cement-lined steel pipe, the polyethylene pipes chosen for the new main are not subject to corrosion. The welded pipe joints minimise the risk of root and groundwater intrusion and leaks through joins.
The pipe is flexible, moving with the soil if it settles or shifts, and the polyethylene material also handles fluctuating pressures well.
The western sewer pumping main was an $800,000 project.