Southern California Edison (SCE) crews had to take extra precautions while building the 35-mile Eldorado-Ivanpah Transmission Project, which runs through the heart of desert tortoise country in the Mojave Desert.

In the 110-degree summer heat, the shade beneath a work truck parked at a construction site can be awfully inviting to the desert tortoise, which has been designated a threatened species by both the state and federal governments. So accidentally harming even one could have temporarily shut down the entire $440-million, Eldorado-Ivanpah project, and with as many as 100 trucks involved in the project on any given day, crushing a tortoise by simply driving away from a work site was an ever-present risk.

“People think of tortoises as slow moving, but they can be pretty fast,” said SCE Senior Biologist Jack Goldfarb, a member of the utility’s 16-member Biological Resources Group, which is dedicated to mitigating SCE’s impact on wildlife. 

Safeguards were put in place during the year and a half that it took to complete the project. For example, drivers were provided orange cones displaying “LOOK OUT FOR TORTOISES” to place next to their vehicles every time they parked.

As an additional precaution, spotters were assigned to work trucks to help drivers avoid running over tortoises that were trying to cross the road. “If you look at the coloration of the tortoise in the road, it blends in pretty well,” Goldfarb said. “And if you’re driving, it can be pretty hard to see. So every truck larger than a pickup had a spotter riding shotgun.”

Such measures to minimize the utility’s impact on the desert tortoise were critical, he said, because without intervention the species will become extinct.

But state and federal restrictions that protect a threatened species can be a challenge, especially while trying to upgrade 35 miles of transmission lines between San Bernardino County and Boulder City, Nev.

When a tortoise happened to wander onto a work site, a trained biologist had to be called in to remove it. A scared tortoise will wet itself, which could cause it to die of dehydration if it can’t quickly find a source of water.

And if a desert tortoise burrow was discovered, it meant either moving the site a few feet or calling in a biologist to inspect the burrow for tortoises, then collapse the burrow. “It took a lot of effort and resources to get the project built on time, within budget and in compliance,” Goldfarb said. “During construction we did not harm or injure any tortoises, so that was a tremendous success.”