Washington County, Illinois: Power, Data Centers and the Local Economy
Home to Nashville Township, Nashville and Okawville Township
No data center or power plant project is on record in Washington County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Washington County is home to Nashville Township, Nashville, Okawville Township and Okawville. Construction employs 345, up 36.9% since 2019. Employers here counted 6,218 jobs in 2025, down 6.6% from 2019. 5 MW of that came online in 2019 or later, mostly solar. Its power plants have 5 MW of capacity, 100% of it solar.
Cities and towns in Washington County
Washington County is home to Nashville Township, Nashville, Okawville Township and Okawville.
And 5 smaller places.
- Wamac also extends into Clinton County, Marion County.
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 Washington County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Illinois |
|---|---|---|---|---|
| Population (2020 → 2025) | 13,729 | 13,564 | ▼ 1.2% | 75th of 102 by size |
| Total jobs (2019 → 2025) | 6,654 | 6,218 | ▼ 6.6% | 82nd of 102 by growth |
| Average annual pay (2019 → 2025) | $48,491 | $61,812 | ▲ 27.5% | — |
| Construction jobs (2019 → 2025) | 252 | 345 | ▲ 36.9% | 9th of 56 by growth |
| Unemployment rate (2019 → August 2026) | 3.3% | 2.9% | ▼ 0.4pts | — |
| Generating capacity added since 2019 | — | 5 MW | — | |
| Generating capacity retired since 2019 | — | 0 MW | — |
Ameren Illinois Company is the largest utility serving Washington County, one of 4 with territory here. Its residential customers paid an average 15.26¢/kWh in 2024. Unemployment was 2.9% in August 2026, against 3.3% in 2019. 13,564 people live here, down 1.2% since 2020.
Who powers Washington County
Net change in operating capacity since 2019: +5 MW. Colors follow the fuel legend above.
Utilities with service territory in Washington County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Ameren Illinois Company | Investor Owned | Bundled | 1,060,894 | 15.26¢ | 28% |
| Tri-County Electric Coop, Inc (IL) | Cooperative | Bundled | 16,197 | 16.04¢ | 9% |
| Egyptian Electric Coop Assn | Cooperative | Bundled | 13,707 | 15.53¢ | 42% |
| Clinton County Elec Coop, Inc | — | — | — | — | — |
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 1
| Technology | Capacity | Share |
|---|---|---|
| Solar | 5 MW | 100% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| Ashley Solar LLC PV | Ashley Solar LLC PV | Solar | 5 MW | 2026 |
The Washington County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 6,218 | $61,812 | 1.00 |
| Construction | 345 | $73,170 | 1.05 |
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 Washington County
No data center, local measure or delayed project is on record in Washington County. Illinois has 28 local measures on record statewide.
Washington County and its neighbors
Of the 6 counties that border Washington County, St. Clair 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 |
|---|---|---|---|---|---|---|
| Washington County | 13,564 | ▼ 6.6% | 5 MW | — | — | — |
| Clinton County | 37,128 | ▲ 2.6% | 47 MW | 53 MW | — | — |
| Jefferson County | 36,147 | ▼ 2.4% | 2 MW | 155 MW | — | — |
| Marion County | 36,382 | ▼ 4.3% | 372 MW | — | — | — |
| Perry County | 20,160 | ▼ 5.2% | 535 MW | 168 MW | — | — |
| Randolph County | 29,921 | ▼ 9.4% | 1,504 MW | — | — | — |
| St. Clair County | 250,708 | ▼ 3.2% | 1,821 MW | 155 MW | — | — |
More of Illinois
Washington County, answered from the record
Who provides electricity in Washington County, Illinois?
4 utilities have service territory in Washington County in the EIA-861 2024 report: Ameren Illinois Company, Tri-County Electric Coop, Inc (IL), Egyptian Electric Coop Assn, Clinton County Elec Coop, Inc. The largest, Ameren Illinois Company, charged residential customers 15.26¢/kWh on average in 2024.
What power plants are in Washington County?
1 operating plant with 5 MW of capacity. The largest is Ashley Solar LLC PV (5 MW, solar).
Are there data centers in Washington County?
The SAVRN Data Center Map has no data center in Washington County.
Is Washington County adding jobs?
Employers counted 6,218 jobs in 2025 against 6,654 in 2019 (-6.6%, BLS QCEW). Construction went from 252 to 345.
Does Washington County have a data center moratorium?
No county-level measure is on record for Washington County. Illinois has 28 local measures statewide, listed on the state page.