County annual report · FIPS 46129
2021 Walworth County, SD Power Outage Report
In 2021, customers in Walworth County, SD went without power for an average of 3.3 hours, a total of 7,703 customer-hours (South Dakota average 3.4 hours). That ranks 25th worst of 61 South Dakota counties and 1762nd of 2,974 nationally.
Compared with SD, the US and 2020
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Walworth County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | October 14, 2021 05:45 | October 14, 2021 11:00 | 5h 15m | 2,454 | 5,494 |
| 2 | June 20, 2021 14:45 | June 20, 2021 15:30 | 45m | 441 | 330 |
| 3 | November 13, 2021 20:30 | November 13, 2021 21:30 | 1h | 228 | 227 |
| 4 | November 19, 2021 06:45 | November 19, 2021 09:30 | 2h 45m | 188 | 514 |
| 5 | November 3, 2021 18:30 | November 3, 2021 18:45 | 15m | 129 | 32 |
| 6 | February 4, 2021 00:00 | February 4, 2021 04:45 | 4h 45m | 119 | 548 |
| 7 | June 11, 2021 07:15 | June 11, 2021 11:30 | 4h 15m | 118 | 199 |
| 8 | February 3, 2021 22:15 | February 3, 2021 23:15 | 1h | 112 | 54 |
| 9 | July 26, 2021 17:30 | July 26, 2021 18:30 | 1h | 96 | 96 |
| 10 | March 4, 2021 02:15 | March 4, 2021 02:30 | 15m | 33 | 8 |
Outage episodes by size in 2021: 8 reached 100+ customers, 1 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Walworth County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Montana-Dakota Utilities Co | - | - | - | - | - |
| Cam Wal Electric Coop, Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 79% of South Dakota's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 2,370 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Walworth County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Walworth County, SD annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/). https://massoutage.com/reports/2021/south-dakota/walworth-county