Project description

The Manitoba–Minnesota Transmission Project includes construction of a 500-kilovolt AC transmission line in southeastern Manitoba and upgrades to associated converter stations at Dorsey, Riel, and Glenboro. The transmission line:

  • starts at the Dorsey Converter Station (located near Rosser, northwest of Winnipeg);
  • travels south around Winnipeg and passes near the Riel Station (east of the city) along what is known as the Southern Loop corridor;
  • continues south to the Manitoba–Minnesota border;
  • connects to the Great Northern Transmission Line.

The Great Northern Transmission Line will be constructed by Minnesota Power. It will terminate at Iron Range Station located northwest of Duluth, Minnesota. 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

Two types of towers for the project: a tall, thinner guyed steel structure, and a shorter, wider self-supporting tower.

Towers types: guyed steel structure (left), self-supporting steel lattice (right).
Enlarge image.

The right-of-way required for the transmission line depends on the design of the tower structures. Towers will be mostly 2 types (guyed and self-supported) 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 towers will be used in cultivated crop lands (agricultural areas), to minimize impact on agricultural operations. Right-of-way width will be 80 metres for these towers.
  • Guyed steel towers will be used in non-cultivated lands. Right-of-way width will be 100 metres for these towers.

Conductor-to-ground distances at maximum loading will meet the Canadian Standards Association standard for minimum ground clearance of transmission lines

Station modifications

For the transmission line to be compatible with the existing system, modifications will be made to both Riel and Dorsey converter stations.

Although distant from the proposed transmission line, modifications to Glenboro Station will also be made, including extending the current switch yard and installing additional equipment. Several towers on existing lines will be moved in the station expansion (PDF, 2 MB).

Environmental assessment & route selection

An Environmental Impact Statement (EIS) was completed and submitted for regulatory review. Feedback received through the engagement processes enhanced the environmental assessment work and assisted in determining the final placement of the transmission line.

Route selection

Input received through the engagement and environmental assessment processes assisted in determining the final preferred route.

We used a process based on the EPRI-GTC Overhead Electric Transmission Line Siting Methodology to assist us in determining the final preferred route.

Environmental assessment

The Environmental Impact Statement (EIS) was submitted to Manitoba Sustainable Development for review. Read more about regulatory requirements.

The project EIS included:

  • 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.

Schedule

  • 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 2019 (completed);
  • Anticipated in service date: 2020.