American Transmission Co. projects

Project website for a Wisconsin-based company that owns and operates the high-voltage electric transmission system that powers communities in portions of the Upper Midwest.

North Madison-Huiskamp-Waunakee

PROJECT STATUS: Completed and in service

The North Madison-Waunakee Transmission System Upgrade was approved by the Public Service Commission in July 2007, construction began in spring 2008, and the line was completed and placed in service in April 2009. This project is a critical reinforcement to the electric system, which includes construction of a new 138-kilovolt transmission line from the North Madison Substation, located in the Town of Vienna, to the Huiskamp Substation, located in the Town of Westport.

Project Need

Dane County in recent years has experienced some of the highest growth rates in the state, both in population and electricity usage.Portions of Middleton, Dane, Waunakee, Vienna, Westport and the northeast side of Madison are supported by a network of 69-kilovolt transmission lines that are used to near-maximum capacity during the peak summer season. The existing transmission line through Waunakee was built in 1919 and is operating at the limits of its capabilities. Without the addition of the new line, the existing lines were projected to be overloaded in summer 2009, resulting in increased vulnerability to outages for communities across northern Dane County. There also is only limited opportunity to take these lines out of service for maintenance, which further compromises reliability and increases operating costs. To maintain reliable electric service, new transmission facilities are needed.

Completed line along State Road 113

Project at a Glance
Communities affected:Vienna, Waunakee, Westport; project benefits Dane, Middleton, Wauankee, Westport and Madison's northeast side.
Line length:Approximately 9 miles
Voltage:138,000 volts
End points:North Madison Substation (town of Vienna) to Huiskamp Substation in the Town of Westport.
Project certified in MISO’s 2018 Transmission Expansion Plan:Winter 2018
Apply for permits from U.S. Army Corps of Engineers / Michigan's Dept. of Environment, Great Lakes & Energy:Winter 2019-20
Remove portions of submarine cables 5 & 6:August - September 2020
Anticipated approvals from ACOE/EGLE:April 2021
Remove existing submarine cables 1-6:May - July 2021
Install and energize first new submarine cable:May - July 2021
Install and energize second new submarine cable:August - September 2021
In service:October 2021
Project complete:June 2022
Mitigation complete:Q3 2024
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