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​​​​​​​​Critical Contingency Operator Overview

Gas Industry Company appoints Critical Contingency Operator

Gas Industry Co (GIC) administers the Gas Governance (Critical Contingency Management Regulations 2008) Regulations. The purpose of the Regulations is to achieve the effective management of critical gas outages and other security of supply contingencies without comprising long-term security of supply. The Regulations achieve this principally through the appointment of a Critical Contingency Operator (CCO) which has a range of powers, particularly to curtail gas consumption during critical contingencies.

Core Group Ltd has been appointed as the CCO, effective from 1 March 2014.

The role of the Critical Contingency Operator includes to:

  • determine and declare the onset of a Critical Contingency
  • call for load curtailment as required to balance the system
  • continuously monitor the supply/demand balance and adjust load curtailment directions as necessary; and
  • determine when it is safe to terminate a Critical Contingency;

Critical Contingency Process

Critical Contingencies occur when there is a shortage of gas supply relative to demand.  The pressure on the Transmission System can fall to a point where intervention is required to ensure that a sufficient supply of gas is maintained in the Transmission System to supply distribution networks and domestic consumers. 

CC Events

When a serious issue or Critical Contingency event arises on or affecting the Gas Transmission System the Transmission System Owner (TSO) contacts the CCO and provides information and advice regarding the situation and the potential impacts on the transmission system's ability to supply the gas demand.

CCO Process Diagram.jpg 

The Transmission System Owner (TSO) remains in direct control and management of the transmission system at all times by activating processes and procedures contained within their Critical Contingency Management Plan (CCMP) and emergency response plans. 

CCO Directions

Depending on the situation and in accordance with the requirements Critical Contingency Regulations, the CCO may issue a range of instructions to the industry designed to ensure that the gas transmission system regains balance between supply and demand. This includes declaration of a potential or actual Critical Contingency. Declaration of a potential Critical Contingency provides early warning of the situation to industry participants.

When an actual Critical Contingency has been declared, it is likely that further directions will also be issued by the CCO requiring gas users to curtail demand.

These requirements do not generally affect domestic customers.

When the situation has been resolved, the CCO will issue further instructions to industry participants to restore demand (i.e. resume consumption of gas) and declare the termination of the Critical Contingency.

The TSO must comply with the directions of the CCO given under the Regulations.

The CCO must issue directions to the TSO that are consistent with the relevant Critical Contingency Management Plan and the CCO Communications Plan.

The TSO must issue directions to Retailers and Large Consumers that are consistent with the Critical Contingency Management Plan.

When the CCO issues notices to the TSO of directions to curtail demand, revise curtailed demand or restore curtailed demand, the CCO will provide a copy of such notices to Retailers, Large Consumers and Stakeholders.




18 July 2017

System Imbalance Critical Contingency Performance Report

The CCO has published a Final Performance Report for the Critical Contingency declared on 23 May 2017.  It is available here under Historical CC Events.​

Annual Exercise

Exercise Interface was carried out on Tuesday 11 April 2017 to test the First Gas Ltd Critical Contingency Management Plan. The CCO's Final Report for the exercise is available here under Historical CC Events.


April 2017

Industry Training

The CCO held training sessions on the critical contingency management process as follows:

Auckland           Tues 14 March

Wellington        Weds 15 March

New Plymouth   Tues 21 March

The slides used as the basis of the presentation are available here


Industry Links:

Gas Industry Company

First Gas Limited



Interested Parties:

If you would like to register as an Interested Party and receive direct email notification of Critical Contingency events, please register your request using the Contact Us form.