Northwest Austin Edition | February 2023

LOSING POWER When Winter Storm Mara blew through Texas on Jan. 31-Feb. 2, it knocked out power for many residents in the area who use Austin Energy or Pedernales Electric Cooperative. Here is a look at how many customers were aected at the peak of outages for each service area.

management would not have made a huge dierence due to the severity of the storm. Michael Webber, a professor of mechanical engineering at The Uni- versity of Texas and a former AE com- missioner, said he believes overall the city-owned utility performed relatively well under the circumstances. Webber agreed a more aggressive trimming approach likely would not have made a signicant dierence in this year’s weather event due to heavy ice accumulation aecting trees and branches well outside the bounds of the vegetation program. However, council voted Feb. 9 to call for an audit into tree management. While moving power lines under- ground could run the city billions of dollars, Webber said it is something that should be seriously explored. “The undergrounding is more expensive upfront; it is slower to bring back if it goes down; it’s harder to do repairs underground than above ground. But it’s more robust; it fails less On Feb. 2, Sargent estimated all AE outages would be xed by Feb. 3 before announcing there was no timeline for repairs just hours later. Ocials reported 99% of outages were xed by Feb. 7, with a deadline to x “nearly all” of the outages by Feb. 12. The storm and its aftermath raised questions about AE’s communications system in emergencies, including direct customer notications and the capacity of its virtual outage map. Following a Feb. 7 brieng, Austin City Council further questioned AE on Feb. 21 about its storm response. Mayor Kirk Watson and other leaders have also called for AE’s internal after-action report to be released quickly. often,” he said. After the action

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communications, such as promising then backtracking on a timeline for total power restoration, and Austin’s storm response have built up. On Feb. 15, City Council red City Manager Spencer Cronk in part for his response to the storm. Weathering the storm Temperatures dropped below freez- ing Jan. 30 and hovered near 32 degrees until Feb. 3, according to National Weather Service data, and it rained over the next few days. More than half an inch of ice is con- sidered signicant for any part of the county, said Mack Morris, an Austin/ San Antonio NWS meteorologist. AE General Manager Jackie Sar- gent called the storm a “historic extreme.” Over 30% of AE custom- ers lost power, largely due to debris on power lines. The number of cus- tomers refers to a single meter. A customer represents 2.5 people on average, per industry standards. A PEC representative said the major- ity of the outages were caused by ice accumulation on lines and damages from falling sheets of ice. PEC ocials said Winter Storm Mara caused dam- age similar to what is seen with a hur- ricane or tornado. Soon after outages began, Sargent and other AE ocials began elding questions about vegetation manage- ment—or the utility’s responsibility to trim trees around power lines. In May 2019, Austin Council approved widening the tree trim- ming around power lines to 8 feet for fast-growing trees and 4 feet for slow-growing trees. At the time, AE ocials warned the trees were over- grown in many areas. AE has maintained better vegetation

Austin Energy

Pedernales Electric Cooperative

Overlapping coverage

County line

PEC peak 12,670 Williamson County members experienced outages Feb. 2

281 PEC peak 11,741 Travis County members experienced outages Feb. 2

183

195

Williamson County

130 TOLL

183

45 TOLL

Travis County

290

281

290

PEC peak 8,790

Hays County

304 AE peak 173,879 customers experienced outages Feb. 1

Hays County members experienced outages Feb. 2

130

MAP NOT TO SCALE

SOURCES: AUSTIN ENERGY, PEDERNALES ELECTRIC COOPERATIVECOMMUNITY IMPACT

HOW THE CITY WENT DARK

During Winter Storm Mara, ice and debris accumulated on power lines and knocked over poles. This led to more than 373,000 power outages. While Austin abides by a tree trimming protocol around power lines, it was behind on some vegetation management. The ice was so signicant it aected trees outside of the city’s management zone.

More than 0.5 inches of ice is considered signicant, according to the National ICE BUILDUP

183

195

Williamson

281

183

Half an inch of ice can add 500 pounds to an electrical wire.

Substation

Weather Service.

Travis

290

130 TOLL

Ice accumulation

KEY

290

0.75 in. 0.5 in.

Underground transformer

Accumulated ice

SOURCE: AUSTIN ENERGY COMMUNITY IMPACT

Fallen tree or limbs

Overhead transformer

Homes

SOURCE: NATIONAL WEATHER SERVICECOMMUNITY IMPACT

304

COMMUNITYIMPACT.COM

130