The Manitoba–Minnesota Transmission Project includes construction of a 500-kilovolt AC transmission line in southeastern Manitoba and upgrades to associated stations at Dorsey, Riel, and Glenboro. The proposed route will:
- originate at the Dorsey Converter Station (located near Rosser, northwest of Winnipeg);
- travel south around Winnipeg and pass near the Riel Station (east of the city) along what is known as the Southern Loop corridor;
- continue south to the Manitoba–Minnesota border;
- connect to the Great Northern Transmission Line.
The Great Northern Transmission Line is to be constructed by Minnesota Power. It will terminate at Iron Range Station located northwest of Duluth, Minnesota. Subject to regulatory approvals, the projected in service date is mid-2020. The budget as of the spring of 2017 is estimated at $453 million.
Right-of-way and tower design
The right-of-way required for the transmission line will depend on the design of the tower structures. Predominantly 2 tower types will be utilized and will typically range in height from 40 to 60 metres. Spacing between towers will 400 to 500 metres apart on average.
- Self-supporting steel lattice structures will be used in cultivated crop lands (agricultural areas), to minimize impact on agricultural operations. Right-of-way width will be 80 metres for self supporting structures.
- Guyed steel structures will be used in non-cultivated lands. Right-of-way width will be 100 metres for guyed structures.
2 types of towers: guyed steel structure (left), self-supporting steel lattice (right).
Conductor-to-ground distances at maximum loading will meet the Canadian Standards Association standard for minimum ground clearance of transmission lines.
For the transmission line to be compatible with the existing system, modifications to both Riel and Dorsey converter stations will be undertaken.
Although distant from the proposed transmission line, modifications to Glenboro Station will also be required, including extending the current switch yard and installing additional equipment. Several towers on existing lines will be relocated to accommodate the station expansion (PDF, 2 MB).
Environmental assessment & route selection
An Environmental Impact Statement (EIS) was completed and submitted for regulatory review. The final preferred route has been determined for the project and submitted as part of the EIS. Feedback received through the engagement processes enhanced the environmental assessment work and assisted in determining the final placement of the transmission line.
Input received through the engagement and environmental assessment processes assisted in determining a final preferred route that is currently under regulatory review.
We used a process based on the EPRI-GTC Overhead Electric Transmission Line Siting Methodology to assist us in determining the final preferred route.
The Environmental Impact Statement (EIS) was submitted to Manitoba Sustainable Development for review. Read more about regulatory requirements.
The EIS for the project includes:
- study area characterization through fieldwork and background investigation;
- public and First Nation and Metis engagement to obtain feedback and input into route selection and the environmental assessment;
- identification and assessment of potential environmental and socio-economic effects;
- development of mitigation measures and monitoring plans;
- development of an environmental protection program.
The Manitoba–Minnesota Transmission Project timing is subject to change and is dependent on the issuance of a Class 3 development licence under The Environment Act (Manitoba) and federal approval under the National Energy Board.
- Public notification of project: August 2013 (completed).
- Round 1 engagement processes: October 2013 to February 2014 (completed).
- Refined alternative routes determined: February 2014 (completed).
- Round 2 engagement processes: March to December 2014 (completed).
- Preferred route determined: December 2014 (completed).
- Round 3 engagement processes: January to September 2015 (completed).
- Regulatory submission: September 2015 (completed).
- Anticipated regulatory review process: 2015 to 2017.
- Anticipated in service date: 2020.