County annual report · FIPS 46031
2021 Corson County, SD Power Outage Report
In 2021, customers in Corson County, SD went without power for an average of 0.2 hours, a total of 388 customer-hours (South Dakota average 3.4 hours). That ranks 57th worst of 61 South Dakota counties and 2889th 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 Corson County, 2021
The 9 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 07:00 | 1h 15m | 140 | 173 |
| 2 | January 14, 2021 21:45 | January 14, 2021 22:15 | 30m | 5 | 3 |
| 3 | January 15, 2021 15:30 | January 15, 2021 16:30 | 1h | 5 | 5 |
| 4 | June 11, 2021 10:00 | June 11, 2021 13:15 | 3h 15m | 5 | 16 |
| 5 | June 16, 2021 20:30 | June 16, 2021 21:15 | 45m | 5 | 4 |
| 6 | July 23, 2021 10:45 | July 23, 2021 13:00 | 2h 15m | 5 | 10 |
| 7 | July 24, 2021 20:15 | July 24, 2021 20:45 | 30m | 5 | 3 |
| 8 | July 27, 2021 15:45 | July 29, 2021 00:45 | 1d 9h | 5 | 165 |
| 9 | August 26, 2021 15:30 | August 26, 2021 17:30 | 2h | 5 | 10 |
Outage episodes by size in 2021: 1 reached 100+ customers, 0 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 Corson 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 |
|---|---|---|---|---|---|
| Montana-Dakota Utilities Co | - | - | - | - | - |
| Grand Electric Coop, Inc | - | - | - | - | - |
| Moreau-Grand Electric Coop Inc | - | - | - | - | - |
| City of McLaughlin - (SD) | - | - | - | - | - |
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 ÷ 1,975 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. Corson County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Corson 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/corson-county