Big Stone South to Ellendale Transmission Line

Index Map

A map from the developers showing the projects route. For a more detailed view, visit here.

Stated Purpose:

Montana-Dakota Utility and Otter Tail Power will use the 145 to 170 mile line to increase the capacity and reliability of the electrical grid in the area, as well as connect it to larger Multi-Value Projects across the region.The developers have also stated that the increase in capacity that this line will facilitate will help with the inclusion of additional energy sources, including wind energy.

Line Capacity:

345 kV

Route Description:

The route is planned to run from a new Big Stone South substation in South Dakota--part of the Big Stone South to Brookings transmission line--and will run to a proposed substation near Ellendale, North Dakota.

Once the project receives approval from state, federal, and local agencies; Otter Tail and Montana-Dakota will identify study corridors to determine the route and alternatives. After these corridors have been identified, the developers will hold public meetings to develop criteria they can use during the routing process to refine the large study corridors. Another round of public meetings will be held to receive input on potential routes, and the developers will use the feedback to identify the preferred route. This preferred route and an alternative will be submitted to the state utility authority for permitting.

The developers have posted a map of the study area, along with possible route corridors and the substation locations here.

Development Timeline:

Planning on the line was slated to end in 2012, with the line entering into the permitting and environmental review phase for the study area in South Dakota, which is required to be completed within a year. The developers planned to file for a route permit in North Dakota in August 2013. Construction for the project is set to begin in 2016, and the planned in-service date for the line is 2019.

Otter Tail and Montana-Dakota also note that if the routing and permitting phases take less time than expected, the entire timeline could be shortened for the project, and the the possible in-service date for the line could be as early as late 2017 or early 2018.

The developers used compiled feedback to determine a preferred route in June 2013. The route is now awaiting approval from state regulators.

Regulatory Process:

Otter Tail and Montana-Dakota have filed a notice of intent with the state utility authority. Next, the developers will have to file an application with the utility authority, which will then examine the proposed route, the need for the project, and the design of the line itself. After the state utility authority reviews the application, public hearings will be held to receive feedback on the route and possible alternatives. Once the hearings have concluded, the utility authority will issue its decision on the application from the developers.

Both utilities filed with South Dakota Public Utilities Commission for a permit to build the line in August 2013, with information hearings for the project expected to be held in October. Also in October, the developers filed for a combined corridor certificate and routing permit from the North Dakota Public Service Commission. They believe that ultimate approval will be obtained by August 2014 for the project. The SD PUC approved the permit in mid-August 2014, noting that a route should be chosen based on the least potential impact to dairy and agricultural operations.


Montana-Dakota Utilities Company

Otter Tail Power Company

Community Feedback:

The developers of the line held open house meetings for public feedback on the possible corridors for the line in October of 2012. Another round of community meetings is planned for the end of February 2013. Locations, along with dates and times, have been posted on the transmission line's site.

At a public hearing with the South Dakota Public Utilities Commission (PUC), numerous landowners voiced concerns over the project. Among the concerns were the safety of landowners if the lines were to go down over access roads, that the lines may damage local economic activity, and that it didn't seem necessary for the state. Some were also troubled by the information that had been shared at earlier meetings and discrepancies found in current information.

In early August, several opponents attended a SD PUC meeting to make comments on the project. Some members of the PUC noted that they would like more time to consider the project.

They have also provided a contact number that can be called for information about the transmission line: 1-888-283-4678

The project's website also provides a timeline of the project, and is located here.

Clean Energy Potential:

As stated above, the increase in capacity can assist in the inclusion of wind-generated power to be carried by the 345 kV line into the region as a whole, and give wind projects larger outlet for their production.

Fact Sheets:

Big Stone South to Ellendale Fact Sheet

Docket Filings:

Filings for a North Dakota corridor certificate and routing permit can be found here.

Filings for a South Dakota facility permit can be found here.

News Archive:

Lily man appeals PUC decision on Big Stone transmission line October 23, 2014

Transmission line sparks debate September 7, 2014

Transmission route through Brown County approved August 13, 2014

High-voltage power line across NE S.D. approved August 13, 2014

Big Stone power line decision delayed in South Dakota August 7, 2014

Concern voiced on proposed transmission line May 21, 2014

PSC Meeting in Ellendale Relocated April 1, 2014

Utility companies apply for new high-voltage line across NE South Dakota August 29, 2013

Planners have selected preferred route of BSSE transmission line June 9, 2013

Sending wind energy back east is one reason for proposed transmission line through northeastern S.D., October 30, 2012

$730 Million Transmission Line to Harness Wind Energy, October 18, 2012

New $300M power line to be explained at meeting, October 9, 2012

Otter Tail prepares to proceed with new transmission system, July 6, 2012

Your Thoughts:

We all know that clean energy transmission is vitally important to our energy future. It brings economic opportunity to rural areas, enables wind development and improves the reliability of your grid. But to build it properly - to create projects that work best for you and your community - requires your knowledge and participation.  That's why we've created this database.