On 26 February 2026, the Australian Energy Market Commission (AEMC or Commission) published a draft determination and draft more preferable rule in response to a rule change request from the Chair of the Energy Senior Officials and the Victorian Minister for Energy and Resources (the proponents) to amend the National Gas Rules (NGR). The rule change requested the implementation of a reliability standard and related reliability tools for the East Coast Gas System (ECGS).  

We are seeking your feedback on the draft rules  

The draft determination and rule propose three key changes:  

• a three-tiered risk or threat signalling framework for AEMO to assess, classify and communicate risks or threats to reliability and supply adequacy in the ECGS  
• governance arrangements for the review of Declared Wholesale Gas Market (DWGM) and Short Term Trading Market (STTM) market settings with the establishment of a Gas Reliability Committee (GRC)
• enhancements to AEMO’s gas statement of opportunities (GSOO) and Victorian gas planning reports (VGPR) to include additional information in the gas supply adequacy assessments.

The Commission assessed the feasibility of a reliability standard for the ECGS as proposed in the original rule change request, but has not progressed this proposal in the draft rule. Instead, the Commission considers the arrangements introduced by the draft rules will provide fit-for-purpose, principles-based frameworks that would promote efficient market-led responses, balance implementation considerations and promote flexibility for AEMO and the proposed GRC. 

Next steps

Written submissions responding to the draft determination must be lodged with the Commission by 9 April 2026.

On 13 March 2026, we will host an online information session for stakeholders, covering this and the supplier of last resort (SoLR) draft determinations. Details about this session, including a registration form are available on the AEMC website.

Background

This rule change request is one of four rule change requests that seek to improve the reliability and supply adequacy (RSA) of the ECGS.  

The changes proposed by the four rule change requests intend to build the second stage of an RSA framework, complementing the first stage changes to the NGR applied to the ECGS (stage 1).

The stage 1 changes became effective in May 2023 and expanded AEMO’s powers under the National Gas Law (NGL) to better manage gas supply adequacy and reliability risks in the ECGS from 2023.

Of the four stage 2 rule changes, one has been completed (Notice of closure for gas infrastructure).  

Rule change process

• The Commission published a consultation paper for comment on 9 March 2025, alongside a background paper with information on relevant features of the ECGS and the gas markets, as well as a description of the key components of the existing NEM reliability standard.
• The Commission published a directions paper on 28 August 2025, which considered the overarching problem presented in the rule change request through an operational, investment and planning lens and sought stakeholder feedback.
• On 27 November 2025, the Commission extended the time for making the draft determination to 26 February 2026, as the rule change presented issues of sufficient complexity and difficulty.
• On 26 February 2026, with the publication of the draft determination, the name of the rule change was updated from the ECGS Reliability standard and associated settings rule change to the ECGS Enhancing reliability and supply adequacy arrangements (ERSAA), to more accurately reflect the contents of the draft more preferable rule.