South Central/Southwest Wisconsin and North Central Illinois
Zone 3
Transmission system limitations in Zone 3
Zone 3 is undergoing significant new generation and load interconnection requests resulting in 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 0.9% annually through 2035 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 Description | Project # | In-service year | Need driver | Regulatory Update |
|---|---|---|---|---|
| J1410 J1411 North Arlington Swt St MPFCA & Network Upgrades | 1 | 2026 | G-T Interconnection | CA Approved in 2023 |
| Darlington – Rock Branch 69kV (Y-109), Rebuild | 2 | 2026 | Condition and Performance | n/a |
| North Lake Geneva – Elkhorn 138 kV (X-55), Rebuild | 3 | 2026 | Reliability | n/a |
| Dodge County, DIC, New Substation | 4 | 2027 | T-D Interconnection | CPCN Approved in 2025 |
| Grant County, DIC, New Substation | 5 | 2027 | T-D Interconnection | CA Filed in 2024 |
| Columbus SS, DIC, Reconfiguration | 8 | 2028 | T-D Interconnection | CA Targeted filing 2026 |
| Eden – Rock Branch 69kV (Y-106), Rebuild & OPGW | 11 | 2028 | Economic, Condition and Performance | n/a |
Zone 3 Proposed Projects
| Project Description | Project # | In-service year | Need driver | Regulatory Update |
|---|---|---|---|---|
| Portage – Columbia 138 kV (X-13/X-20), Reconductor | 6 | 2027 | Reliability | n/a |
| Highland – Hill Valley 138 kV, Construct New Line | 7 | 2026 | Reliability | n/a |
| Dane County, DIC, New Substation | 9 | 2029 | T-D Interconnection | CA Targeted filing 2026 |
| Sun Prairie Area Reliability Project | 10 | 2029 | Reliability | CA Targeted filing 2026 |
Zone 3 Provisional Projects
| Project Description | Project # | In-service year | Need driver | Regulatory Update |
|---|---|---|---|---|
| Zenda – Katzenberg 69 kV (Y-51 ALE), Partial Rebuild | 12 | 2028 | Condition and Performance, Reliability | n/a |
| Hillman - Falcon - Darlington 138 kV (X-14/X-101), Double Circuit Rebuild | 13 | 2031 | Condition and Performance, Reliability | n/a |
| Fitchburg SS Control Building, Relay, Breaker and Remote Ends Asset Renewal | 14 | 2029 | Condition and Performance | n/a |