The State Treasurer asked the Economic Regulation Authority (ERA) on 23 April 2010 to conduct an inquiry into the overall costs and benefits of the State Underground Power Program.

In accordance with the Terms of Reference, the ERA was to have regard to:

the costs of undergrounding the overhead electricity distribution network;
a comparison of the costs associated with maintaining the current distribution network compared to undergrounding;
the types of costs which are avoided as a result of undergrounding the overhead electrical distribution system;
the identification and quantification (where possible) of all costs and benefits of underground power; and
an analysis of the distribution and timing of benefits, including an appraisal of who benefits and the overall public benefit to the wider community.
In particular, the ERA was to report on what the appropriate share of funding is between the Government, individual households and Western Power.

The cost benefit study was limited to the undergrounding of power in the South West Interconnected System.

In conducting this inquiry the ERA has published:

- an issues paper on 28 June 2010 to help interested parties understand the matters under review and to facilitate public submissions; and
- a draft report on 1 July 2011 for further public consultation. The submissions received in response to the issues paper and draft report are published on the ERA's website; and
- a final report outlining the costs and benefits of the SUPP major residential projects and proposed changes to the share of funding between the Government, individual households and the wider community.