County annual report · FIPS 46137
2021 Ziebach County, SD Power Outage Report
In 2021, customers in Ziebach County, SD went without power for an average of 0.5 hours, a total of 650 customer-hours (South Dakota average 3.4 hours). That ranks 55th worst of 61 South Dakota counties and 2821st 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 Ziebach 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 | August 31, 2021 01:30 | August 31, 2021 06:30 | 5h | 33 | 125 |
| 2 | May 24, 2021 13:15 | May 24, 2021 14:15 | 1h | 31 | 31 |
| 3 | June 17, 2021 16:15 | June 17, 2021 16:45 | 30m | 31 | 16 |
| 4 | June 21, 2021 15:15 | June 21, 2021 19:00 | 3h 45m | 31 | 116 |
| 5 | July 12, 2021 12:30 | July 12, 2021 13:15 | 45m | 31 | 16 |
| 6 | July 14, 2021 12:00 | July 14, 2021 22:00 | 10h | 31 | 295 |
| 7 | January 14, 2021 21:45 | January 14, 2021 22:15 | 30m | 3 | 2 |
| 8 | April 11, 2021 14:45 | April 11, 2021 16:00 | 1h 15m | 3 | 4 |
| 9 | June 9, 2021 05:15 | June 9, 2021 12:45 | 7h 30m | 3 | 23 |
| 10 | June 29, 2021 14:15 | June 29, 2021 18:45 | 4h 30m | 1 | 5 |
Outage episodes by size in 2021: 0 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 Ziebach 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 River Electric Assn Inc | 2021 | 54 min | 0.72 | 54 min | 0.72 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Grand Electric Coop, Inc | - | - | - | - | - |
| Moreau-Grand 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 ÷ 1,374 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. Ziebach County has data for 2018–2025.
Cite this report
MassOutage (massoutage.com), Ziebach 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/ziebach-county