Customer: CERA / NZTA / CCC
Contract type: Alliance
Location: Christchurch, New Zealand
Construction Period: 6 years
McConnell Dowell, as a memebr of the Stronger Christchurch Infrastructure Rebuild Team (SCIRT), rebuilt Christchurch’s earthquake damaged infrastructure, undertaking the biggest civil construction program in New Zealand’s history. Consecutive earthquakes in September 2010 and February 2011 inflicted a significant amount of damage throughout the city.
The main works undertaken by the McConnell Dowell team included network drainage works, roading, kerbing, stormwater and water main repair, pump station construction, repairs to retaining walls, pressure wastewater installation involving the replacement of a new sewer main and installation of pumps on private properties, vacuum wastewater reticulation and vacuum station construction.
With works valued in excess of NZ$100 million per year over five years, resource allocation and works planning were key challenges for the management team. Local resources were strained, meaning many subcontractors had to been drawn from other areas around New Zealand and internationally. Differing health and safety, environmental and quality standards meant extensive training was required for these crews. With much of the SCIRT projects centred in residential areas, stakeholder management was a key focus of the SCIRT project team. Months of disruption caused by repair works placed additional strain on residents already stressed by sometimes extreme property damage.
The scale of rebuilding works required a detailed planning process and the programme of works was prioritised against set criteria and each delivery team was awarded a percentage of work based on their performance in Key Results Areas (KRAs) against a 20% baseline. This approach provided a strategic, city-wide perspective to minimise the impact on the people of Christchurch and create value for money. Significant projects included:
- Wairakei Diversion – Construction of a new pipe running through Fendalton. The project required repair work to water supply and stormwater infrastructure, including the installation of an 825 mm dia concrete main trunk sewer and 150 mm dia collector, plus kerb and channel by dig and lay methods, and the upgrade of the road along the 1 km pipe route.
- Gayhurst Road Bridge - Construction of a temporary pedestrian and cycle bridge and demolition of the existing bridge. McConnell Dowell, in conjunction with the designers, developed an alternative design using pre-cast panels that were cantilevered onto the bridge, which expedited the programmed works, and reduced the environmental risks of working over water.
- Carlton Mill Footbridge needed to be repaired in a manner that would preserve the bridge’s heritage.
- Southern Relief, Linwood – A large scale project with works centred on Worcester Street and Woodham Road. The dig and relay of the 1.6 m x 1.2 m concrete pipe takes wastewater from approximately 200,000 households around Christchurch to the Bromley Treatment Plant and is essential to the wastewater network in Christchurch.
Key to Success
Close interaction with residents, businesses and developers was a key element of McConnell Dowell’s approach to support the rebuild of Christchurch. We developed a number of innovations to minimise disruption to residents and provide safe and resilient infrastructure. We constructed a section of Orion’s 66 kV underground power service and introduced a Cured in Place Pipe (CIPP) to support stormwater repairs on Christchurch’s port hills and installed a vacuum wastewater system in the residential suburb of Shirley - the first area of the South Island to use such technology.