Jefferson County, Wisconsin: Power, Data Centers and the Local Economy
Home to Watertown, Fort Atkinson and Jefferson
Jefferson County is not a build-out site today. It feels the boom through the grid it shares, the utilities that serve it and the work nearby. Jefferson County is home to most of Watertown (14,485 of its 22,704 residents), Fort Atkinson, Jefferson and Lake Mills. Construction employs 1,975, up 41.0% since 2019. 249 MW of new generation is planned here across 2 units, led by Badger State Solar LLC (solar), the 7th largest pipeline among Wisconsin's counties. 149 MW of it is already under construction or built. Electrical contractors employ 149, up 35.5% since 2019 against up 21.6% statewide, at an average $80,180 a year. Next door, Dane County has 9 data centers and 361 MW of planned generation.
Cities and towns in Jefferson County
Jefferson County is home to most of Watertown (14,485 of its 22,704 residents), Fort Atkinson, Jefferson and Lake Mills.
- Watertown also extends into Dodge County.
- Whitewater also extends into Walworth County.
- Cambridge also extends into Dane County.
Unincorporated communities (governed by the county): Hebron, Helenville, Ixonia, Lake Koshkonong, Lake Ripley, Rome.
Residents are 2025 Census estimates for the part of each city, town or township inside this county. Census publishes no annual estimate for unincorporated communities.
What changed in Jefferson County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Wisconsin |
|---|---|---|---|---|
| Population (2020 → 2025) | 86,219 | 86,505 | ▲ 0.3% | 20th of 72 by size |
| Total jobs (2019 → 2025) | 33,248 | 33,413 | ▲ 0.5% | 27th of 72 by growth |
| Average annual pay (2019 → 2025) | $42,052 | $56,423 | ▲ 34.2% | — |
| Construction jobs (2019 → 2025) | 1,401 | 1,975 | ▲ 41.0% | 10th of 61 by growth |
| Electrical contractor jobs (2019 → 2025) | 110 | 149 | ▲ 35.5% | — |
| Unemployment rate (2019 → August 2026) | 2.9% | 2.8% | ▼ 0.1pts | — |
| Generating capacity added since 2019 | — | 87 MW | — | |
| Generating capacity retired since 2019 | — | 0 MW | — | |
| Planned generation (Aug 2026) | — | 249 MW | 33% of today's fleet | 7th of 17 by size |
87 MW of that came online in 2019 or later, mostly solar. Its power plants have 760 MW of capacity, 88% of it natural gas, the 10th largest fleet in Wisconsin. Wisconsin Electric Power Co is the largest utility serving Jefferson County, one of 6 with territory here. Its residential customers paid an average 19.23¢/kWh in 2024, above the 13.25¢ median for Wisconsin utilities. Employers here counted 33,413 jobs in 2025, up 0.5% from 2019. Unemployment was 2.8% in August 2026, against 2.9% in 2019. 86,505 people live here, up 0.3% since 2020.
Who powers Jefferson County
Net change in operating capacity since 2019: +87 MW. Colors follow the fuel legend above.
Utilities with service territory in Jefferson County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Wisconsin Electric Power Co | Investor Owned | Bundled | 1,048,148 | 19.23¢ | 38% |
| Wisconsin Power & Light Co | Investor Owned | Bundled | 437,211 | 16.89¢ | 22% |
| Adams-Columbia Electric Coop | Cooperative | Bundled | 35,910 | 17.63¢ | 16% |
| Lake Mills Light & Water | Municipal | Bundled | 4,124 | 13.86¢ | 52% |
| Jefferson Utilities | Municipal | Bundled | 3,718 | 11.87¢ | 52% |
| Waterloo Light & Water Comm | Municipal | Bundled | 1,626 | 13.92¢ | 61% |
Customer counts, prices and sales shares cover each utility's whole system in the state, not only this county. Commercial sales include data centers.
Operating power plants 8
| Technology | Capacity | Share |
|---|---|---|
| Natural gas | 665 MW | 88% |
| Solar | 88 MW | 12% |
| Other technologies | 6 MW | 1% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| Concord | Wisconsin Electric Power Co | Natural gas | 382 MW | 1993 |
| Whitewater Generating Station | Wisconsin Electric Power Co | Natural gas | 284 MW | 1997 |
| Crawfish River | Wisconsin Power & Light Co | Solar | 75 MW | 2023 |
| Deertrack Park Gas Recovery | WM Renewable Energy LLC | Other technologies | 6 MW | 2006 |
| Hackbarth Solar WI, LLC | Wisconsin Electric Power Co | Solar | 5 MW | 2024 |
| Rock LakeSolar WI, LLC | Wisconsin Electric Power Co | Solar | 5 MW | 2025 |
Planned generation 2
| Plant | Technology | MW | Status | Year | Owner |
|---|---|---|---|---|---|
| Badger State Solar LLC | Solar Photovoltaic | 149 MW | Under construction (>50%) | 2027 | Badger State Solar LLC |
| Sinnissippi Solar Energy LLC | Solar Photovoltaic | 100 MW | Planned, approvals not started | 2028 | Invenergy Services LLC |
The Jefferson County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 33,413 | $56,423 | 1.00 |
| Construction | 1,975 | $76,906 | 1.12 |
| Electrical contractors | 149 | $80,180 | 0.62 |
Concentration is the BLS location quotient: 1.0 means the industry holds the same share of local jobs as it does nationally. Industry rows count private employers; cells BLS suppresses are left out.
Data centers and local rules in Jefferson County
No data center, local measure or delayed project is on record in Jefferson County. Wisconsin has 49 local measures on record statewide, and 3 neighboring counties have one: Dane County, Dodge County, Rock County.
Jefferson County and its neighbors
Of the 5 counties that border Jefferson County, Dane County carries the most build-out activity: data centers, planned generation and operating plants combined.
| County | Population | Jobs since 2019 | Operating MW | Planned MW | Data centers | Local measures |
|---|---|---|---|---|---|---|
| Jefferson County | 86,505 | ▲ 0.5% | 760 MW | 249 MW | — | — |
| Dane County | 590,375 | ▲ 4.9% | 1,172 MW | 361 MW | 9 | 2 |
| Dodge County | 89,097 | ▲ 3.7% | 337 MW | — | 1 | 1 |
| Rock County | 166,472 | ▲ 2.9% | 1,829 MW | — | — | 1 |
| Walworth County | 106,127 | ▲ 8.1% | 26 MW | 324 MW | — | — |
| Waukesha County | 417,210 | ▲ 1.1% | 4 MW | — | 1 | — |
More of Wisconsin
Jefferson County, answered from the record
Who provides electricity in Jefferson County, Wisconsin?
6 utilities have service territory in Jefferson County in the EIA-861 2024 report: Wisconsin Electric Power Co, Wisconsin Power & Light Co, Adams-Columbia Electric Coop, Lake Mills Light & Water. The largest, Wisconsin Electric Power Co, charged residential customers 19.23¢/kWh on average in 2024.
What county is Watertown, WI in?
Most of Watertown is in Jefferson County: 14,485 of its 22,704 residents, or 64%. The rest of the city lies in Dodge County.
What county is Fort Atkinson, WI in?
Fort Atkinson is in Jefferson County, Wisconsin. About 12,388 people live there (2025 Census estimate).
What power plants are in Jefferson County?
8 operating plants with 760 MW of capacity. The largest is Concord (382 MW, natural gas).
How much new power is planned in Jefferson County?
249 MW across 2 units in the August 2026 EIA-860M inventory, 149 MW of it under construction or built. The largest owner is Badger State Solar LLC.
Are there data centers in Jefferson County?
The SAVRN Data Center Map has no data center in Jefferson County. The nearest activity on record is next door in Dane County.
Is Jefferson County adding jobs?
Employers counted 33,413 jobs in 2025 against 33,248 in 2019 (+0.5%, BLS QCEW). Construction went from 1,401 to 1,975.
Does Jefferson County have a data center moratorium?
No county-level measure is on record for Jefferson County. Wisconsin has 49 local measures statewide, listed on the state page.