After the quake - rebuilding an entire city water network

Abstract

In February 2011, a 6.2 magnitude earthquake struck Christchurch, New Zealand causing devastation to buildings, roading and infrastructure. Over 6,500 people were injured and 185 people lost their lives.

Following the quake, Christchurch City Council (CCC) was faced with rebuilding the city’s 3 water pipeline network. The existing polyethylene (PE) watermain network performed well during the quake and CCC chose PE as the material of choice for all rebuilt water and wastewater pressure pipelines.

Although PE has been used in pipe networks since the 1960’s, a lack of knowledge and experience surrounds electrofusion, one of the main methods used to connect PE pipes. Installation inexperience amongst construction workers on Christchurch’s rebuild, caused failures rates of 30% of newly installed PE watermain pipeline joints.

CCC implemented an oversight system to monitor welder performance. Within 12 months of the system’s establishment, electrofusion and butt weld test failures fell to less than 1%.

Today Christchurch has a world class pressure water and sewer network as a result of the system introduced following the quake.