The regional planning cycle begun in 2014 for the Greenstone-Marathon sub-region was completed in June 2016 and an Integrated Regional Resource Plan (IRRP) was released.

Community Engagement

The IESO engages with local and regional communities to seek input to help inform regional planning activities. An Integrated Regional Resource Plan (IRRP) from the latest Greenstone-Marathon planning cycle was finalized in 2016. See engagement materials on the previous planning cycle.

Regional Planning Process Outcome (IRRP)

Planning for the Greenstone-Marathon sub-region is driven by community growth, as well as potential demand from new industrial customers, primarily in the mining and forestry sectors, along with a large pipeline project. Combined, industrial projects could result in more than 150 MW of new demand.

The Integrated Regional Resource Plan (IRRP) will also consider ways to ensure long-term flexibility associated with the Ring of Fire mining development and other mining claims.

Documents referenced on this page, but not posted, can be obtained by contacting with a link to the web page that lists the document and advise whether it needs to be provided in an accessible format. Please allow a minimum of one business day for a response.

2016 Greenstone-Marathon IRRP - Appendices
Key Resources
2016 Greenstone-Marathon IRRP Backgrounder

Greenstone-Marathon Interim IRRP

Greenstone-Marathon Interim IRRP Appendices

Attachment – 2011 Transmission Unit Cost Study – SNC Lavalin

Final Northwest Region Scoping Assessment Outcome Report

Draft Northwest Scoping Assessment Outcome Report


IRRP Working Group - Next Steps

The Greenstone-Marathon IRRP Working Group, led by the IESO, and consisting of members from Hydro One Networks Inc. (both transmission and distribution functions) will use the regional planning process to identify and meet local electricity needs.

Area Overview

The Greenstone-Marathon sub-region extends east from the eastern shore of Lake Nipigon including the Municipality of Greenstone, up to and including the Town of Marathon. A full listing of the municipalities in the regional planning area can be found in the terms of reference.

The Greenstone-Marathon sub-region also includes the following First Nations:

  • Red Rock
  • Bingwi Neyaashi Anishinaabek ("BNA")
  • Biinjitiwaabik Zaaging Anishinaabek ("BZA")
  • Animbiigoo Zaagi'igan Anishinaabek ("AZA")
  • Long Lake #58
  • Ginoogaming, Aroland
  • Pays Plat
  • Ojibways of the Pic River
  • Pic Mobert

Electricity to the sub-region is currently supplied from the 115 kV transmission system emanating from the Alexander Switching Station near Nipigon and Marathon Transformer Station in the Town of Marathon.

Historical Context

During municipal engagement activities for the North of Dryden IRRP, the OPA (now the IESO) met with municipal representatives from Greenstone and Marathon. The IESO has also had conversations with representatives and members of a number of First Nation communities in the area. The IESO has confirmed that local economic development in the area warrants the development of a regional planning study.