Rare ‘derecho’ hits Colorado

A rare and strong storm hit much of Colorado in early June, causing outages throughout IREA’s service territory.

The storm, classified as a derecho, brought a record number of high wind gusts to the Front Range. According to the National Weather Service, a derecho is a long storm band characterized by widespread, long-lived winds and showers or thunderstorms. It typically includes numerous microbursts, downbursts and downburst clusters, and can cause destruction on par with tornadoes.

The June derecho, which extended 600 to 750 miles, is one of just a few in Colorado’s recorded history. Its destructive winds – most in excess of 60 mph – felled trees and damaged overhead lines in all four of IREA’s operating districts. More than 50 of IREA’s poles were broken; most were three-phase structures. Unlike typical storms, the derecho also damaged wires and other equipment.

Many of the broken poles could be reached only on foot. Without powered equipment, linemen had to manually dig holes and set new poles by hand. Some broken poles were in locations with heavy concentrations of rock. One area required the replacement of 12 poles, conductor line and several transformers.

Outages caused by the derecho affected nearly 12,000 IREA customers. IREA took an all-hands-on-deck approach in restoring service, enlisting the aid of contractor line crews, tree-trimming personnel and underground locating services. Crews worked as quickly as possible to restore service but were presented at times with extremely dangerous conditions that slowed their progress. This, combined with the magnitude and severity of damage to our system, caused extended outages for some customers.

We understand the frustration of extended service interruptions, and work to make our system more resilient. Our Advanced Metering Infrastructure (AMI), vegetation management program, system improvement projects and other efforts increase reliability. We also maintain an online Outage Center through which you can report service interruptions, sign up for text alerts and monitor outages.