Construction on Phase 2 and Phase 3 of BrightSource Energy, Inc.’s 392-megawatt Ivanpah Solar Electric Generating System project were allowed to resume last week after the Bureau of Land Management (BLM) issued a Notice to Proceed after reevaluating the project’s impact on federally listed threatened desert tortoises.

The BLM added additional stipulations to mitigate risk to the tortoises, and BrightSource added additional protective steps. But the desert tortoises remain at risk, said at least one environmental group that filed a lawsuit over BLM’s approval of the project.

Earlier this year the Western Watersheds Project sued the Department of Interior, BLM and the U.S. Fish and Wildlife Service over FWS’s Biological Opinion, which the environmental group said underestimated how many desert tortoises would be impacted by the construction of the project.

BrightSource and Bechtel Power Corp. halted construction on the projects upon discovering more threatened desert tortoises at the Ivanpah site than originally anticipated.

Last week, the USFSW issued a new Biological Opinion that includes new stipulations for translocating the tortoises, added new requirements to protect them from predators and added increased monitoring and fencing requirements, BLM said in a press release.

“This new biological opinion allows the project to move forward without jeopardizing the tortoise, taking into account the higher number of animals found,” said BLM-California Acting State Director Peter Ditton.

But the Western Watershed Project isn’t appeased.

“The biological opinion itself recognizes that the data that the original opinion was based on was inadequate. If anything the new statement reinforces our concerns over the original biological impact statement,” said Dr. Michael Connor, California Director for Western Watersheds Project.

BrightSource said it has initiated a “Head-Start” program to protect the tortoise. The program finds tortoise eggs, incubates them and protects the neonates (hatchlings) from predators, monitors their growth and then protects the juvenile tortoises from predators. The program also moves or translocates tortoises to areas where they won’t be impacted by construction.

But that doesn’t guarantee the animals will survive, according to Connor.

“Only 50 percent of tortoise were alive a couple years after being translocated,” he said. Moving the tortoises also has a broader impact. “It doesn’t just impact those tortoises being moved, but also impacts tortoises at the site where they’re being moved to.”

Image courtesy of USFWS.