County annual report · FIPS 46085
2021 Lyman County, SD Power Outage Report
In 2021, customers in Lyman County, SD went without power for an average of 3.7 hours, a total of 11K customer-hours (South Dakota average 3.4 hours). That ranks 22nd worst of 61 South Dakota counties and 1628th 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 Lyman 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 | February 16, 2021 13:00 | February 16, 2021 14:30 | 1h 30m | 1,034 | 969 |
| 2 | March 14, 2021 22:30 | March 17, 2021 12:30 | 2d 14h | 839 | 4,789 |
| 3 | April 21, 2021 22:15 | April 21, 2021 22:45 | 30m | 463 | 232 |
| 4 | February 24, 2021 22:00 | February 24, 2021 22:30 | 30m | 397 | 199 |
| 5 | May 22, 2021 16:00 | May 24, 2021 12:45 | 1d 20h | 230 | 320 |
| 6 | June 18, 2021 11:45 | June 18, 2021 14:45 | 3h | 165 | 327 |
| 7 | January 30, 2021 13:00 | January 30, 2021 16:15 | 3h 15m | 161 | 444 |
| 8 | March 31, 2021 20:30 | April 1, 2021 00:30 | 4h | 140 | 77 |
| 9 | September 23, 2021 13:00 | September 23, 2021 21:00 | 8h | 136 | 166 |
| 10 | December 7, 2021 11:00 | December 9, 2021 15:15 | 2d 4h | 131 | 297 |
Outage episodes by size in 2021: 13 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 Lyman 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 |
|---|---|---|---|---|---|
| West Central Electric Coop Inc - (SD) | 2018 | 3.7 hrs | 1.25 | 1.5 hrs | 1.25 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Rosebud 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 ÷ 2,969 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. Lyman County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Lyman 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/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/south-dakota/lyman-county