County annual report · FIPS 48491
2021 Williamson County, TX Power Outage Report
In 2021, customers in Williamson County, TX went without power for an average of 23.6 hours, a total of 7.1M customer-hours (Texas average 21.0 hours). That ranks 122nd worst of 252 Texas counties and 360th of 2,974 nationally.
Compared with TX, the US and 2020
Coverage line is EAGLE-I's share of Texas customers tracked each year.
Biggest outages in Williamson 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 11, 2021 14:15 | February 23, 2021 06:15 | 11d 16h | 134,418 | 6.3M |
| 2 | May 28, 2021 16:00 | May 31, 2021 07:15 | 2d 15h | 13,753 | 67K |
| 3 | April 28, 2021 12:45 | May 2, 2021 21:15 | 4d 8h | 12,458 | 24K |
| 4 | January 10, 2021 16:30 | January 12, 2021 06:45 | 1d 14h | 12,139 | 68K |
| 5 | October 28, 2021 13:30 | October 31, 2021 10:00 | 2d 20h | 10,927 | 54K |
| 6 | November 4, 2021 09:30 | November 5, 2021 00:15 | 14h 45m | 9,130 | 34K |
| 7 | April 1, 2021 13:00 | April 2, 2021 04:00 | 15h | 8,428 | 12K |
| 8 | September 28, 2021 20:30 | September 30, 2021 09:15 | 1d 12h | 8,198 | 32K |
| 9 | October 21, 2021 13:15 | October 21, 2021 23:45 | 10h 30m | 7,158 | 8,314 |
| 10 | December 18, 2021 07:45 | December 19, 2021 06:00 | 22h 15m | 6,664 | 5,666 |
Outage episodes by size in 2021: 198 reached 100+ customers, 87 reached 1,000+ customers, 5 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 Williamson 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 |
|---|---|---|---|---|---|
| Oncor Electric Delivery Company LLC | 2017 | 3.4 hrs | 1.69 | 2.4 hrs | 1.49 |
| Pedernales Electric Coop, Inc | 2021 | 2.5 hrs | 1.13 | 84 min | 1.13 |
| Bluebonnet Electric Coop, Inc | 2021 | 16.5 hrs | - | 1.6 hrs | 1.08 |
| Bartlett Electric Coop, Inc | 2021 | 29.0 hrs | 19.09 | 12.3 hrs | 0.50 |
| Austin Energy | 2021 | 32.0 hrs | 1.89 | 63 min | 0.76 |
| City of Bartlett - (TX) | - | - | - | - | - |
| City of Georgetown - (TX) | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 94% of Texas's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 299,583 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. Williamson County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Williamson County, TX 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/texas/williamson-county