ITC Midwest team effort restores significant transmission damage in record time following rare derecho storm
(August 27, 2020) - A rare and powerful storm – meteorologically called a derecho – caused severe damage across the heart of the ITC Midwest service footprint midday on Monday, August 10. The storm had the effect of a 40-mile wide tornado that caused severe damage and electric outages along a 200-mile stretch of the U.S. Highway 30 corridor, stretching from Boone, Iowa, eastward to the Mississippi River. Along with heavy rain, the storm packed sustained winds of 70 miles per hour for a period of 45 minutes. The National Weather Service calculated gusts of between 126 and 140 miles per hour – equivalent to the force of a category 4 hurricane.
Approximately 500,000 electricity customers – representing more than 30% of the state’s customer base – were initially without electric service in Iowa, including about 235,000 Alliant Energy customers. ITC Midwest initially had 145 transmission lines out of service. From large lattice structures down with 345 kV lines to wooden poles snapped with 34.5 kV lines, the outage affected 1,215 line miles of ITC Midwest lines of 69 kV or higher voltage – nearly 20% of the entire system. Widespread line damage was sustained in 26 counties in the ITC Midwest service territory.
ITC’s Emergency Operations Center was immediately activated with twice daily meetings, and the efforts began to assess damage to the system and prioritize the responses. Wheels started turning to move hundreds of semi-loads of materials from vendors and the company’s Michigan warehouses, as well as an army of utility workers from across the country. Within a short time, workers from ULCS and outside contractors, all supported by ITC field supervisors, engineers, supply chain team and other employees, were working 24/7 to restore the power.
Some highlights of the ITC Midwest response:
- More than 780 utility workers from across the country were on the ground to rebuild the transmission lines.More than 800 meals were served each day to these workers, who consumed 2,500 bottles of water daily.In addition, due to COVID-19, instead of double bunking, arrangements were made to provide each crew member with their own room.Due to the power outage, most hotels in the storm zone were closed, complicating the housing issue.
- A preliminary count shows more than 1,000 wooden and steel poles were used in the rebuild. The previous high was the replacement of 438 poles used in the April 2019 ice storm.
- ITC Midwest personnel remained in close communication with Alliant Energy, CIPCO, the rural electric cooperatives and the municipal utilities served by the company to safely coordinate the storm response.
Through a great deal of coordination and effort, the ITC team did what initially seemed impossible to achieve. ITC set out on a plan to restore electric service to the substations and the distribution companies by restoring priority lines and through switching service onto the repaired and working transmission lines, allowing service to be restored at a record pace.
As of 12:30 p.m. on Tuesday, August 18 – just eight days after the massive storm hit – ITC Midwest restored the last of the lines and circuits needed to provide service to ITC Midwest distribution customers. Thanks to the hard work of our utility crews, ITC Midwest delivered on its commitment to safely restore the transmission system by Tuesday night. Within another week, all except three lines of the 145 initially out of service had been repaired. Follow-up work will continue in the weeks ahead to ensure system resiliency and reliability. ITC Midwest also worked closely with Alliant Energy, CIPCO and the affected rural electric cooperatives and municipal utilities to help them get power restored to customers.
This was an achievement that was only possible through the hard work and dedication of the entire ITC team. This historic storm pushed the limits of our crews and operations teams, but we at ITC Midwest are incredibly proud and thankful for the progress they made in just over a week. And we’re incredibly proud that we did the work safely. The mobilization of ITC employees, contractor crews, and materials and resources set a new standard for performance, especially considering it was all done during a pandemic.