Union County, South Dakota: Power, Data Centers and the Local Economy
Home to Big Sioux Township, North Sioux City and Elk Point
Union 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. Construction employs 499, up 48.5% since 2019. Union County is home to Big Sioux Township, North Sioux City, Elk Point and most of Beresford (1,742 of its 2,105 residents). Next door, Woodbury County, Iowa, has 2 data centers. Electrical contractors employ 37, up 2.8% since 2019 against up 38.0% statewide, at an average $62,872 a year. Employers here counted 9,566 jobs in 2025, down 3.8% from 2019.
Cities and towns in Union County
Union County is home to Big Sioux Township, North Sioux City, Elk Point and most of Beresford (1,742 of its 2,105 residents).
- Beresford also extends into Lincoln County.
Unincorporated communities (governed by the county): Dakota Dunes, Richland.
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 Union County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in South Dakota |
|---|---|---|---|---|
| Population (2020 → 2025) | 16,855 | 17,402 | ▲ 3.2% | 13th of 66 by size |
| Total jobs (2019 → 2025) | 9,940 | 9,566 | ▼ 3.8% | 56th of 66 by growth |
| Average annual pay (2019 → 2025) | $56,078 | $74,563 | ▲ 33.0% | — |
| Construction jobs (2019 → 2025) | 336 | 499 | ▲ 48.5% | 6th of 31 by growth |
| Electrical contractor jobs (2019 → 2025) | 36 | 37 | ▲ 2.8% | — |
| Unemployment rate (2019 → August 2026) | 2.8% | 2.6% | ▼ 0.2pts | — |
Southeastern Electric Coop Inc - (SD) is the largest utility serving Union County, one of 7 with territory here. Its residential customers paid an average 12.41¢/kWh in 2024. Unemployment was 2.6% in August 2026, against 2.8% in 2019. 17,402 people live here, up 3.2% since 2020.
Who powers Union County
Utilities with service territory in Union County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Southeastern Electric Coop Inc - (SD) | Cooperative | Bundled | 20,160 | 12.41¢ | 26% |
| MidAmerican Energy Co | Investor Owned | Bundled | 4,236 | 8.68¢ | 20% |
| City of Beresford | — | — | — | — | — |
| Clay-Union Electric Corp | — | — | — | — | — |
| City of Elk Point | — | — | — | — | — |
| Union County Electric Coop Inc | — | — | — | — | — |
| WAPA-- Western Area Power Administration | Federal | Bundled | — | — | 99% |
Customer counts, prices and sales shares cover each utility's whole system in the state, not only this county. Commercial sales include data centers.
No operating power plant is located in Union County in the EIA-860M inventory. Its power comes over the grid from plants elsewhere.
The Union County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 9,566 | $74,563 | 1.00 |
| Construction | 499 | $73,714 | 0.98 |
| Electrical contractors | 37 | $62,872 | 0.54 |
| Data processing and hosting | 7 | $352,212 | 0.24 |
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 Union County
No data center, local measure or delayed project is on record in Union County. South Dakota has 4 local measures on record statewide, and 4 neighboring counties have one: Lincoln County, Plymouth County, Sioux County, Woodbury County.
Union County and its neighbors
Of the 7 counties that border Union County, Woodbury 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 |
|---|---|---|---|---|---|---|
| Union County | 17,402 | ▼ 3.8% | — | — | — | — |
| Clay County | 15,031 | ▲ 0.2% | 135 MW | — | — | — |
| Dakota County NE | 21,687 | ▲ 11.9% | 4 MW | — | — | — |
| Dixon County NE | 5,602 | ▼ 3.1% | 324 MW | — | — | — |
| Lincoln County | 77,145 | ▲ 27.9% | 4 MW | — | 1 | 1 |
| Plymouth County IA | 25,697 | ▲ 0.1% | 203 MW | — | — | 1 |
| Sioux County IA | 36,774 | ▲ 8.2% | — | — | — | 1 |
| Woodbury County IA | 106,649 | ▼ 1.7% | 1,284 MW | — | 2 | 1 |
More of South Dakota
Union County, answered from the record
Who provides electricity in Union County, South Dakota?
7 utilities have service territory in Union County in the EIA-861 2024 report: Southeastern Electric Coop Inc - (SD), MidAmerican Energy Co, City of Beresford, Clay-Union Electric Corp. The largest, Southeastern Electric Coop Inc - (SD), charged residential customers 12.41¢/kWh on average in 2024.
Are there data centers in Union County?
The SAVRN Data Center Map has no data center in Union County. The nearest activity on record is next door in Woodbury County.
Is Union County adding jobs?
Employers counted 9,566 jobs in 2025 against 9,940 in 2019 (-3.8%, BLS QCEW). Construction went from 336 to 499.
Does Union County have a data center moratorium?
No county-level measure is on record for Union County. South Dakota has 4 local measures statewide, listed on the state page.