All links in the physical supply chain contribute to providing gas users with a secure and reliable gas supply. The security and reliability (S&R) of transmission pipelines is particularly important, given that a transmission outage has the potential to cause widespread supply interruptions. The last significant interruption to gas transmission in New Zealand was in October 2011 when the Maui pipeline failed due to a landslide at Pukearuhe in northern Taranaki. The Ministry of Business, Innovation and Employment estimated that the gross cost of the outage to the economy was $200 million. The event prompted pipeline owners and operators to re-assess risks, increase monitoring, and invest in additional preventative maintenance at high risk sites.
The introduction of new information disclosure requirements in 2012, as one element of a price-quality regime under the Commerce Act greatly improved the transparency of S&R. In particular, the owners of open access transmission pipelines were required to publish their Asset Management Plans (AMPs). However, stakeholders found the information difficult to understand, and concerns about transmission pipeline S&R remained. This prompted Gas Industry Co to review the factors influencing S&R and assess their adequacy. It published its findings in a 2016 Issues Paper.