Tay Street Drainage Upgrade

Christchurch

Scope:

  • Installation of 0.6 km NB600 to 900 mm stormwater pipeline through school and residential area
  • Construction of 11 stormwater manholes including 2 bespoke flow splitters
  • Replacement and reinstatement of 100 m wastewater line and associated laterals.
  • Open channel construction, retaining wall and landscaping.
  • Road and property reinstatement

Project Description:

This project in St Albans and Mairehau was an integral part of CCC’s larger land drainage recovery program to remediate the risk of seasonal rainfall flooding that increased in that residential area after the Canterbury earthquakes. The scheme was to intercept higher stormwater flows entering the area and split the load into parallel channels of increased combined capacity. The effectiveness of the completed scheme is noticeable in heavy rain events.

Project highlights included overcoming major challenges in dealing with the unstable, saturated ground as well as ensuring the many existing service crossings, particularly wastewater, were accommodated and reinstated as pipeline installation progressed. Significant effort also went into interacting and maintaining good relations with the Client, Stakeholders and Residents.

Client: Christchurch City Council
Consulting Engineers: GHD
Start Date: April 2017
Completion Date: October 2017