South Central/Southwest Wisconsin and North Central Illinois
Zone 3

Transmission system limitations in Zone 3

Zone 3 is undergoing significant new generation interconnection requests and different projects that will allow their energy deliverability across the region. In addition, there are multiple projects that will increase the reliability, condition, and performance of existing transmission assets. 

Electricity usage growing

Electric load is forecasted to grow approximately 0.3% annually through 2032 in Zone 3. 

Transmission projects in Zone 3

The most notable planned, proposed and provisional network/asset renewal projects in Zone 3 are listed below along with their projected year of completion and the factors driving the need for the projects.

Zone 3 includes the counties of:
  • Columbia , Wis.
  • Crawford (S) , Wis.
  • Dane , Wis.
  • Dodge , Wis.
  • Grant , Wis.
  • Green , Wis.
  • Iowa , Wis.
  • Jefferson , Wis.
  • Lafayette , Wis.
  • Richland , Wis.
  • Rock , Wis.
  • Sauk , Wis.
  • Walworth , Wis.
  • Winnebago (N) , Ill.

Zone 3 Planned Projects

Project DescriptionProject #In-service yearNeed driver
Cardinal–Hickory Creek 345kV, line construction12023Reliability, Economic and Policy
Barneveld and Military Ridge SS, DIC, New Substations22023T‑D interconnection
Colley Road SS, Transformer Replacement and Asset Renewal 32023Asset Renewal
Gateway - Sycamore (6902), 69kV, rebuild 42023Reliability
J1000 Comet SS Network Upgrades and Interconnection Facilities52023G-T interconnection
J1003 North Beaver Dam SS Network Upgrades and Interconnection Facilities62023G-T interconnection
J1042 North Lake Geneva SS Network Upgrades and Interconnection Facilities 72023G-T interconnection
J1154 Crawfish River Solar Network Upgrades82023G-T interconnection
J947 Tennyson SS, Generator Interconnection Facilities and Network Upgrades92023G-T interconnection
Vinburn Substation 69 kV Capacitor Addition 102024Reliability, Condition and Performance
Nelson Dewey–Bloomington 69-kV (Y-184), rebuild & OPGW112025Reliability, Condition and Performance

Zone 3 Proposed Projects

Project DescriptionProject #In-service yearNeed driver
Rock County Reliability Project122024Reliability

Zone 3 Provisional Projects

Project DescriptionProject #In-service yearNeed driver
North Beaver Dam SS Asset Renewal &

South Beaver Dam – North Beaver Dam, 69kV (Y-59) Line Rebuild
132027Condition and Performance
Eden - Rock Branch 69kV (Y-106) Uprate142026Economic, Condition and Performance